小麦纹枯病菌核糖体基因内转录区序列比较

 对7个从江苏省小麦纹枯病样本分离到的丝核菌菌株,进行形态学鉴定、融合群分类和致病性测定,提取病菌的DNA,采用通用引物ITS1(TCC GTA GGT GAA CCT GCG G)和ITS4(TCC TCC GCT TAT TGA TAT GC),扩增病菌的rDNA内转录区(ITS),并对扩增产物进行了测序.用这些序列在NCBI中进行BLAST分析,得到与这些菌株亲缘关系最近的菌株序列,并明确了这些菌株的分类地位.对以上的菌株序列进行Alignment分析,结果表明,病菌的5.8S rDNA序列高度保守,而ITS区的可变性则相对较高,在双核和多核丝核菌、双核丝核菌CAG1融合群和非CAG1融合群菌株间存在差异,可用于反映菌株间的进化关系和双核丝核菌种下分类.

Comparison of Wheat sharp spot pathogenic isolates based on the internal transcribed spacer sequence

Seven Rhizoctonia isolates collected from different ecological origins in Jiangsu province were classified into CAG1,non-CAG1 of binuclear Rhizoctonia and AG-2 of R. solani by using anastomosis reactions and pathogenic potential. The internal transcribed spacer (ITS) region of the ribosomal DNA from these 7 isolates were amplified using universal prmers ITS1 (TCC GTA GGT GAA CCT GCG G) and ITS4 (TCC TCC GCT TAT TGA TAT GC). Sequence comparison revealed that 5.8S rDNA sequence was highly conserved,whereas the ITS rDNA sequence was variable among AG-2 isolate of R. solani ,CAG1 and non-CAG1 isolates of binucleate Rhizoctonia . These results suggest that sequence analysis of ITS rDNA regions may be a valuable tool for identifying pathogens of Wheat sharp eyespot.