江苏省小麦纹枯病病原组成及其致病力研究

The Profile and Virulence of Wheat Sharp Eyespot Pathogens in Jiangsu

为了明确目前江苏省小麦纹枯病病原的组成和致病性,从江苏省13个市的65个县(市)采集到的小麦纹枯病典型症状病株上共分离到171株丝核菌,通过苏木精染色法观察,其中双核丝核菌169株,多核丝核菌2株。这些双核丝核菌分别属于不同的融合群,通过菌丝对峙培养,考马斯亮蓝染色观察,其中CAG 1群158株,占93.49%,其它融合群共11株,占6.51%。2株多核丝核菌能互相融合,PCR扩增病菌的内转录区并进行测序,B last分析结果表明,它们属于AG 2融合群。对这171个丝核菌菌株进行了室内3个小麦品种的致病力测定,结果表明,菌株间致病力强弱存在明显差异,双核丝核菌的致病力强度显著高于多核丝核菌,双核丝核菌间不同融合群菌株致病力无明显差异。不同来源的菌株间致病力有明显差异,以无锡、连云港、泰州地区菌株致病力最强,南通菌株最弱。

171 Rhizoctonia isolates were collected from different areas of Jiangsu province in 2001. The identification results showed, among these isolates 169 isolates were Rhizoctonia cerealis with percentage of 98.83 %, 2 isolates were Rhizoctonia solani. Among these R. cerealis isolates, 158 isolates were in CAG1 anastomosis group, 11 isolates were in other anastomosis group. The 2 isolates of R. solani were in AG2 anastomosis group based on blast of their ITS sequences. The pathogenicity of all isolates was evaluated with artificial inoculation method. The results showed that virulence of all these isolates was different significantly, the virulence of R. cerealis isolates was higher than that of R. solani isolates. No significant difference was observed among different anastomosis of R. cerealis. The virulence of isolates from 13 cities was significantly different. The virulence of isolates from Wuxi, Lianyungang, Taizhou was the highest, the virulence of isolates from Nantong were the lowest.