引起马铃薯病害的丝核菌遗传多样性及其致病因子研究

Stem canker and black scurf of potato (Solanum tuberosum L.) caused by Rhizoctonia spp. is an important disease, which affects potato yield and quality devastatingly. Rhizoctonia solani isolates including anastomosis group (AG)-1, AG-2, AG-3, AG-4, AG-5, and AG-11 have been confirmed to be pathogenic on potato in China. Some binucleate Rhizoctonia isolates belonging to AG-A, AG-F, AG-G, AG-K, AG-U and AG-W were also reported to cause symptoms on potato crops. Rhizoctonia solani isolates including AG-7, AG-8, AG-9, AG-10 and binucleate Rhizoctonia AG-R were not found in China, which were documented abroad. Among these AGs, AG-3 (approximately 70%) is the dominant Rhizoctonia. Systemic study on binucleate Rhizoctonia isolates causing potato diseases were first reported by us internationally. However, no reports related to researching the genetic diversity of Rhizoctonia spp. infecting potato were published in China. Potato samples of underground stems with the symptom of stem canker and tubers with black scurf will be continuously collected from the potato growing areas all over the China for isolating Rhizoctonia spp.. Combined with morphological and molecular biological methods established in our publications before, the anastomosis groups (AGs) of Rhizoctonia isolates will be identified. Molecular biology methods, such as SSR and PCR-RFLP will be used to understand the distribution of multinucleate Rhizoctonia AG-3 among different geographical origins and the relationship between geographical origins and genetic diversity of AG-3 which can cause disease on potato in China. The results of this research will be expected to offer theoretical basis and technical support for allocating and transporting seed tubers, selecting rotation crops, and controlling the diseases efficiently.

由丝核菌引起的马铃薯茎溃疡病和黑痣病，严重影响马铃薯的产量和品质。申请人前期研究已明确立枯丝核菌AG-1~AG-5和AG-11以及双核丝核菌AG-A、AG-F、AG-G、AG-K、AG-U和AG-W可引起马铃薯病害；其中AG-3为优势融合群，约占70%。关于双核丝核菌的系统研究为国际上首次报道，但未发现国外已报道的立枯丝核菌AG-7~AG-10和双核丝核菌AG-R。迄今为止，我国尚未见引起马铃薯病害的丝核菌遗传多样性的研究报道。本研究继续采集我国马铃薯产区表现茎溃疡病和黑痣病症状的样品进行丝核菌的分离和纯化，并采用已建立的鉴定方法明确其融合群；同时采用SSR、PCR-RFLP等方法分析立枯丝核菌AG-3的遗传多样性，以明确其与地理来源之间的关系。研究结果将为我国马铃薯种薯的合理调运、轮作作物的选择以及病害的有效防治提供理论依据和技术指导。