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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Commodity Protection and Quality Research » Research » Publications at this Location » Publication #318341
Research Project: Integrate Pre- and Postharvest Approaches to Enhance Fresh Fruit Quality and Control Postharvest Diseases

Location: Commodity Protection and Quality Research

Title: Botrytis californica, a new cryptic species in the B. cinerea species complex causing gray mold in blueberries and table grapes

Author
item SAITO, SEIYA - University Of California
item Margosan, Dennis
item MICHAILIDES, THEMIS - University Of California
item Xiao, Chang-Lin

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2015
Publication Date: 4/28/2016
Citation: Saito, S., Margosan, D.A., Michailides, T.J., Xiao, C. 2016. Botrytis californica, a new cryptic species in the B. cinerea species complex causing gray mold in blueberries and table grapes. Mycologia. 108:330-343. doi: 10.3852/15-165.

Interpretive Summary: Gray mold, caused by the fungus Botrytis cinerea, is a major disease of blueberries and table grapes. B. cinerea has been shown to consist of two sibling species, referred to as Group I and Group II, and Group I has recently been described as a new species B. pseudocinerea. During a survey for 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 than B. cinerea and B. pseudocinerea. In this study, we described these isolates as a new species, Botrytis californica, based on the morphological and molecular characteristics in comparison with B. cinerea, B. pseudocinerea, and other Botrytis species. Botrytis 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.

Technical Abstract: Botrytis cinerea consists of two cryptic species, referred to as Group I and Group II based on Bc-hch gene RFLP haplotyping, and Group I has been described as a new cryptic species B. pseudocinerea. During a survey for 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 B. cinerea and B. pseudocinerea. Therefore, in this study we characterized these six isolates in comparison 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 coding gene sequences, glyceraldehyde-3-phosate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2), supported the erection of a new Botrytis species, Botrytis californica Saito & Xiao, which is genetically closely related to B. cinerea, B. pseudocinerea, and B. sinoviticola, all of which are known as the causal agents of gray mold of grapes. Botrytis 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.