美国多花黑麦草种子中致死粒线虫的检疫鉴定

Identification of Anguina funesta in Lolium multiflorum from the United States

致死粒线虫(Anguina funesta)是具有重要经济意义的粒线虫,被多国列入检疫性有害生物名录。2021年,上海口岸从来自美国的多花黑麦草(Lolium multiflorum)种子中截获一种粒线虫属线虫,但在该样品中仅分离得到幼虫,无法准确鉴定。本研究运用形态学与分子生物学相结合的方法对分离得到的幼虫进行鉴定。采用28S通用引物扩增该线虫序列,测序获得742 bp的序列,与GenBank中登录的致死粒线虫相似性达100%;采用ITS通用引物对ITS区扩增并测序,获得778 bp的序列,与GenBank中登录的致死粒线虫相似性达99.86%~100%。基于28S及ITS区序列构建的系统进化树均显示,该线虫与致死粒线虫位于同一进化枝上。综合形态学特征及分子鉴定结果,将该群体鉴定为致死粒线虫。这是我国口岸首次报道截获该线虫,本研究将为口岸检疫部门鉴定该线虫提供技术参考。

Anguina funesta is an important economic species of Anguina listed as a quarantine pest by several countries.In 2021,a population of Anguina sp.from the seeds of Lolium multiflorum from the United States was intercepted at the port of Shanghai.Only the larvae were isolated from the sample,and accurate identification could not be performed.A combination of morphological and molecular methods for detection was used.The nematode sequence was amplified by 28S universal primers and obtained a 742 bp sequence,which was 100% similar to A.funesta registered in GenBank.The internal transcribed spacer(ITS)region was amplified and sequenced to obtain a 778 bp sequence of 99.86%~100%,similar to A.funesta in GenBank.The phylogenetic tree based on 28S and ITS sequences was constructed.The results revealed that the sample clustered with A.funesta in GenBank.Based on morphological and molecular biology characteristics,the Anguina spp.was identified as A.funesta.The Shanghai port is the first in China to intercept A.funesta.