河南省玉米田根腐线虫三个病样品的病原种类鉴定

Identification of pathogenic species of three root-lesion nematodes samples from corn fields in Henan Province

短体属线虫(Pratylenchus Flipjev,1936)又称根腐线虫,是一类重要的迁移性植物内寄生线虫,世界范围内分布广泛且危害性大,在我国多个省份皆有发生危害。本文采用改进的贝尔曼漏斗法从河南省商丘市、荥阳市和洛阳市的3个玉米土壤样品中分离出根腐线虫,利用光学显微镜进行形态学鉴定,基于rDNA的ITS和28S D2-D3区序列以及mtDNA-COI序列对供试根腐线虫进行了分子鉴定。形态学和分子生物学鉴定结果均表明来源于商丘样品的SY-1和SY-2种群分别为咖啡短体线虫(P.coffeae)和斯克里布纳短体线虫(P.scribneri);来源于荥阳样品的XY-1种群和洛阳样品的XC-250种群,均为斯克里布纳短体线虫(P.scribneri)。基于rDNA-ITS、28S D2-D3区和mtDNA-COI序列构建的系统进化树结果与已知鉴定结果相一致,本研究鉴定的短体线虫种类,分别单独聚类在各自分支。本研究明确了河南省玉米田3个病样品的病原种类,发现采自商丘的病样品存在两种根腐线虫复合侵染的现象,且3个病样品均发现斯克里布纳短体线虫(P.scribneri)的存在,研究结果为玉米根腐线虫病害的识别与防控提供了一定的科学依据。

Pratylenchus spp.,also known as root-lesion nematodes,are a kind of important migratory plant parasitic nematodes,which are widely distributed and harmful in the world.Root-lesion nematodes are also distributed in many provinces of China.In this study,the root lesion nematodes were extracted from corn soil samples using the modified Baermann funnel method,which were collected from corn fields in Shangqiu,Xingyang and Luoyang cities of Henan province.Morphological identification was carried out by optical microscope,and molecular identification was carried out based on rDNA sequences of ITS,rDNA 28 S D2-D3 regions and mtDNA-COI sequences of root-lesion nematodes.The morphological and molecular identification results showed that SY-1 and SY-2 populations collected from Shangqiu city were P.coffeae and P.scribneri,respectively.Whereas XY-1 population collected from Xingyang city and XC-250 population collected from Luoyang city were identified as P.scribneri.The results of phylogenetic tree constructed based on rDNA sequences of ITS,28 S D2-D3 regions and mtDNA-COI sequences were consistent with the molecular identification,and the collected root-lesion nematode populations in this study were separately clustered in their respective clades.In this study,the pathogenic species of three samples collected from the maize fields in Henan province were identified.The complex infection phenomenon of two root-lesion nematodes was observed in the sample from Shangqiu city,and P.scribneri was found in all the three samples.The results provide scientific basis for the detection and control of maize root-lesion nematode diseases.