鸢尾种苗中截获的草莓滑刃线虫形态和分子鉴定

草莓滑刃线虫是一种重要的叶和芽寄生线虫,可侵染多种重要花卉、经济作物,被列入我国检疫性有害生物名录。目前,草莓滑刃线虫的鉴定以形态学鉴定为主,但一线口岸常分离不到雌虫,鉴定困难。本研究采用形态特征和分子特征相结合的方法对草莓滑刃线虫进行鉴定:对鸢尾种苗中截获的滑刃属线虫群体雌虫、雄虫进行形态观察和形态测计并与已报道文献进行比较;PCR扩增该群体的rDNA-ITS区并测序,构建基于ITS序列的系统发育进化树;采用草莓滑刃线虫特异引物对该群体DNA样本进行扩增。结果表明:该群体与草莓滑刃线虫俄罗斯种群的测量值相接近;系统进化关系分析显示,该群体与NCBI公布的草莓滑刃线虫均处于同一进化支;采用草莓滑刃线虫特异引物PCR扩增可产生片段大小为169 bp的目的条带。

Morphological and molecular identification of Aphelenchoides fragariae intercepted in seedlings of iris bulbs

Aphelenchoides fragariae is a kind of important leaf and bud parasitic nematode, which can infect a variety of important flowers and cash crops. It was listed as a quarantine pest in China. At present, the identification of A.fragariae is mainly based on morphological characters, but the females are often unobtainable in the ports, which makes the morphological identification difficult. In this study, we identified A.fragariae through the combination of morphological and molecular features: the morphology of females and males were observed and morphometrics was conducted for Aphelenchoides spp. in iris bulbs; the ITS regions of ribosomal DNA were amplified and the PCR products were sequenced, and then a phylogenetic tree was constructed based on the ITS sequences. In addition, the species-specific primers were used to validate the identification. The results showed that the Aphelenchoides spp. were similar to those previously described based on morphological and morphometric comparisons. Phylogenetic analyses revealed that the Aphelenchoides spp. were grouped with A.fragariae from different origins. A single band of 169bp was amplified using species-specific primers.