山东省小麦禾谷孢囊线虫rDNA-ITS序列特征和基于ISSR的遗传多样性分析

小麦孢囊线虫病(CCN,Heterodera avenae)已成为山东省小麦生产上的一种重要病害,研究CCN群体间和群体内的遗传多样性可以为其综合防治提供理论依据。本实验研究了山东省17地市34个群体的r DNA-ITS区,并采用ISSR分子标记技术对其中10个地市的27个种群做了遗传多样性分析。结果表明,在r DNA-ITS系统发育树中,山东省34个小麦孢囊线虫群体与H.pratensis、H.australis及中国H.avenae群体亲缘关系较近。3个ISSR引物共扩增出31条条带,多态性条带百分率(PPB)为100%。菏泽、潍坊、烟台群体遗传多样性较高,枣庄、威海、淄博、滨州群体遗传多样性相对较低。M antel检测和聚类结果表明,群体间的遗传分化与地理距离并无显著的相关性,AM OVA分析结果显示,在总的遗传变异中17.7%的变异发生在群体间,82.3%的变异发生在群体内。研究结果显示山东省H.avenae具有较高的遗传多样性,且群体间已发生了一定程度的遗传分化。

rDNA-ITS sequence characterization and genetic diversity based on ISSR of cereal cyst nematode on wheat from Shandong Province

The cereal cyst nematode (CCN, Heterodera avenae) has been one of the important plant disease on wheat production in Shandong Province. Genetic diversity among and within CCN groups should be analyzed in order to provide theoretical basis for the integrated control. ITS region of ribosomal DNA was amplified from 34 populations in 17 cities of Shandong Province and ISSR was used to analyze the genetic diversity from 27 CCN populations in 10 cities of Shandong Province. The results of ITS sequences analysis showed that the 34 populations,H. pratensis,H. australis and H. avenae from China were clustered in the same group, showing high homology level in evolution. A total of 31 bands were detected with 3 ISSR primers, and the percentage of polymorphic bands (PPB) was 100%. The genetic diversity of Heze, Weifang and Yantai groups was higher and the diversity of Zaozhuang, Weihai, Zibo and Binzhou groups was lower compared to other populations. Mantel test indicated that there were no significant correlation between genetic distance and geographical distance. Analysis of AMOVA demonstrated that the inter-group component accounted for 17.7% of the total variation, while the inner-group component accounted for 82.3%. The result implied that the genetic diversity of H.avenae was relatively high in Shandong Province and there was genetic differentiation of some extent among groups.