黄淮海地区夏玉米纹枯病菌的融合群鉴定

从黄淮海地区采集玉米纹枯病标样250余份,分离得到176个丝核菌菌株。融合群测定及5.8SrDNA-ITS区序列分析结果表明,这些菌株分别属于多核丝核菌的AG1-IA、AG1-IB、AG4-HG-I、AG-5、WAG-Z融合群及双核丝核菌的AG-A、AG-Ba融合群。其中AG1-IA是优势融合群,占分离菌株总数的64.20%,其次是AG-Ba,占12.50%,再依次分别是WAG-Z(10.23%)、AGI-IB(5.11%)、AG-4-HG-I(3.98%)、AG-5(2.27%)和AG-A(1.70%)。其中AG-Ba融合群是国内首次在玉米上分离得到。从各融合群中选取代表性的菌株进行5.8S rDNA-ITS区序列分析结果表明,隶属不同融合群或亚群的菌株其5.8S rDNA-ITS区序列存在较大的差异,而相同融合群(或亚群)不同菌株之间其序列的一致性可高达97%-100%。

The anastomosis groups of the corn sheath blight pathogen Rhizoctonia spp. in Huanghuai Plain and Haihe Plain of China

One hundred and seventy-six isolates were obtained from corn sheath blight samples in Huanghuai Plain and Haihe Plain (including Shandong, Henan, Hebei Provinces and Northern regions of Jiangsu Province) of China. Anastomosis group identification and 5.8S rDNA-internal transcribed spacer (ITS) sequence analysis showed that the isolates belonged to multinucleate Rhizoctonia AG1-IA, AG1-IB, AG4-HG-I, AG-5 and WAG-Z and binucleate Rhizoctonia AG-A and AG-Ba. Of these, AG-1-IA was the major anastomosis group(AG)(64.20% of total isolates), followed by AG-Ba (12.50%), WAG-Z (10.23%), AG1-IB (5.11%), AG4-HG-I (3.98%), AG-5 (2.27%) and AG-A (1.70%). AG-Ba was isolated for the first time from maize inChina. 5.8S rDNA-ITS sequence analysis showed that the isolates could be distinctly separated based on their AG types. The isolates belonging to the same AG (or sub-AG) showed 97%-100% sequence identity.