Poster: Diseases of Plants: New & Emerging Diseases
Botrytis californica, a new Botrytis species causing gray mold in blueberries and table grapes in California.
S. SAITO (1), D. Margosan (2), T. Michailides (3), C. Xiao (1) (1) USDA-ARS, San Joaquin Valley Agricultural Sciences Center, U.S.A.; (2) USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, U.S.A.; (3) Kearney Agricultural
The Botrytis cinerea species complex comprises two cryptic species, originally referred as Group I and Group II based on Bc-hch gene RFLP haplotyping. Group I was described as a new cryptic species B. pseudocinerea. During a survey of Botrytis spp. causing gray mold in blueberries and table grapes in the Central Valley of California, six isolates, three from blueberries and three from table grapes, were placed in Group I but showed a distinct morphological character with conidiophores significantly longer than those of B. cinerea and B. pseudocinerea. We compared these isolates with B. cinerea and B. pseudocinerea by examining morphological and physiological characters, sensitivity to fenhexamid, and phylogenetic analysis inferred from sequences of three nuclear genes. Phylogenetic analysis using the three partial gene sequences encoding glyceraldehyde-3-phosate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2), supported the proposal of a new Botrytis species, B. californica, which is genetically closely related to B. cinerea, B. pseudocinerea, and B. sinoviticola, all known as causal agents of gray mold of grapes. B. californica caused decay on blueberry and table grape fruit inoculated with the fungus. This study suggests that B. californica is a cryptic species sympatric with B. cinerea on blueberries and table grapes in California.