Jiang Jr-Hau, Tam Si-Loi, Toda Takeshi, Chen Lung-Chung
Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan.
Faculty of Bioresource Science, Akita Prefectural University, Shimo-shinjo, Akita 010-0195, Japan.
Plant Dis. 2016 Jan;100(1):85-91. doi: 10.1094/PDIS-06-14-0597-RE. Epub 2015 Oct 27.
Inoculation of hypovirulent Rhizoctonia spp. has been recognized as an effective strategy for protecting plants against damping-off caused by pathogenic Rhizoctonia spp. In this study, endomycorrhizal Rhizoctonia spp. isolated from fungal pelotons in orchid plants were used for controlling Rhizoctonia damping-off of Chinese mustard. According to phylogenetic analysis and anastomosis group (AG) determination, the virulence of three isolates of multinucleate Rhizoctonia solani in AG-6; eight isolates of binucleate Rhizoctonia in AG-A, AG-B, AG-G, AG-P, and AG-R; and two isolates of binucleate R. repens were evaluated using test plants. All isolates, except that in AG-R, caused low disease severity in 10-day-old radish (0.10 to 0.61), cucumber (0.28 to 0.54), and Chinese mustard (0.18 to 0.65). By contrast, pathogenic isolates in AG-4 killed almost all test plants with symptoms of collapsed hypocotyl and wilted leaves (0.88 to 0.96). Of the 13 endomycorrhizal Rhizoctonia isolates assessed, AG-P isolates Cno10-3 and CalS1-2 provided 91 and 100% protection, respectively, against R. solani AG-4 in 26-day-old Chinese mustard. This study revealed that endomycorrhizal Rhizoctonia spp. in orchid have the potential to biologically control damping-off of Chinese mustard.
接种弱毒丝核菌已被认为是保护植物免受致病性丝核菌引起的猝倒病侵害的有效策略。在本研究中，从兰花植物真菌菌丝球中分离得到的内生菌根丝核菌被用于防治芥菜的丝核菌猝倒病。根据系统发育分析和融合群（AG）测定，使用试验植物对AG-6中多核立枯丝核菌的3个分离株、AG-A、AG-B、AG-G、AG-P和AG-R中双核立枯丝核菌的8个分离株以及双核匐柄霉的2个分离株的毒力进行了评估。除AG-R中的分离株外，所有分离株在10日龄萝卜（病情指数0.10至0.61）、黄瓜（病情指数0.28至0.54）和芥菜（病情指数0.18至0.65）上引起的病害严重程度较低。相比之下，AG-4中的致病分离株使几乎所有试验植物出现下胚轴萎蔫和叶片枯萎症状（病情指数0.88至0.96）。在评估的13个内生菌根丝核菌分离株中，AG-P分离株Cno10-3和CalS1-2在26日龄芥菜中对立枯丝核菌AG-4分别提供了91%和100%的保护。本研究表明，兰花中的内生菌根丝核菌具有生物防治芥菜猝倒病的潜力。
