葡萄伤流液中内生菌分离鉴定与抗病功能分析

为探究葡萄树液中内生菌的种类,对‘白罗莎里奥’葡萄伤流液中的内生菌进行分离纯化,得到4株普遍存在的有益菌株,根据形态特征、生理生化特性及16S rDNA序列同源性对其进行鉴定,并针对葡萄灰霉病病原菌进行抑菌测试。结果表明,4种内生菌分别为粘红酵母菌、隐球菌、水拉恩式菌、变形斑沙雷菌;平板抑菌试验显示,隐球菌、水拉恩式菌、变形斑沙雷菌均对灰霉病菌有一定的拮抗作用。对葡萄果粒的病菌侵染试验表明,隐球菌、水拉恩式菌、变形斑沙雷菌均能使果粒失水速率降低、灰霉病病斑缩小,抗菌物质类黄酮、总酚以及SOD、CAT、POD、PPO活性升高,灰霉病抗病相关基因VvHSF和VvDR下调,VvPR17、VvDW、VvChi和VvWRKY上调,且上调程度与抗病能力呈正相关,进一步表明了隐球菌、水拉恩式菌、变形斑沙雷菌对灰霉病菌有一定的抑制作用,在葡萄灰霉病防治中具有良好的应用潜力。

Isolation and Identification of Endophytes from Grape Bleeding Sap and Their Disease Resistance Function Analysis

In order to explore the roles of grape endophytes played in grey mould resistance，four universal endophyte strains（Rhodotorula mucilaginosa，Cryptococcus，Rahnella aquatilis and Serratia proteamaculans）were closely related，but far from Rhodotorula mucilaginosa and Cryptococcus）were isolated and purified from grape bleeding sap. Morphological observation，physiological characterization and 16S rDNA sequence analysis suggested Rahnella aquatilis and Serratia proteamaculans were closely related，but far from Rhodotorula mucilaginosa and Cryptococcus. In vitro antibacterial effects of the isolated endophytes were tested via plate co-cultivation and grape berry co-infection of both grey mould and the individual endophyte. The results indicated strong inhibition of grey mould’s growth by Cryptococcus，Rahnella aquatilis and Serratia proteamaculans. In addition，berries co-infected with Botrytis cinera and the endophyte showed reduced rate of water loss，increased anti-disease metabolites （flavonoids and total phenols）and the increment activities of SOD，CAT，POD，and PPO，together with the increased expression of disease resistant genes VvPR17，VvDW，VvChi and VvWRKY. These shed lights on the pathways endophytes participating in Botrytis cinera resistance. These results are of practical interest for improving grapevine resistance to grey mould.