gubler_esca_talk

gubler_esca_talk - Esca (Black Measles)-Newly found...

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Unformatted text preview: Esca (Black Measles)-Newly found pathogen causes ancient disease of grapevines W.D.Gubler, Eskalen, and S.Rooney-Latham Department of Plant Pathology, University of California, Davis, CA 95616. Esca symptoms on Grapevine Esca Fruit symptoms Fruit History of Esca History ► Described by Greeks and Romans ► Mentioned in the Bible — Firing of the vine and shriveling of the fruit ► Disease primarily in Mediterranean climates ► First described in CA in 1940’s ► First research in the 1950’s Esca Esca ► Found in all production areas of California ► Incidence as high as 50 percent in some table grape vineyards but generally less in wine grape vineyards. ► Occurs in 2-80 yr-old vineyards. ► Incidence has increased in the past 12-15 years. ► Increased incidence correlated with loss of Sodite (sodium arsenite) for control. Esca Esca ► Was originally associated with wood rotting basidiomycetes in California ► No symptoms have been reproduced with basidiomycetes in California. ► Foliar and fruit symptoms have been reproduced in California with Togninia Togninia minima (Phaeoacremonium aleophilum). Locations of perithecia of Togninia spp. on grapevines . Anamorph Teleomorph P. aleophilum (Crous et al 1996) Togninia minima (Hausner et al 1992, Rooney et al 2003, Mostert et al. 2003) Anamorph Teleomorph P. mortoniae (Groenewald et al. 2001) Togninia fraxinopennsylvanica (Hausner et.al. 1992)(Eskalen et al. 2005) Anamorph Teleomorph P. viticola Togninia viticola sp. nov. Eskalen et al. 2006 Spores of Phaeoacremonium spp. and Phaeomoniella chlamydospora were trapped in infected vineyards of California MADERA 2003 50 45 40 P.viticola Precipitation (mm) Temperature (°C) 100 80 70 60 50 40 30 20 10 0 123412341234123412341234123412341234123412341234 Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Number of colonies 35 30 25 20 15 10 5 0 SONOMA 2003 50 45 40 P.viticola Precipitation (mm) Temperature (°C) 100 90 80 70 60 50 40 30 20 10 0 Number of colonies 35 30 25 20 15 10 5 0 123412341234123412341234123412341234123412341234 Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Temperature °Cand precipitation (mm) Temperature °Cand precipitation (mm) 90 Phaeoacremonium spp. Pruning wounds are susceptible for new inoculation . Fruit Symptoms Fruit ► Reproduced using culture filtrate. ► Inject directly into fruit or rachis ► Symptoms occurred within 7 days Togninia spp. (T.fraxinopennsylvanica and T.viticola) were isolated from symptomatic ash trees around vineyards P. viticola Declining ash trees (Fraxinus latifolia) were examined for perithecia Togninia viticola Conclusions Conclusions Pa causes fruit and foliar symptoms of esca. Pa Pathogen newly described on grapevines. Pathogen Pathogen is an endophyte Pathogen Pa causes vascular discoloration in spurs and Pa cordons. Symptoms occur in the year that new infections Symptoms occur thus the sporadic nature of symptom expression. Pathogens also occur on other hosts including ash Pathogens and laurel Pathogen Pathogen ► Togninia ascospores with rainfall from Oct-June ► Also spores have been trapped in the absence of rainfall in mid summer. ► Have been shown to be potentially insect vectored. Mites Mites Termites Termites minima and related spp release Esca - Pathogen Esca Togninia spp. reside as perithecia in Togninia exposed vascular tissue including pruning wounds and other exposed vascular tissue. Pathogen has been found to also reside as Pathogen epiphyte on leaves, fruit, and bark. Pathogen is an endophyte and is capable of Pathogen causing severe disease under vine stress conditions. Perithecia of Togninia davisea (sp nov) Perithecia Togninia were found on ash (Fraxinus latifolia) in Davis Phylogenetic similarity based on beta-tubulin region among Phaeoacremonium species 93 P. angustius 78 98 100 52 CBS100947 CBS101737 100 CBS101739 T. viticola sp. nov (P.viticola). AEbtL5 CCP933886 53 AEbtL3 100 AEbtQ8 AEbtF66 AEbtF55 91 CBS24995 100 Togninia sp. nov. MC3 AEbtL2 PD1B Phaeoacremonium sp. nov. AEbtQ6 100 AEH5 Togninia minima (Phaeoacremonium OVC8 CBS101358 100 Togninia sp.nov.. OVC5A AEbtA113 AEbtF58 T. fraxinopennsylvanica (P. mortoniae) AEB115 100 CBS21197 ISMF1B AEbtF12 P. inflatipes MFI 65 AEbtQ12 100 CBS113273 100 CBS39171 ISMF1A 84 L4A CBS16675 ISMFIE P. alvesii ISMF18 CBS72997 100 CBS40878 CBS110034 CBS113590 100 CBS112046 P. scolyti CBS49894 P. amstelodamense 92 AH5 CBS112585 CBS110627 P. subulatum CBS113587 100 P. venezuelense CBS113589 CBS113598 54 100 CBS110119 P. krajdenii CBS110368 CBS63393 CBS110367 aleophilum) TL: 948 CI: 0.622 RI: 0.891 RC: 0.554 HI: 0.378 CBS27033 10 changes ...
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This note was uploaded on 09/29/2010 for the course VEN 81437 taught by Professor Larrywilliams during the Fall '10 term at UC Davis.

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