中国薯蓣干腐病的病原鉴定

Identification of the causal agent of dry rot disease of yam in China

在薯蓣发病块茎组织中分离到真菌菌株HSQM2005，经柯赫氏法则验证该菌为薯蓣致病菌。对菌株HSQM2005核糖体DNA内转录间隔区（internal transcribed spacer，ITS）进行序列分析，并结合其形态特征、培养性状将该菌鉴定为Penicillium sclerotigenum Yamamoto。该菌生长温度范围10～31℃，最适温度22～28℃；在pH2～12均能生长，最适pH为5～8。

A fungal strain HSQM2005 was isolated from the diseased tuber tissue of yam in Guangxi, China. The pathogenicity of the strain was confirmed by inoculation and re-isolation tests on the tubers of yam. The ITS se quence of rDNA from the strain was analyzed. The pathogenic strain HSQM2005 showed 100% homology in ITS se quence with that of Penicillium sclerotigenum Yamamoto retrieved from GenBank. The growth temperature of the strains varied from 10 ℃ to 31 ℃, and 22-28 ℃ was the most suitable temperatures for the growth of the patho gen. The pathogen could grow on media with pH values ranging from 2 to 12. The media with pH 5-8 were mos suitable for its growth. This is the first record on the occurrence of yam dry rot disease caused by P. sclerotigenunt in China. P. sclerotigenum is a new species recorded in China.