拟禾本科根结线虫形态和分子鉴定

Morphological and molecular identification of Meloidogyne graminicola

在浙江杭州富阳区中国水稻研究所试验田水稻根际土壤中发现了大量根结线虫2龄幼虫和少量雄虫。2龄幼虫的形态学特征与已报道的拟禾本科根结线虫(Meloidogyne graminicola)基本一致。进一步通过对核糖体DNA(rDNA)18S、28S和ITS基因,以及线粒体COⅠ基因进行扩增和测序,并在Genbank中与已登录的拟禾本科根结线虫序列比对,发现其相似度高达99%～100%。在Genbank中登录其序列并构建系统进化树后,发现rDNA ITS和线粒体COⅠ可以作为快速鉴定拟禾本科根结线虫的基因,能将其与其近似种完全区分。

A large number of second-stage juveniles （J2） and a few males of Meloidogyne sp. were found in the rhizosphere soil of rice experimental plots in the China National Rice Research Institute,Fuyang District,Hangzhou City,Zhejiang Province. The morphological characteristics of the J2 were basically consistent with the reported Meloidogyne graminicola（Golden and Birchfield,1965 ）. The sequences of ribosomal DNA （rDNA） 18S region,28S region,ITS region,and mitochondrial cytochrome coxidase Ⅰ （CO Ⅰ） genes had a high genetic similarity （99%-100%） with the relevant sequences of M. graminicola in Gen- bank. The sequences of M. graminicola were submitted in Genbank,and phylogenetic tree based on rDNA and mitochondrial CO I was constructed. It was found that the rDNA ITS region and the mitochondrial CO Ⅰ region genes can be used as a rapid identification of the M. graminicola,which can be completely distinguished from its related species.