Category Archives: Plant Pathogens

Plant Pathology (plant diseases)

Colletotrichum fioriniae

California Pest Rating Proposal for

Colletotrichum fioriniae (Marcelino & Gouli) Pennycook 2017
Current Pest Rating: Z
Proposed Pest Rating: B


*Comment Period: 4/17/2019 through 6/1/2019


Author/Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:
  • Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:

Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

Posted comments will not be able to be viewed immediately.

Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence, including threats.

Comments may be edited prior to posting to ensure they are entirely germane.

Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: B


Posted by ls

Erysiphe peckii (U. Braun) U. Braun & S. Takam. 2000

California Pest Rating Proposal for

Erysiphe peckii (U. Braun) U. Braun & S. Takam. 2000
Current Pest Rating: Q

Proposed Pest Rating: B
*Comment Period: 4/4/2019 – 5/19/2019

Author/Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:
  • Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:

Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

Posted comments will not be able to be viewed immediately.

Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence, including threats.

Comments may be edited prior to posting to ensure they are entirely germane.

Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: B

Posted by ls

Alstroemeria necrotic streak virus

Alstroemeria necrotic streak virus
Current Pest Rating: Q
Proposed Pest Rating: A

*Comment Period: 4/3/2019 – 5/18/2019


Author/Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:
  • Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:

Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

Posted comments will not be able to be viewed immediately.

Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence, including threats.

Comments may be edited prior to posting to ensure they are entirely germane.

Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: A


Posted by ls

Ilyonectria capensis L. Lombard & Crous 2013

California Pest Rating Proposal

Ilyonectria capensis L. Lombard & Crous 2013  
Current Pest Rating: Q
Proposed Pest Rating: C


Comment Period:  2/22/2019 – 4/8/2019*


Author/Responsible Party:

John J. Chitambar, Primary PlantPathologist/Nematologist, California Department of Food and Agriculture, 3294Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:
Consequences of Introduction:  1. Climate/Host Interaction: 
[Your comment that relates to “Climate/Host Interaction” here.]


Posted comments will not be able to be viewed immediately.


Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the
    pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene, 
    pornographic, sexually oriented, threatening, racially offensive,
    discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or 
    other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence, 
    including threats.

Comments may be edited prior to posting to ensure they are entirely germane.


Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: C


Posted by ls 

Neocercosporidium smilacis (Thüm.) U. Braun, C. Nakash., Videira & Crous 2017

California Pest Rating Proposal

Neocercosporidium smilacis (Thüm.) U. Braun, C. Nakash., Videira & Crous 2017
Current Pest Rating: Q
Proposed Pest Rating: B


Comment Period: 2/22/2019 – 4/8/2019*

Author/Responsible Party:

John J. Chitambar, Primary PlantPathologist/Nematologist, California Department of Food and Agriculture, 3294Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:
 Consequences of Introduction:  1. Climate/Host Interaction: 
[Your comment that relates to “Climate/Host Interaction” here.]


Posted comments will not be able to be viewed immediately.


Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the
    pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene,
    pornographic, sexually oriented, threatening, racially offensive,
    discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or
    other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence,
    including threats.

Comments may be edited prior to posting to ensure they are entirely germane.


Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: B


Posted by ls 


Cucurbit Chlorotic Yellows Virus

California Pest Rating Proposal

Cucurbit chlorotic yellows virus
Current Pest Rating: Not Rated
Proposed Pest Rating: B


Comment Period: 2/20/2019 – 4/6/2019*


Author/Responsible Party:

John J. Chitambar, Primary PlantPathologist/Nematologist, California Department of Food and Agriculture, 3294Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

EXAMPLE COMMENT:
 Consequences of Introduction:  1. Climate/Host Interaction: 
[Your comment that relates to “Climate/Host Interaction” here.]


Posted comments will not be able to be viewed immediately.


Comments may not be posted if they:

  • Contain inappropriate language which is not germane to the
    pest rating proposal;
  • Contains defamatory, false, inaccurate, abusive, obscene,
    pornographic, sexually oriented, threatening, racially offensive,
    discriminatory or illegal material;
  • Violates agency regulations prohibiting sexual harassment or
    other forms of discrimination;
  • Violates agency regulations prohibiting workplace violence,
    including threats.

Comments may be edited prior to posting to ensure they are entirely germane.


Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: B


Posted by ls 

Gymnosporangium yamadae

California Pest Rating Proposal

Gymnosporangium yamadae Miyabe ex G. Yamada 1904
Current Pest Rating: Q
Proposed Pest Rating: A


Comment Period: 1/18/2019 – 3/4/2019*


Responsible Party:

John J. Chitambar, Primary PlantPathologist/Nematologist, California Department of Food and Agriculture, 3294Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Proposed Pest Rating: A


Posted by ls 

Tomato Brown Rugose Fruit Virus

California Pest Rating for
Tomato Brown Rugose Fruit Virus
Pest Rating:      A

PEST RATING PROFILE

Initiating Event:

On September 25, 2018, Tongyan Tian, CDFA Plant Pathologist, was notified by Kai-Shu Ling, Plant Pathologist, USDA ARS, Charleston, South Carolina, of his detection of Tomato brown rugose fruit virus (ToBRFV) in a tomato plant tissue sample sent to him by a private company in California.   The sample had been collected from tomato plants grown in the company’s greenhouse in Santa Barbara County.  On September 13, 2018, the company had also sent an unofficial symptomatic tomato leaf sample to CDFA for diagnosis of the associated pathogen. On November 2, 2018, Tongyan Tian, CDFA, identified the associated pathogen as Tomato brown rugose fruit virus. On further investigation of the situation in California, CDFA was notified by the company that all ToBRFV-infested and symptomatic plant material had been voluntarily destroyed, thereby preventing the collection of an official sample. Nevertheless, the risk associated with the possible introduction of ToBRFV and a proposed rating for this pathogen is documented here.

History & Status:

Background:  Tomato brown rugose fruit virus is a relatively new Tobamovirus – the genus that bears other economically important and contagious pathogens that infect Solanaceae, such as Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV). ToBRFV was initially isolated from tomato plants grown in greenhouses in Jordan in 2015 (Salem et al., 2016).  Prior to this, in 2014, an outbreak of a new disease infecting resistant tomato cultivars grown in net houses was observed in Southern Israel and was determined to be caused by the Israeli isolate of ToBRFV with high genomic sequence identity to the Jordan isolate (Luria et al., 2017).  Most recently, ToBRFV was detected in tomato and chili pepper plants growing in nurseries in Yurecuaro, Michoacan, Mexico (NAPPO, 2018).  There have been no previous reports of ToBRFV from the USA. The recent detection in greenhouse tomato plants in California that subsequently resulted in the destruction of all infested plants, does not verify the establishment of ToBRFV in the country (see ‘Initiating Event’).

Tobamoviruses infecting tomato are of great concern, but ToBRFV is of special concern because of its ability to overcome resistance of the TM-22 resistance gene which is genetically bred into tomato plants for resistance against Tobamoviruses (Luria et al., 2017).  The Israeli isolate of ToBRFV was found to infect pepper (Capsicum annuum) plants harboring the L resistance genes, when cultivated in contaminated soil from previous grown infected tomato plants, especially in hot temperatures above 30°C (Luria et al., 2017).  Disease caused by ToBRFV is infectious and local spread can occur rapidly through mechanical means (see ‘Dispersal and spread’).

Hosts:  Tomato (Solanum lycopersicum) and pepper (Capsicum annuum) are the main hosts (Salem et al., 2016; Luria et al., 2017; NAPPO, 2018).  Petunia (Petunia hybrida) and certain weeds like black nightshade (S. nigrum) were shown to be asymptomatic hosts in experiments (Luria et al., 2017).

Symptoms:  The Jordan isolate of ToBRFV in tomato caused mild foliar symptoms and strong brown rugose symptoms on fruit thereby affecting market value of the crop.   Mechanically inoculated plants exhibited a range of local and systemic symptoms (Salem et al., 2016).  Symptoms caused by the Israeli isolate of ToBRFV were mild and severe mosaic of leaves with occasional narrowing of the leaves.  Yellow spots on fruit affected 10-15% of the total number of fruit produced on symptomatic plants (Luria et al., 2017).

In pepper plants cultivated in ToBRFV-contaminated soil from previously grown infected tomato plants, especially in temperatures above 30°C, the hypersensitivity response included necrotic lesions on roots and stems resulting in inhibited plant growth and possibly plant collapse.  Petunia and certain weeds are symptomless hosts, while eggplant and potatoes are non-hosts for the virus (Luria et al., 2017).

Dispersal and spread: ToBRFV is transmitted mechanically (plant to plant) via externally contaminated seed (over long distances), common cultural practices (worker’s hand, clothes), tools, equipment and circulating water (Salem et al., 2016).  Tobamoviruses are capable of preserving infectivity in seeds and contaminated soil (Broadbent, 1976; Luria et al., 2017).  Weed hosts can serve as reservoirs of inoculum for infection of the main hosts.

Damage Potential: Tobamoviruses are of main concern in tomato crops, especially when cultivated in protected environments such as greenhouses, where conditions favor rapid spread of the pathogen.  The ability of ToBRFV to break resistance in tomato plants harboring the TM-22 resistance gene and, under certain conditions also pepper plants harboring the L resistance genes, makes the potential for damage a main concern. The stability and infectious nature of this Tobamovirus via mechanical transmission by workers, tools and equipment during the handling of plants, with infection most likely occurring when seedlings are thinned in nurseries or transplanted, plus transmission through contaminated seed, soil and circulating water, render a high potential for damage in tomato and pepper.  Crop production and quality of ToBRFV-consumable tomato and pepper fruit can be affected thereby significantly impacting their market value.

Worldwide Distribution: Asia: Jordan (Salem et al., 2016), Israel (Luria et al., 2017); North America: Mexico (NAPPO, 2018).

Official Control: None reported.

California Distribution: Tomato brown rugose fruit virus is not present in California.  The detection of ToBRFV in greenhouse tomato plants in Santa Barbara County resulted in the destruction of the plants (see ‘Initiating Event’).

California Interceptions: None reported.

The risk Tomato brown rugose fruit virus would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: It is likely that Tomato brown rugose fruit virus can establish a widespread distribution in California wherever tomato and pepper plants are cultivated.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The main hosts of ToBRFV are tomato and pepper cultivars.  Experimentally, petunia and few weeds have been proven to be asymptomatic hosts and weeds may serve as reservoirs of inoculum for subsequent infections of main cultivated hosts.

Evaluate the host range of the pest.

Score: 1

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Tomato brown rugose fruit virus is a stable and readily infectious virus plant pathogen. It is easily transmitted from plant to plant by mechanical means which include common cultural practices, contaminated tools, equipment, hands, clothes, soil, and infected plants, and seed. Infections most likely occur in protected environments, where favorable conditions for pathogen spread exist, as when seedlings are thinned in nurseries or transplanted. Transmission of ToBRFV by insect vectors has not been reported.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: ToBRFV can break resistance in tomato plants harboring the TM-22 resistance gene and under certain conditions, also pepper plants harboring the L resistance genes. The stability and infectious nature of this Tobamovirus render a high potential for damage in tomato and pepper particularly under protected environments such as greenhouses.  Crop production and quality of ToBRFV consumable tomato and pepper fruit can be affected thereby significantly impacting their market value.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, C, D, G.

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: The natural host range is limited to tomato and pepper which are cultivated crops.  Home/urban gardening of these host plants may be impacted if infected with ToBRFV. Consequently, the establishment of this resistance-breaking Tobamovirus species in California could trigger additional official or private treatment programs.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: D, E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Tomato brown rugose fruit virus:

Add up the total score and include it here. 13

-Low = 5-8 points

-Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Evaluation is ‘0’.  ToBRFV is not established in California.

Score: 0

Not established (0) Pest never detected in California or known only from incursions.

-Low (-1) Pest has a localized distribution in California or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 13

Uncertainty:  

The potential for weed plants, especially those commonly found in tomato and pepper fields in California, to serve as hosts and inoculum reservoirs of the pathogen is not known.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Tomato brown rugose fruit virus is A.


References:

Broadbent, L.  1976.  Epidemiology and control of Tomato mosaic virus.  Annual Review of Phytopathology, 14:75-96.

Luria, N. Smith, E., Reingold, V., Bekelman, I., Lapidot, M., Levin, I., Elad, N., Tam., Y., Sela, Abu-Ras, A., Ezra, N., Haberman, A., Yitzhak, L., Lachman, O. and Dombrovsky, A.  2017.  A new Israeli Tobamovirus isolate infects tomato plants harboring Tm-22 resistance genes.  PLoS ONE 12 (1):e0170429.  doi:10.1371/journal.pone.0170429

NAPPO. 2018. Tomato Brown Rugose Fruit Virus: detected in the municipality of Yurecuaro, Michoacan. North American Plant Protection Organization (NAPPO) Phytosanitary Alert System.  September 17, 2018. https://www.pestalerts.org/oprDetail.cfm?oprID=765.

Salem, N., Mansour, A., Ciuffo, M., Falk, B. W., and Turina, M.  2016.  A new Tobamovirus infecting tomato crops in Jordan.  Archives of Virology, 161:503-506.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

11/07/18 – 12/22/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: A


Posted by ls 

Cercospora insulana Sacc. 1915

California Pest Rating for
Cercospora insulana Sacc. 1915
Pest Rating: C

PEST RATING PROFILE

Initiating Event: 

On May 11, 2018 a postal shipment of statice dried flowers showing symptoms of leaf spots was intercepted by the CDFA at a Federal Express (FedEx) office.  The shipment was destined to a private owner in Alameda County and had originated in Hawaii.  A sample of the symptomatic flowers was sent to the CDFA Plant Pathology Lab for disease diagnoses.  On May 17, 2018 Cheryl Blomquist, CDFA plant pathologist, identified the fungus, Cercospora insulana associated with the leaf spots.  The present status and rating of C. insulana is reevaluated here.

History & Status:

Background:  Cercospora insulana is a fungal plant pathogen in the Mycosphaerellaceae family, that causes leaf spot of statice and other host plants.

The pathogen is globally widespread.  In the USA, Cercospora insulana has only been reported from Florida and California (Farr & Rossman, 2018).  In California, prior to its most recent detection, the pathogen has been reported on Armeria sp. and Limonium spp. in northern and southern coastal region of California (French, 1989).

Disease cycle: In general, plants infected with Cercospora species produce conidiophores (specialized hypha) that arise from the plant surface in clusters through stomata and form conidia (asexual spores) successively.  Conidia are easily detached and blown by wind often over long distances.  On landing on surfaces of a plant host, conidia require water or heavy dew to germinate and penetrate the host.  Substomatal stroma (compact mycelial structure) may form from which conidiophores develop.  Development of the pathogen is favored by high temperatures and the disease is most destructive during summer months and warmer climates.  High relative humidity is necessary for conidial germination and plant infection.  The pathogen can overwinter in or on seed and as mycelium (stromata) in old infected leaves (Agrios, 2005).   

Dispersal and spread: Dispersal and spread: air-currents, infected nursery plants, infected leaves, seeds (Agrios, 2005).

Hosts: Armeria sp., A. maritima (thrift seapink), Limonium sp., L. bonducellii (Algerian statice), L. californicum (California sea lavender/marsh rosemary), L. gmelinii (syn. Statice gmelinii; Siberian statice), L. sinuatum (syn. Statice sinuata; statice/wavyleaf sea lavender), L. vulgare (common sea lavender) (CABI, 2018; French, 1989); Nerium indicum (Indian oleander) (XueWen et al., 2017)

Symptoms:  Leaf spot symptoms caused by Cercospora insulana in field-grown statice were reported from Italy as circular, brown lesions with a darker edge, 3-6 mm in diameter and surrounded by an orange or reddish halo.  Old lesions enlarged and coalesced, causing yellowing and senescence of leaves.  Heavy infections resulted in severe defoliation and retarded growth or death in panicles. Lesions were also present on the wings of the flower scapes, while scapes proper were not involved (Nicoletti et al., 2003).

Damage Potential: Quantitative losses due to Cercospora insulana have not been reported.  If left uncontrolled, leaf spotting may lead to disease outbreaks under favorable conditions, wherein photosynthetic areas can be reduced.  Heavy infections may result in severe defoliation, retarded plant growth and death of flowers in statice, and likely, in other ornamental host plants.  Nursery productions of ornamental hosts under controlled and conducive conditions for pathogen development would also be of concern in California.  However, damage potential due to this pathogen is likely to be similar to other Cercospora diseases which is usually low (Agrios, 2005).  Furthermore, fungicide applications and sanitary measures including the use of clean seed have been used to successfully control Cercospora diseases (Agrios, 2005).

Worldwide Distribution: Asia: China (XueWen et al., 2017), India, Myanmar; Africa: Kenya, Malta, South Africa, Zimbabwe; Europe: Caucasus, Italy, Portugal, Russia: North America: USA (California, Florida), Haiti; Oceania: Australia, New Zealand (Farr & Rossman, 2018)

Official Control: Presently, Cercospora insulana is on the ‘Harmful Organism’ list for Brazil, Colombia, Ecuador and Israel (USDA PCIT, 2018).

California Distribution:  Cercospora insulana is distributed in northern and southern coastal areas of the State (French, 1989).

California Interceptions To date, the recent detection of C. insulana (see ‘initiating event’) has been the only interception reported.

The risk Cercospora insulana would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Cercospora insulana has only been detected in northern and southern coastal regions in California. These limited regions provide adequate moisture that favor development of the pathogen in host plants like statice.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The known host range is limited to statice, thrift seapink and Indian oleander in the genera Limonium, Armeria and Neria.

Evaluate the host range of the pest. Score: 1

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Cercospora insulana has high reproductive potential resulting in the successive production of conidia which primarily depend on air currents, infected plants and seed for dispersal and spread.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Quantitative losses due to Cercospora insulana have not been reported. However, for nurseries particularly, infected host plants with leaf spots could result in lowered value resulting in use of fungicidal treatments thereby increasing production costs, and loss of markets.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: B, C

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Home garden plantings of statice species may be impacted if the pathogen was to establish under favorable environmental conditions and in the absence of adequate disease control.  The pathogen has not been detected in oleander in California.

Evaluate the environmental impact of the pest on California using the criteria below.

Environment Impact: E 

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Cercospora insulana:

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction to California = 10

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Evaluation is ‘Medium’ in California.

Score: (-2)

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 8

Uncertainty:  

None.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Cercospora insulana is to continue as C.


References:

Agrios, G. N.  2005.  Plant Pathology (Fifth Edition).  Elsevier Academic Press, USA.  922 p.

Farr, D.F., & A. Y. Rossman.  2016.  Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA.  Retrieved May 18, 2018, from http://nt.ars-grin.gov/fungaldatabases/

French, A. M. 1989. California Plant Disease Host Index. California Department of Food and Agriculture, Sacramento (Updated online version by T. Tidwell, May 2, 2017).

Nicoletti, R., F. Raimo, C. Pasini, and F. D’Aquila.  2003.  Occurrence of Cercospora insulana on statice (Limonium sinuatum) in Italy.  Plant Pathology 52: 418.  DOI: 10.1046/j.1365-3059.2003.00840.x

USDA PCIT.  2018.  USDA Phytosanitary Certificate Issuance & Tracking System. Retrieved May 18, 2018. 12:45:06 pm CDT.  https://pcit.aphis.usda.gov/PExD/faces/ReportHarmOrgs.jsp.

XueWen, X., Z. Qian and G. YingLan.  2017.  New records of Cercospora and Pseudocercospora in China.  Mycosystema 36: 1164-1167.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

9/13/18 – 10/28/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: C


Posted by ls 

Citrus Viroid V

California Pest Rating  for
Citrus viroid V
Pest Rating: B

PEST RATING PROFILE

Initiating Event:  

The risk of infestation of Citrus viroid V (CVd-V) in California is evaluated and a permanent rating is herein proposed. 

History & Status:

Background: The origin of Citrus viroid V (CVd-V) is uncertain (Serra et al., 2008a).  In a study in Spain on the response of Citrus species and citrus-related genera to viroid infections, Serra and other researchers (2008a) originally detected CVd-V in Atalantia citroides, a citrus relative plant propagated on rough lemon rootstock and graft-inoculated with artificial mixtures of different viroids.  The viroid source was provided to them by a researcher at the University of California, Riverside and purified preparations were shown to be infectious in Etrog citron (Citrus medica), a classical indicator plant of citrus viroids.  Subsequently, CVd-V was considered a new species of the genus Apscaviroid in the family Pospiviroidae (Serra et al., 2008a).  Viroids are classified within two families: Pospiviroidae and Avsunviroidae.  Citrus are natural hosts of several viroid species that belong to the family Pospiviroidae.  Therefore, A. citroides was identified as an unusual viroid host since it was resistant to all previously known citrus viroids, yet capable of replicating CVd-V (Serra et al., 2008b).  Infectious assays conducted by Sierra et al. (2008) showed that CVd-V in Etrog citron exhibited mild symptoms, however, co-infections with either Citrus bent leaf viroid (CBLVd) or Citrus dwarfing viroid (CDVd, previously Citrus viroid III), also belonging to the genus Apscaviroid, showed synergistic effects in contrast to single infections of CVd-V or the other two viroids, however, titers of the viroids remained the same in singly or doubly infected plants (Serra et al., 2008a).

While the origin of CVd-V is not known, Pakistan may be one of the geographic origins of the viroid (Serra et al., 2008a, b; Parakh et al., 2017).  Serra et al. (2008a) suggested that the viroid was present, but overlooked or unnoticed, in field sources containing Hop stunt Viroid or Citrus dwarfing viroid – both of which have electrophoretic mobilities similar to CVd-V.  CVd-V has been found with some variations in its nucleotide sequence, in several countries in Africa, Asia, Europe, and North America (see ‘Worldwide Distribution).

In June 2016, the Citrus Clonal Protection Program-National Clean Plant Network (CCPP-NCPN), University of California, Riverside, California detected Citrus Viroid V in citrus budwood samples submitted by the CDFA for virus and viroid testing under the mandatory California (CA 3701) Citrus Nursery Stock Pest Cleanliness Program.  These budwood samples were taken from asymptomatic redblush grapefruit (Citrus paradisi) and variegated calamondin (C. madurensis) from a nursery in Tulare County.  This find marked the natural occurrence of CVd-V in California and corroborated the earlier report of CVd-VCA variant in the State (Dang et al., 2018; Serra et al., 2008b).

Hosts: Citrus spp.  including ‘Sanguinelli’, Salustiana’, and ‘Ricart navelina’ sweet oranges (Citrus x sinensis),  ‘Oroval’ and ‘Hernandina clementines (C. clementina), ‘Fino’ and ‘Verna’ lemons (C. limon), ‘Sevilano’ and ‘Cajel’ sour orange (C. aurantium), ‘Clausellina’ satsuma (C. unshiu), Temple mandarin (C. temple), Tahiti lime, Palestine sweet lime (C. limettioides), calamondin (C. madurensis), ‘Calabria’ bergamot (C. bergamia), ‘Orlando’ tangelo (C. paradisi x C. tangerina), ‘Page’ mandarin [(C. paradisi x C. tangerina) x C. clementina], and ‘Nagami’ kumquat (Fortunella margarita),  and Etrog citrus (Atlantia citroides) (Serra et al., 2008); ‘Shiranui’ [(C. unshiu x C. sinensis) x C. reticulata] (Ito and Ohta, 2010); ‘Moro blood’ sweet orange (Citrus x sinensis) (Bani Hashemian et al., 2013); redblush grapefruit (C. paradisi) (Dang et al., 2018).

Symptoms:   Citrus viroid V induced mild characteristic symptoms of very small necrotic lesions and cracks, sometimes filled with gum, in the stems of the viroid indicator plant, Etrog citron.  However, CVd-V reacted synergistically when Etrog citrus was co-infected with either citrus bent leaf viroid (CBLVd) or Citrus dwarfing viroid (CDVd), and showed severe stunting and epinasty with multiple lesions in the midvein.  Plants co-infected with CBLVd and CVd-V exhibited severe stem cracking characteristic of CBLVd, but without gum exudates, whereas plant co-infected with CDVd showed necrotic lesions (Serra et al., 2008a). Symptoms induced by CVd-V alone in commercial species and varieties are presently not known since commercial trees may be co-infected with several viroids (Ito and Ohta, 2010; Serra et al., 2008a).  Citrus viroid V may be present in asymptomatic citrus plant tissue – as recently evidenced by its detection in asymptomatic budwood collected from Tulare County, California.

Damage Potential:  The effect of CVd-V in commercial citrus rootstock-scion combinations, alone and in combination with other viroids, is yet unknown, however, Serra et al. (2008b) suggested that CVd-V could reduce tree size and yield as has been reported for clementine trees grafted on trifoliate orange co-infected with several viroids. Therefore, the need for nursery planting stock free of CVd-V is important.

Transmission:  Similar to other citrus viroids, CVd-V is graft-transmitted and is spread mainly through the propagation of infested material.

Worldwide Distribution:  Africa: Oman (Serra et al., 2008), Tunisia (Hamdi et al., 2015); Asia: China, Japan, Nepal, Pakistan (Cao et al., 2013), Iran (Bani Hashemian et al., 2010), Turkey (Önelge and Yurtmen, 2012); Europe: Spain (Serra et al., 2008); North America: USA (Serra et al., 2008).

Official Control: Citrus viroid V is a disease agent of concern that is tested for in the CDFA Citrus Nursery Stock Pest Cleanliness Program (3 CCR §§ 3701, et seq.).

California Distribution Tulare County (Dang et al., 2018).

California Interceptions: None reported.

The risk Citrus viroid V would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Citrus viroid V is likely to establish within infested propagative citrus materials in all citrus-growing regions of California.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Citrus viroid V has a moderate host range that is limited to several species and varieties of Citrus.

Evaluate the host range of the pest.

Score: 2

– Low (1) has a very limited host range.

Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Citrus viroid V replicates autonomously within infested plants and is spread mainly through the propagation and movement of infested planting materials to non-infested regions.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 2

– Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: The effect of CVd-V in commercial citrus rootstock-scion combinations, alone and in combination with other viroids, is yet unknown, however, it has been suggested by Serra et al. (2008b) that CVd-V could reduce tree size and yield.

Evaluate the economic impact of the pest to California using the criteria below.

Score: A, B, C

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: It is probable that home, urban, public garden and landscape plantings of CVd-V-infested citrus plantings may be significantly impacted by the viroid singly or in combination with other viroids.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Citrus Viroid V

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction of CVd-V to California = 12.

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (Score)

-Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Evaluation is Low (-1)Currently, Citrus viroid V has only been detected in a nursery in Tulare County.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 11.                                                                             

Uncertainty: 

The effect of CVd-V in commercial citrus rootstock-scion combinations, alone and in combination with other viroids, is yet unknown.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Citrus viroid V is B.


References:

Bani Hashemian, SM, Taheri, H, Duran-Vila, N, and Serr, P.  2010.  First report of Citrus viroid V in Moro blood sweet orange in Iran.  Plant Disease 94: 129.

Cao, M. J., Liu, Y. Q., Wang, X. F., Yang, F. Y., and Zhou, C. Y.  2010.  First report of Citrus bark cracking viroid and Citrus viroid V infecting Citrus in China.  Plant Disease 94: 922. https://doi.org/10.1094/PDIS-94-7-0922C

Dang, T., Tan, S. H., Bodaghi, S., Greer, G., Lavagi, I., Osman, F., Ramirez, B., Kress, J., Goodson, T., Weber, K., Zhang, Y. P., Vidalakis, G.  First report of Citrus Viroid V naturally infecting grapefruit and calamondin trees in California.  Plant Disease, Posted online on August 10, 2018. https://doi.org/10.1094/PDIS-01-18-0100-PDN

Hamdi, I., Elleuch, A., Bessaies, N., Grubb, C. D., and Fakhfakh, H. 2015. First report of Citrus viroid V in North Africa. Journal of General Plant Pathology 81, 87

Ito, T., and Ohta, S.  2010.  First report of Citrus viroid V in Japan.  Journal of General Plant Pathology 76: 348-350.

Önelge, N., and Yurtmen, M. 2012. First report of Citrus viroid V in Turkey. Journal of Plant Patholology 94 (Suppl. 4), 88.

Parakh, D. B., Zhu, S., and Sano, T.  2017.  Geographical distribution of viroids in South, Southeast, and East Asia.  In: Apscaviroids Infecting Citrus Trees by Tessitori, M, Viroids and Satellites, Edited by Hadidi, A, Flores, R, Randles, JW, and Palukaitis, P, Academic Press Ltd-Elsevier Science Ltd, Pages 243-249

Serra, P., Barbosa, C. J, Daros, J. A., Flores, R., Duran-Vila, N. 2008a. Citrus viroid V: molecular characterization and synergistic interactions with other members of the genus Apscaviroid. Virology 370, 102112.

Serra, P., Eiras, M., Bani-Hashemian, S. M., Murcia, N., Kitajima, E.W., Daro`s, J. A., et al., 2008b. Citrus viroid V: occurrence, host range, diagnosis, and identification of new variants. Phytopathology 98, 11991204.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-738-6693, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

9/13/18 – 10/28/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

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♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: B


Posted by ls 

Corynespora cassiicola (Berk. & M. A. Curtis) C. T. Wei 1950

California Pest Rating for
Corynespora cassiicola (Berk. & M. A. Curtis) C. T. Wei 1950
Pest Rating: B

 


PEST RATING PROFILE

Initiating Event: 

On September 27, 2017, a shipment of desert rose (Adenium obesum) plants showing symptoms of leaf spot disease was intercepted by San Diego Agricultural County inspectors.  The shipment had originated in Florida and was destined to a private company in San Diego County.  A sample of symptomatic plant leaves was collected by the San Diego Agriculture County and sent to the CDFA Plant Pathology Laboratory in Sacramento.  On October 18, 2017, the fungus, Corynespora cassiicola, was identified by CDFA plant pathologist, Suzanne Latham, to be associated with the leaf spot symptoms. A temporary ‘Q’ rating was assigned to the pathogen and consequently, the shipment was destroyed.  Corynespora cassiicola was previously detected on May 7, 2008, in an intercepted shipment of Mandevilla plants that originated in Florida and was destined to a nursery in San Diego County.  This detection marked the first report of the pathogen in California and resulted in the destruction of the shipment.  The current rating and consequences of introduction of C. cassiicola in California are assessed here and a permanent rating is proposed.

History & Status:

Background:  Corynespora cassiicola is a fungal plant pathogen that attacks a wide range of plants from tropical and subtropical countries causing leaf spot disease in several economically important crops under different common names such as Corynespora leaf spot of cucumber and several other hosts, blotch disease of cucurbits, stem and fruit spot of eggplant, papaya and target spot of tomato and cotton.  The fungus has been found in plant leaves, stems, fruit, roots, nematode cysts, and human skin and comprises many isolates.  Majority of isolates reported have been obtained from lesions or from fulfilled Koch postulate trials and are known to be plant pathogens.  However, isolates have also been reported from dead organic matter and non-symptomatic plant tissue and some can be both depending on the host substrate (Dixon et al., 2009).  Isolates may vary in virulence in host specificity.  Some isolates that specifically parasitize weed hosts without affecting agricultural crops may serve as potential bioherbicides agents (Smith & Schlub, 2005).  In South-east Asia, C. cassiicola causes leaf fall disease of rubber, which is one of the most serious leaf diseases of rubber in that region.

The pathogen was first described as Helminthosporium cassiicola by Berkeley and Curtis in 1868, and subsequently underwent several taxonomic changes to now be known as Corynespora cassiicola (Farr & Rossman, 2018). This pathogen is ubiquitous and has been reported to cause major economic losses in more than 70 countries (Dixon et al., 2009).

Disease cycle:  The pathogen survives in infested plant materials for more than two years.  High humidity, warm temperature (25-32°C) and long days are necessary for conidia production, infection and disease development.  Fluctuating day and night temperatures favor disease development (Williams, 1996).  The disease develops in tomatoes at favorable temperatures of 20-28°C and infection can occur at 16-32°C.  Extended periods of 16 to 44 hours of high moisture are necessary for optimum disease development (Pernezney et al., 2014).

Dispersal and spread: Infested planting stock, plant material, plant debris.  Conidia (spores) are airborne and seedborne (Daughtrey et al., 1995).

Hosts: More than 530 plant species from 380 genera including monocots, dicots, ferns, and one cycad have been reported to support growth of C. cassiicola (Dixon et al., 2009). Economically important host crops for California include Cucumis sativus (cucumber), Cucurbita moschata (pumpkin), C. moschata (pumpkin), C. pepo (marrow), cucurbits, Gossypium sp. (cotton), Solanum lycopersicum (tomato), S. melongena (eggplant) and ornamentals (CABI, 2018; Farr & Rossman, 2018).  Ornamental hosts include Aeschyanthus pulcher (lipstick vine), Aphelandra squarrosa (zebra plant), Catharnathus roseus (Madagascar periwinkle), Begonia, Hydrangea macrophylla (bigleaf hydrangea), Euphorbia pulcherrima (poinsettia), Saintpaulia ionantha (African violet) and Salvia splendens (scarlet sage) (Daughtrey et al., 1995)

Symptoms:  The initial symptoms of target spot in tomato are pinpoint-size, water-soaked lesions on the upper surfaces of leaves. These lesions increase in size, turn circular and pale brown with individual yellow halos.  Over time lesions coalesce and tissue may collapse while the leaflet remains attached to the petiole. Similar lesions may develop on petioles and stems resulting in rapid collapse of affected leaflets.  Lesions can develop on young fruit and resemble those caused by abiotic factors. These lesions are initially dark, sunken, pinpoint and brown and may later develop into craters. On ripe fruit, large, circular lesions develop with pale brown centers that crack and over time create avenues for secondary invading pathogens (Pernezny et al., 2014).  In infected cucurbits, initial lesions are angular yellow spots with light brown centers and dark brown borders.  As these lesion age, they drop out. Young and green fruit are not susceptible however, early infection of the blossom end of fruit may result in shriveling and darkening of the infected area with dark sporulation (Williams, 1996).  On ornamental plants such as poinsettia, lesions may be irregular, large and brown on bracts and primarily at the tips and margins of leaves; on hydrangea lesions may be small, reddish purple, circular with tan centers and reddish-purple margins; on African violets lesions are irregular and brown (Daughtrey et al., 1995).

Damage Potential: In the USA, reports of losses from target spot of field tomatoes are restricted to the Southeast which is frequented with high humidity and warm temperature climate (Pernezny et al., 2014). In California, if left uncontrolled, Corynespora disease development is likely to occur in greenhouses under favorable temperature and high humidity conditions. Impact of disease caused by this pathogen may be mitigated through proper sanitation, use of resistant varieties and regular applications of fungicidal treatments.

Worldwide Distribution: Asia: Bangladesh, Brunei Darussalam, Cambodia, China, India, Indonesia, Japan, Republic of Korea, Laos, Malaysia, Maldives, Myanmar, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam, Yemen; Africa: Benin, Cameroon, Congo, Democratic Republic of Congo, Côte d’Ivoire, Egypt, Ethiopia, Gabon, Ghana, Guinea, Liberia, Mauritius, Nigeria, Seychelles, Sierra Leone, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia; Central America and Caribbean:  Antigua and Barbuda, Barbados, Belize, British Virgin Islands, Costa Rica, Cuba, Dominica, El Salvador, Guadeloupe, Guatemala, Haiti, Honduras, Jamaica, Nicaragua, Puerto Rico, Trinidad and Tobago, United States Virgin Islands; Europe: Austria, Bulgaria, Denmark, France, Germany, Hungary, Italy, Netherlands, Norway, Romania, Russian Federation, United Kingdom, Ukraine; North America: Canada, Mexico, USA; Oceania: American Samoa, Australia, Fiji, Guam, Micronesia, New Zealand, northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Vanuatu; South America: Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Venezuela (CABI, 2018).

In the United States, C. cassiicola has been reported from Alabama, Florida, Hawaii, Illinois, Iowa, Louisiana, Minnesota, Mississippi, Nebraska, New York, North Carolina, North Dakota, South Carolina, Tennessee, Virginia, and Wisconsin (CABI, 2018).

Official Control: Corynespora cassiicola is on the ‘Harmful Organism Lists” for Israel, Namibia, South Africa and Vietnam (USDA PCIT, 2018).

California Distribution: Corynespora cassiicola has not been reported from California.  The pathogen is not known to be established in California.

California Interceptions:  There have been two interceptions of plants infected with Corynespora cassiicola (see: ‘Initiating Event’).

The risk Corynespora cassiicola would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Corynespora cassiicola requires prolonged periods of high humidity (16-44 hours) and warm temperature (25-32°C) for disease development. These climatic conditions would limit the ability of the pathogen to establish and spread within California.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score: 1

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The pathogen has a very wide and diverse host range that comprises more than 530 plant species from 380 genera including monocots, dicots, ferns, and one cycad. Economically important host crops for California include cucurbits, cotton, tomato, eggplant and ornamentals.

Evaluate the host range of the pest.

Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: Conidia are produced in abundance and are dispersed by air currents, infected seeds, host plant material and debris. Therefore, a high score is given to this category.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Plant damage caused by cassiicola is more likely under prolonged periods of high humidity and warm temperatures found in greenhouse cultivation than in open field environments of the state. If left uncontrolled, infections by the pathogen could result in lower crop yield and value resulting in the loss of markets. However, the administration of proper control measures may mitigate impact of damage caused by this pathogen.  Therefore, a medium score is given to this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact:  No significant impact to the environment is likely as the requirements of prolonged, high humidity and warm temperatures would considerably limit the ability of cassiicola to establish within the state.  

Evaluate the environmental impact of the pest on California using the criteria below.

Environment Impact:  None

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 1

Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Corynespora cassiicola:

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction to California = 10

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Evaluation is ‘Not established’ in California and has only been detected in intercepted plant shipments to the State.

Score: (0)

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 10

Uncertainty:

None.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Corynespora cassiicola is B.


References:

Agrios, G. N.  2005.  Plant Pathology (Fifth Edition).  Elsevier Academic Press, USA.  922 p.

Daughtrey, M. L., Wick, R. L., and Peterson, J. L.  1995.Corynespora leaf spot of Catharanthus, Hydrangea, Poinsettia, and SaintpauliaIn, Compendium of Flowering Potted Plant Diseases. APS Press, The American Phytopathological Society 90p.

Dixon, L. J., Schlub, R. L., Pernezny, K., and Datnoff, L. E.  2009.  Host specialization and phylogenetic diversity of Corynespora cassiicola.  Phytopathology 99: 1015-1027.

Farr, D.F., and Rossman, A. Y.  2016.  Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA.  Retrieved August 1, 2016, from http://nt.ars-grin.gov/fungaldatabases/

Pernezny, K. L., Blazquez, C. H., Smith, L. J., and Schlub, R. L.  2014).  Target spot.  In, Compendium of Tomato Disease and Pests Second Edition, Edited by J. B. Jones, T. A. Zitter, T. M. Momol, and S. A. Miller. 44-46p.

Smith, L. J., and Schlub, R. L. 2005. Foliar fungi on weeds of Guam and the potential for Corynespora cassiicola as a bioherbicide for   Stachytarpheta jamaicensis. (Abstr.) Phytopathology 95: S93.

USDA PCIT.  2017.  USDA Phytosanitary Certificate Issuance & Tracking System. Retrieved May 23, 2018. 11:53:45 am CDT.  https://pcit.aphis.usda.gov/PExD/faces/ReportHarmOrgs.jsp.

Williams, P. H.  1996.  Target leaf spot.  In, Compendium of Cucurbit Diseases, Ed. T. A. Zitter, D. L. Hopkins, and C. E. Thomas.  APS Press, The American Phytopathological Society p 31-32.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

5/31/18 – 7/15/18


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Pest Rating: B

 


Posted by ls 

 

 

Grapevine Pinot gris Virus (GPGV)

California Pest Rating  for
Grapevine Pinot gris Virus (GPGV)
Pest Rating: B

 


PEST RATING PROFILE

Initiating Event:   

A pest risk assessment and rating for Grapevine pinot gris virus (GPGV) was recently requested by Joshua Kress, CDFA Pest Exclusion Branch, in response to notification received on January 24, 2018, from Foundation Plant Service (FPS), on the detection of GPGV in their Foundation grapevine plants.  The risk of infestation of GPGV in California is evaluated and a permanent rating is herein proposed. 

History & Status:

Background: Although symptoms of stunting, chlorotic mottling, and leaf deformation had been observed on V. vinifera ‘Pinot gris’, in Trentino, North Italy since 2003, it was not until 2012 that Grapevine pinot gris was first detected by deep sequencing in one symptomatic and one symptomless grapevine, Vitis vinifera cv. Pinot gris in Northern Italy. In this initial study, GPGV was associated with field symptoms of chlorotic mottling and leaf deformation, reduced yield and low quality of berries, however the plant was also associated with several other viruses and viroids.  Furthermore, since GPGV was found in both symptomatic and symptomless plants from three different grape cultivars in a limited field survey, the virus could not be directly associated with the observed symptoms (Giampetruzzi et al., 2012; Glasa et al., 2014). This was further confirmed by Saldarelli et al. (2013) who reported 70% of GPGV-infected asymptomatic veins in cultivars Traminer and Pinot gris vineyards in Italy.  Bianchi et al. (2015) also detected GPGV in symptomatic and asymptomatic plants over a 3-year period in a field survey of productive vineyards and scion mother plant nurseries in Italy, however, the mean quantity of the virus was significantly higher in symptomatic vines than in asymptomatic plants. Consequently, a critical level or quantity of virus could not be associated with symptom expression.  Scientists in Italy determined that GPGV isolates that produce symptoms can be genetically differentiated from those that are asymptomatic (Saldarelli et al., 2015).

Grapevine pinot gris virus belongs to the genus Trichovirus in the family Betaflexiviridae.  Its full-length sequence was described and shown to be phylogenetically closely related to, yet molecularly different from Grapevine berry inner necrosis virus, another Trichovirus which was found in Japan and is transmitted by eriophyid mites (Giampetruzzi et al., 2012).  Since its original description in Italy, GPGV has been detected from symptomatic and asymptomatic grapevine cultivars in several countries in Europe and Asia, and few in North America, South America and Australia (see: ‘Worldwide Distribution’).

Grapevine Pinot gris virus (GPGV) was detected in California grapevine in Napa Valley and diagnosed by a testing service lab in Yolo County.  An informal report of this detection was made in 2015 (Rieger, 2015) and in a ‘list of pathogens report’ submitted by a testing service lab to the CDFA.  A formal first report of GPGV infecting grapevine was made in 2016 (Rwahnih et al., 2016) and marked a first detection of GPGV in the United States.  In 2016, Rwahnih and other scientists at the Foundation Plant Services screened 2,014 vines, including 23 vines of Pinot gris for the possible presence and prevalence of GPGV in the collections of FPS, which are the source of all certified grapevine plants produced in California.  Of all the vines tested, only one relatively rare, asymptomatic vine variety ‘Touriga Nacional” was found positive for GPGV. This vine had been imported from Portugal in 1981.  The risk of GPGV spread in commercial vineyards was considered low, given the very low prevalence of the pathogen in the FPS collection, however, the need for a large-scale survey of commercial vineyards in California was emphasized, as well as, the need for research to evaluate the effect of the virus on grapevine performance and wine quality.  Since cv ‘Touriga Nacional’ is rarely used in commercial vineyards, Angelini et al., (2016) molecularly surveyed 96 grapevine samples from four commercial wine grape vineyards in Napa Valley, California and reported the presence of GPGV in three cultivars, ‘Chardonnay’, ‘Cabernet Sauvignon’, and ‘Cabernet Franc’.

Grapevine pinot gris virus was recently detected in Foundation grapevine plants at FPS (see ‘Initiating Event’).  Subsequently, FPS removed all source vines from the Foundation vineyard and initiated monitoring of the site with additional testing implemented to detect and destroy any further detection and contain possible spread of the pathogen (personal communication: M. Al Rwahnih, Foundation Plant Services).

HostsGrapevine pinot gris virus has been found in at least 28 wine and table grape varieties of Vitis vinifera and hybrids. including Pinot gris, Pinot noir, Traminer, Chardonnay, Merlot, Chardonnay, Cabernet Franc, Cabernet Sauvignon, Carmenere Glera (Prosecco), Sauvignon Blanc and Shiraz (AWRI, 2018).

Symptoms:   Grapevines infected with GPGV may be symptomatic or asymptomatic.    Furthermore, specific symptoms caused by GPGV have been difficult to assign as GPGV-infected grapevines were infected with other viruses. Because of this, definitive symptoms have not been attributed to GPGV alone.  Symptoms putatively associated with GPGV include chlorotic mottling, leaf deformation, delayed bud-burst, stunted growth, reduced yields and low quality of berries with increased acidity (Saldarelli et al., 2015; AWRI, 2018).

Damage Potential:  The complete impact of GPGV on grapevine health is currently unknown and further research is need in this area (AWRI, 2018).  In Europe and Asia, GPGV and other concomitant viruses infesting grapevines have been associated with field observations of reduced yield, poor fruit set, poor quality and inner necrosis of berries (Giampetruzzi et al., 2012).  In Slovenia, the disease was reported to cause considerable economic losses (Mavrič Pleško et al., 2014).  Presently, the risk of spread of GPGV is considered low and the distribution of the virus has only been reported from commercial vineyards within Napa County (Al Rwahnih et al., 2016; Angelini et al., 2016).

TransmissionGrapevine Pinot gris virus is spread through movement of infected plant propagative material and by graft transmission.  There is the possibility of GPGV transmission by the eriophyid mite Colomerus vitus, like the other grapevine-infecting Trichovirus, Grapevine berry inner necrosis virus, however, this has not been confirmed.  Colomerus vitus commonly infests grapevine and has been reported in California.

Worldwide Distribution: Asia: China, South Korea, Georgia, Pakistan; Europe: Bosnia, Croatia, Czech Republic, France, Germany, Greece, Italy, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Turkey, Ukraine; North America: Canada, USA (California); South America: Brazil; Oceania: Australia. (Al Rwahnih et al., 2016; Angelini et al., 2016; Beuve et al., 2015; CABI, 2018; Casati et al., 2015; EPPO, 2018; Fan et al., 2016; Gazel et al., 2016; Lou et al., 2016; Mavrič Pleško et al., 2014; Rasool et al., 2017; Reynard, et al., 2016; Rius-Garcia & Olmos, 2017; Wu et al., 2017; Xiao et al., 2016).

Official Control: None reported.

California Distribution:  Napa County.

California Interceptions: There are no CDFA records of detection of GPGV in quarantine shipments of plant material intercepted in California.

The risk Grapevine Pinot gris virus would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Grapevine pinot gris virus is expected to be able to establish wherever wine and table grape varieties are cultivated in California, and therefore, is likely to establish a wide spread distribution.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Grapevine pinot gris virus has been found in at least 28 wine and table grape varieties of Vitis vinifera and hybrids. including Pinot gris, Pinot noir, Traminer, Chardonnay, Merlot, Chardonnay, Cabernet Franc, Cabernet Sauvignon, Carmenere Glera (Prosecco), Sauvignon Blanc and Shiraz. It’s known pest host range is evaluated as very limited.

Evaluate the host range of the pest.

Score: 1

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: GPGV is transmitted artificially through grafting and infested planting stock.  The involvement of a vector, an eriophyid mite Colomerus vitus, although likely, has not been confirmed. The virus has high reproduction within symptomatic and asymptomatic plants.  Therefore, a ‘High’ rating is given to this category.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: The economic impact of GPGV is not currently known and requires further research.  This is mainly due to evidence that the virus is present in both symptomatic and symptomless grape plants, and that other viruses and viroids may be present within the same plant infested by GPGV.  Nevertheless, putative symptoms of chlorotic mottling, leaf deformation, stunted growth, reduced yields and low quality of berries, have been associated with GPGV infestations.  This may relate to potentially lowering crop value and yield in production.  While the virus may be present in commercial vineyards of Chardonnay and Cabernet Sauvignon in California (Angelini et al., 2016), its risk of spread is considered low and its general impact on production is presently unknown.  Nursery production of grapevines may be affected.

Evaluate the economic impact of the pest to California using the criteria below.

Score: A, B

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: No impact to the environment is expected.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: None

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 1

Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Grapevine Pinot gris virus

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction of GPGV to California = Medium (10).

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (Score)

-Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Evaluation is Low (-1). Presently, Grapevine pinot gris virus has been reported only from Napa County.

Final Score

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 9. 

Uncertainty: 

Several aspects of Grapevine pinot gris virus are yet not known and require further research. In general, the impact of the virus on grape production, symptoms, prevalence and distribution within California are not fully known.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Grapevine Pinot gris virus is B.


References:

AWRI.  2018.  Grapevine pinot gris virus. Fact Sheet, Viticulture.  The Australian Wine Research Institute.  Updated February 2018.

Al Rwahnih, M., D. Golino, and A. Rowhani.  2016.  First report of Grapevine Pinot gris virus infecting grapevine in the United States.  Plant Disease (Posted online on March 4, 2016).  http://dx.doi.org/10.1094/PDIS-10-15-1235-PDN.

Angelini, E., N. Bertazzon, J. Montgomery, X. Wang, A. Zinkl, J. Stamp, and A. Wei.  2016.  Occurrence of Grapevine Pinot gris virus in commercial vineyards in the United States.  Plant Disease (Posted online on March 23, 2016): http://dx.doi.org/10.1094/PDIS-01-16-0055-PDN.

Beuve, M., T. Candresse, M. Tannières, and O. Lemaire.  2015.  First report of Grapevine Pinot gris virus (GPGV) in grapevine in France.  Plant Disease 99:293. http://dx.doi.org/10.1094/PDIS-10-14-1008-PDN.

Bianchi, G. L., F. De Amicis, L. De Sabbata, N. Di Bernardo, G. Governatori, F. Nonino, G. Prete, T. Marrazzo, S. Versolatto and C. Frausin.  2015.  Occurrence of Grapevine Pinot gris virus in Friuli Venezia Giulia (Italy): Field monitoring and virus quantification by real-time RT-PCR.  EPPO Bulletin 45:22-32.   DOI: 10.1111/epp.12196.

Casati, P., D. Maghradze, F. Ouaglino, A. Ravasio, O. Failla and P. A. Bianco.  First report of Grapevine pinot gris virus in Georgia.  Journal of Plant Pathology 1 (1). DOI: 10.4454/JPP.V98I1.003

EPPO.  2018.  Grapevine Pinot gris virus (GPGV00).  EPPO Global Database. https://gd.eppo.int/taxon/GPGV00/distribution

Fan, X. D., Y. F. Dong, Z. P. Zhang, F. Ren, G. J. Hu, Z.N. Li, and J. Zhou.  2016.  First report of Grapevine Pinot gris virus in Grapevines in China.  Plant Disease 100:540. http://dx.doi.org/10.1094/PDIS-08-15-0913-PDN.

Gazel, M., K. Caǧlayan, E. Elci, and L. Ozturk.  2016.  First Report of Grapevine Pinot gris virus in Grapevine in Turkey.  Plant Disease 100:657. http://dx.doi.org/10.1094/PDIS-05-15-0596-PDN.

Glasa, M., L. Predajňa, P. Komínek, A. Nagyová, T. Candresse and A. Olmos.  2014.  Molecular characterization of divergent grapevine Pinot gris virus isolated and their detection in Slovak and Czech grapevines.  Archives of Virology 159: 2103-2107.

Giampetruzzi, A., V. Roumia, R. Roberto, U. Malossinib, N. Yoshikawac, P. La Notte, F. Terlizzi, R. Credid, and P. Saldarelli.  A new grapevine virus discovered by deep sequencing of virus- and viroid-derived small RNAs in cv Pinot gris.  Virus Research 163:262-268.

Lou, B. H., Y. Q. Song, A. J. Chen, X. J. Bai, B. Wang, M. Z., Wang, P. Liu and J. J. He.  2016.  First report of Grapevine pinot gris virus in commercial grapevines in Southern China.  Journal of Plant Pathology 98: 677-697.

Mavrič Pleško, I., M. Viršček Marn, G. Seljak, and I. Žežlina.  2014.  First report of Grapevine Pinot gris virus infecting grapevine in Slovenia.  Plant Disease 98:1014.  http://dx.doi.org/10.1094/PDIS-11-13-1137-PDN.

Rasool, S., S. Naz, A. Rowhani, D. A. Golino, N. M. Westrick, K. D. Farrar and M. Al Rwahnih.  2017.  First report of Grapevine pinot gris virus infecting grapevine in Pakistan.  Plant Disease 101: 1958.

Rieger, T.  2015.  New grapevine virus detected in California: Grapevine Pinot Gris Virus discussed at UCD FPS meeting.  http://www.winebusiness.com/news/?go=getArticle&dataid=160912.

Reynard, J. -S, S. Schumacher, W. Menzel, J. Fuchs, P. Bohnert, M. Glasa, T. Wetzel and R. Fuchs.  2016.  First report of Grapevine pinot gris virus in German vineyards.  Plant Disease 100: 2545.

Ruiz-García, A. B., and A. Olmos.  2017.  First report of Grapevine pinot gris virus in Grapevine in Spain.  Plant Disease 101: 1070.

Saldarelli, P., A. Giampetruzzi, M. Morelli, U. Malossini, C. Pirolo, P. Bianchedi, and V. Gualandri.  2015.  Genetic variability of Grapevine Pinot gris virus and its association with grapevine leaf mottling and deformation.  Phytopathology 105:555-563. http://dx.doi.org/10.1094/PHYTO-09-14-0241-R.

Xiao, H., M. Shabanian, W. McFadden-Smith, and B. Meng.  2016.  First report of Grapevine Pinot gris virus in commercial grapes in Canada.  Plant Disease (Posted online on February 29, 2016). http://dx.doi.org/10.1094/PDIS-12-15-1405-PDN.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

5/22/18 – 7/06/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: B

 


Posted by ls