腥黑粉菌属3种检疫性真菌rDNA-IGS区的扩增及其序列分析

Amplification and sequence analysis of the rDNA intergenic spacer(rDNA-IGS) from three Tilletia species

为了发掘腥黑粉菌属检疫性真菌的特异性分子标记，本研究对来自不同地区的3种检疫性腥黑粉菌：小麦矮腥黑穗病菌（Tilletia controversa）、小麦网腥黑穗病菌（T.caries）和小麦光腥黑穗病菌（T.foetida）的IGS区进行了PCR扩增和序列测定，其IGS1和IGS2区的长度分别为1511～1513bp和1196-1199bp，G＋C含量分别为52．6％和49．0％。用DNAMAN软件进行比对分析发现，这3种真菌在IGS1区存在不同程度的多态性，而IGS2区的保守性很强，没有特异性的碱基位点存在。依据它们在IGS1区序列的差异，设计了一对特异性引物，可用于T.foetida的分子检测，这是首次利用分子生物学技术对该菌进行鉴定。

In order to find specific molecular markers for detecting the genus Tilletia at species level, the rDNA-IGSs of different strains of Tilletia controversa, T. foetida and T. caries were amplified and sequenced. The nucleotide sequences of IGS1 and IGS2 varied in length from 1 511 to 1 513 bp and 1 196 to 1 199 bp with average G ＋ C content 52.6% and 49.0%, respectively. The results of sequence alignment analysis using DNAMAN indicated that the IGS1 was more variable than the IGS2 among the three species. Based on the sequence differences in IGS1, a pair of primers was designed and could be used to detect T. foetida specifically by PCR amplification. This is the first report about identification of T. foetida by molecular techniques.