|WANG, XUEFEI - Washington State University|
|GLAWE, DEAN - Washington State University|
|KRAMER, ELIZABETH - Washington State University|
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2018
Publication Date: 6/4/2018
Citation: Wang, X., Glawe, D.A., Kramer, E., Weller, D.M., Okubara, P.A. 2018. Biological control of Botrytis cinerea: interactions with native vineyard yeasts from Washington State. Phytopathology. https://apsjournals-apsnet-org.nal.idm.oclc.org/doi/pdf/10.1094/PHYTO-09-17-0306-R.
Interpretive Summary: Native fermentations are of increasing interest to Washington and US winemakers and wine consumers. This, and environmental impact concerns, warrant the exploration of biological control as an alternative to chemical fungicides. We have found that seven native or indigenous yeasts associated with Washington-grown wine grapes have the ability to control Washington isolates of the fungal pathogen causing Botrytis bunch rot of grapes. As the yeast strains showed partial to complete resistance to the commonly-used commercial fungicides Luna Privilege, Pristine, Procure and Vivando, field deployment of the yeasts might complement or alleviate chemical fungicides.
Technical Abstract: Native fermentations are of increasing interest to Washington and US winemakers and consumers. This, and environmental impact concerns, warrant the exploration of biological control as an alternative to chemical fungicides. The objective of this study was to characterize the biological control activities of native yeasts against the bunch rot fungal pathogen Botrytis cinerea, using yeast strains and pathogen isolates obtained from grapes grown in the state of Washington. We quantified the ability of eleven yeast strains, representing Candida saitoana, Curvibasidium pallidicorallinum, Metschnikowia chrysoperlae, Metschnikowia aff. pulcherrima, Meyerozyma guilliermondii, Saccharomyces cerevisiae and Wickerhamomyces anomalus, to colonize ‘Thompson Seedless’ grape berries, inhibit the growth of the pathogen in vitro, and suppress Botrytis bunch rot disease symptoms on isolated berries. The yeast-like fungus Aureobasidium pullulans var. pullulans was also included based on its described biocontrol activity against B. cinerea of apple. All yeast strains rapidly multiplied on grapes berries as early as two days after inoculation. Eight B. cinerea isolates used in this study were virulent on isolated berries; a ninth isolate that was much less virulent was provisionally identified as B. prunorum in a multi-locus sequence analysis. Bunch rot suppression of B. cinerea isolates 111bb, 207a, 207cb and 407cb occurred on berries treated with A. pullulans P01A006, Met. chrysoperlae P34A004, P40A002, Met. pulcherrima P01A016, P01C004, Mey. guilliermondii P34D003, and S. cerevisiae HNN11516. Berry inhibition was observed in more of the interactions compared to inhibition observed in vitro, indicating that niche competition was a more likely mechanism of control than antibiosis in planta. Metabolic profiling of yeast strains and B. cinerea isolates using Biolog YT plates supported this observation, and revealed seven distinct metabolic groups. Furthermore, the yeast strains showed partial to complete resistance to the commonly used commercial fungicides Luna Privilege, Pristine, Procure and Vivando. These findings have implications for field deployment of native Washington yeasts against B. cinerea.