中国马铃薯主产区晚疫病菌遗传变异研究

发布时间：2018-05-27 00:15

  本文选题：致病疫霉 + 群体遗传　； 参考：《内蒙古大学》2017年硕士论文

【摘要】：马铃薯晚疫病是由致病疫霉[Phytophthora infestans(Mont.)de Bary]引起的马铃薯上最严重的病害之一。了解马铃薯晚疫病菌群体遗传结构的组成情况,对明确病害发生及流行规律具有重要意义,为马铃薯晚疫病的有效防控提供重要理论依据。本研究对中国马铃薯主产区采集的晚疫病病原菌致病疫霉菌样品分离纯化,从交配型、甲霜灵抗性和SSR分子标记三个方面,描述群体结构特征,分析群体多样性。对2015年采自云南、四川、贵州、湖北、内蒙古、黑龙江共六个主产区的样本进行分离纯化,分离到213株P.infestans菌株。同时,利用FTA采样卡采集91株样品。利用皿内对峙法对213株菌株的交配型进行检测,结果表明内蒙古地区菌株均是A1交配型,其他地区菌株以A2交配型为主,其中贵州、黑龙江、四川的晚疫病菌中A1、A2两种交配型同时存在。在甲霜灵抗性检测中,甲霜灵高抗菌株占25.82%、中抗菌株占72.77%、敏感菌株占1.41%。中度抗性和高度抗性菌株在所有地区所占比例都超过80.00%,其中内蒙古地区无敏感性菌株,高度抗性菌株超过80.00%。选用4种荧光标记的12对SSR引物对213株样品基因型进行鉴定,共鉴定出73个不同的基因型,北方地区以MLG 50、MLG 71基因型为主;南方地区无明显优势型。仅有少量基因型同时出现在南北方,如MLG 20基因型出现在黑龙江和湖北,MLG 50出现在云南和黑龙江,MLG 61出现在云南、四川和黑龙江。基于SSR多态性的聚类分析结果显示,南方和北方晚疫病群体菌株间的亲缘关系较远,遗传背景存在显著差异。基于SSR测序数据,进行主成分分析(PCA)和分子方差分析(AMOVA)。分子方差分析结果表明不同省份间晚疫病菌基因型差异显著,变异主要来源于省份间而非省份内部。主成分分析结果显示所有菌种样本分为三个类群(Group)。Group Ⅰ主要包含湖北地区样品,GroupⅡ主要包含内蒙古地区样品,GroupⅢ主要包括云南、四川、贵州地区样品。以上结果表明菌种类群与地域来源相关。
[Abstract]:Potato late blight is one of the most serious potato diseases caused by Phytophthora infestans [Phytophthora infestans(Mont.)de Bary]. Understanding the composition of population genetic structure of potato late blight fungus is of great significance to clarify the occurrence and epidemic law of potato late blight and provide important theoretical basis for the effective prevention and control of potato late blight. In this study, samples of Phytophthora infestans collected from the main potato producing areas in China were isolated and purified. The population structure and diversity were described and analyzed from three aspects: mating type, metalaxyl resistance and SSR molecular markers. Two hundred and thirteen strains of P.infestans were isolated from six main producing regions of Yunnan, Sichuan, Guizhou, Hubei, Inner Mongolia and Heilongjiang in 2015. At the same time, 91 samples were collected by FTA sampling card. The mating type of 213 strains was detected by in-dish confrontation method. The results showed that all the strains in Inner Mongolia were A1 mating type, while the other strains were A2 mating type, including Guizhou, Heilongjiang, Heilongjiang. There are two mating types of A _ 1 A _ 2 in late blight bacteria in Sichuan. In the detection of metalaxyl resistance, the percentage of high resistant strains was 25.82, the antibacterial strain was 72.77 and the sensitive strain was 1.41%. The proportion of moderately resistant and highly resistant strains in all regions was more than 80.00.Among them, there were no sensitive strains in Inner Mongolia region, and more than 80.00g strains with high resistance strains in Inner Mongolia. A total of 73 different genotypes were identified by using 12 pairs of SSR primers with four fluorescent markers. The dominant genotype of MLG 50 MLG71 was found in the northern region, but there was no obvious dominant genotype in the southern region. Only a few genotypes appeared in the south and north, such as the MLG 20 genotype appeared in Heilongjiang and Hubei Province, the MLG50 appeared in Yunnan and Heilongjiang, Sichuan and Heilongjiang appeared in Yunnan, Sichuan and Heilongjiang. The results of cluster analysis based on SSR polymorphism showed that the relationship between the strains of late blight in the south and the north was far away, and the genetic background was significantly different. Based on SSR sequencing data, principal component analysis (PCA) and molecular variance analysis (AMOV A) were performed. The results of molecular variance analysis showed that the genotypes of late blight bacteria were significantly different among different provinces, and the variation was mainly from different provinces rather than from within provinces. The results of principal component analysis showed that all the samples were divided into three groups, Group.Group 鈪，

本文编号：1939553