Bustamante Marcelo I, Elfar Karina, Eskalen Akif
Department of Plant Pathology, University of California, Davis, CA 95616, USA.
Microorganisms. 2022 Oct 14;10(10):2035. doi: 10.3390/microorganisms10102035.
Grapevine trunk diseases (GTDs) are caused by multiple unrelated fungal pathogens, and their management remains difficult worldwide. Biocontrol is an attractive and sustainable strategy given the current need for a cleaner viticulture. In this study, twenty commercial vineyards were sampled across California to isolate endophytic and rhizospheric bacteria from different grapevine cultivars with the presence and absence of GTD symptoms. A collection of 1344 bacterial isolates were challenged in vitro against and , from which a subset of 172 isolates exerted inhibition levels of mycelial growth over 40%. Bacterial isolates were identified as ( 154), spp. ( 12), ( 2) and others that were later excluded ( 4). Representative isolates of , and were challenged against six other fungal pathogens responsible for GTDs. Mycelial inhibition levels were consistent across bacterial species, being slightly higher against slow-growing fungi than against Botryosphaeriaceae. Moreover, agar-diffusible metabolites of strongly inhibited the growth of and , at 1, 15, and 30% /. The agar-diffusible metabolites of and , however, caused lower inhibition levels against both pathogens, but their volatile organic compounds showed antifungal activity against both pathogens. These results suggest that , and constitute potential biocontrol agents (BCAs) against GTDs and their application in field conditions should be further evaluated.
葡萄树干病害（GTDs）由多种不相关的真菌病原体引起，在全球范围内其防治仍然困难。鉴于当前对更清洁葡萄栽培的需求，生物防治是一种有吸引力且可持续的策略。在本研究中，对加利福尼亚州的20个商业葡萄园进行了采样，以从有和没有GTD症状的不同葡萄品种中分离内生细菌和根际细菌。对1344株细菌分离株进行了体外抗 和 的测试，其中172株分离株对菌丝体生长的抑制水平超过40%。细菌分离株被鉴定为 （154株）、 属（12株）、 （2株）以及其他后来被排除的菌株（4株）。 、 和 的代表性分离株对其他六种导致GTDs的真菌病原体进行了测试。不同细菌物种的菌丝体抑制水平一致，对生长缓慢的真菌的抑制作用略高于对葡萄座腔菌科真菌的抑制作用。此外， 的琼脂可扩散代谢产物在1%、15%和30% 时强烈抑制 和 的生长。然而， 和 的琼脂可扩散代谢产物对两种病原体的抑制水平较低，但它们的挥发性有机化合物对两种病原体均表现出抗真菌活性。这些结果表明， 、 和 构成了针对GTDs的潜在生物防治剂（BCAs），应进一步评估它们在田间条件下的应用。
