北方春玉米区长岭发垫刃线虫的分布及遗传多样性分析

Distribution and genetic diversity analysis of Trichotylenchus changlingensis in spring maize regions

为明确长岭发垫刃线虫(Trichotylenchus changlingensis)的分布,2018年对黑龙江、吉林、辽宁、河北、内蒙古、甘肃6省(自治区)118个地块的玉米根际土壤中长岭发垫刃线虫进行分离及鉴定,结果表明:在6个省(自治区)20个地块的土样中分离到该线虫,分离比例为17.0%。同时采用ISSR分子标记技术对分离到的20个种群进行遗传多样性分析。结果共筛选出16条引物,扩增出93条多态性条带,多态性比率为93.55%。基因分化系数(Gst)为0.4771,遗传变异的47.71%存在于种群间,52.29%存在于种群内。基因流(Nm)值为0.5479,说明所调查地区种群间存在基因流,基因流动较小,但种群间已发生一定程度的遗传分化。UPGMA聚类分析结果表明,这20个种群具有丰富的遗传多样性,但群体间的遗传关系远近与地理距离无显著相关性。

To determine the distribution of Trichotylenchus changlingensis in different geographical populations,in 2018,nematodes were isolated and identified from the rhizosphere soil of maize in 118 regions of Heilongjiang,Jilin,Liaoning,Hebei,Inner Mongolia and Gansu provinces(autonomous regions).The results showed that the nematodes were isolated from 20 soil samples in 6 provinces(autonomous regions)with isolation frequency of 17.0%.Sixteen highly polymorphic and reproducible ISSR primers were screened out and were used to amplify the 20 T.changlingensis isolates.A total of 93 polymorphic bands were obtained with a polymorphism ratio of 93.55%.The genetic differentiation coefficient(Gst)was 0.4771,indicating that the inter-group component accounted for 47.71%of the total variation,while the inner-group component accounted for 52.29%.The gene flow(Nm)was 0.5479 indicating that there was a less gene flow among different geographical populations.But there was genetic differentiation of some extent among groups.UPGMA cluster analysis showed that the T.changlingensis was rich in genetic diversity and there was no significant correlation between genetic distance and geographical distance.