【作者】 刘敏；

【导师】 黄俊斌；

【作者基本信息】 华中农业大学 ， 植物病理学， 2010， 硕士

【摘要】 大豆疫霉根腐病是由大豆疫霉引起的一种重要的大豆病害,在大豆主产区造成严重的经济损失。由于大豆疫霉菌毒力变异快,给抗病品种的选育和布局带来困难。本研究主要包括以下方面：1.对来源于6个不同地区的30株大豆疫霉菌进行毒力分析,将结果与目前已经报道的生理小种的反应型进行比较,30个菌株产生30个新的毒力型。供试菌株的地理来源与毒力类型的相关性不明显,不同地区间、同一地区内不同的大豆疫霉毒力分化显著,不同地区的优势毒力类型存在差异。大豆疫霉菌的毒力结构非常复杂。2.用18对SSR引物对30个大豆疫霉菌株进行遗传分析。18对引物在30个大豆疫霉菌菌株中一共扩增得到85个等位变异,平均为4.27个。各不同地区Shannon’s多样性指数各组大小顺序为：黑龙江>安徽>新疆>河南>福建>美国。安徽和黑龙江的菌株遗传距离最近,美国与福建的菌株遗传距离最远。引物PSG113、PSG133、PSG125多态性较好,可以将30个菌株完全区分开,对这3个引物的扩增条带进行统计分析,其聚类结果与毒力聚类结果具有较大的一致性。3.采用13个ISSR引物对30株大豆疫霉菌进行遗传多样性分析。13个ISSR引物在30份菌株中总共扩增出79个等位变异,平均为6.08个。Shannon’s多样性指数各组大小顺序为：河南>黑龙江>新疆>福建>安徽>美国。新疆和黑龙江的菌株遗传距离最近,美国与福建的菌株遗传距离最远。美国的菌株与其他地区的菌株遗传距离较远。4.21个RAPD引物在30份菌株中总共扩增出78个等位变异,平均为3.71个。6个不同地理来源供试群体遗传多样性比较丰富,Shannon’s多样性指数各组大小顺序为：黑龙江>河南>新疆>安徽>福建>美国。河南和新疆遗传距离最近,美国与新疆、美国与福建的菌株遗传距离较远。美国的菌株与其他地区的菌株遗传距离较远。5.对这3种分子标记技术所得的遗传相似系数矩阵的相关性进行分析,2种显性标记ISSR与RAPD的相关性系数为0.543,呈相关；SSR与ISSR的相关性系数为0.243,不相关；SSR与RAPD的相关性系数为0.393,呈弱相关。3种分子标记揭示的遗传多样性水平存在差异,两两之间的相关性不同,可能与不同的分子标记揭示不同的遗传位点、选用的引物有关。更多还原

【Abstract】 Soybean Phytophthora root rot(PRR) caused by Phytophthora sojae is a devastating diseases of soybean.PRR causes serious losses in soybean production areas.Because of the rapid pathogenic variability of Phytophthora sojae,control this diseases through breeding and make good use of resistant cultivaters has become difficult Five main aspects of this study as followed:1. The virulence types of 30 P. sojae isolates from 6 different areas were identified,the results were compared with the virulence types of reported races,the virulence type of thses 30 isolates are all new types.there is no obvious correlation between the origion of the isolates and the virulence type.Isolates from different areas and different isolates from the same area show great virulence difference.Main virulence types varies in different areas. Virulence composition of P. sojae population is complex.2.18 SSR markers were used to assess the genetic diversity of 30 P. sojae isolates.85 alleles were detected in 30 P. sojae isolates by 18 SSR primers, with an average of 4.27. The order of Shannon’s Information index of different areas is:Heilongjiang> Anhui> Xinjiang> Henan> Fujian> America. The populations from Anhui and Heilongjiang are closer than others, and the population from America and Fujian are moer distant than others.The 30 isolates can be efficiently distinguished by primer PSG113、PSG133、PSG125. The data were analyzed by NTSYS-PC 2.1 software and the result is quite similar to virulence analyze.3.13 SSR markers were used to assess the genetic diversity of 30 P. sojae isolates.79 alleles were detected in 30 P. sojae isolates by 18 SSR primers, with an average of 6.08. The order of Shannon’s Information index of different areas is: Henan>Heilongjian>Xinjiang>Fujian>Anhui>America. The populations from Xinjian and Heilongjiang are closer than others, and the population from America and Fujian are moer distant than others.Population from America show less similarity to other groups.4.21 RAPD markers were used to assess the genetic diversity of 30 P. sojae isolates.78 alleles were detected in 30 P. sojae isolates by 21 RAPD primers, with an average of 3.71. Populations from 6 areas show high levels of polymorphism.The order of Shannon’s Information index of different areas is:Heilongjiang>Henan>Xinjiang>Anhui>Fujian>America.The populations from Xinjian and Henan are closer than others, and the population from America and Fujian、America and Xinjian are moer distant than others.Population from America show less similarity to other groups. The genetic diversity levels of populations from Beijing and Shandong were higher than those of other regions.5. The genetic similarity coefficient obtained by 3 approaches was analyzed,two dominate makers system(ISSR and RAPD)show the best correspondence(0.543);There is weak correspondence between SSR and RAPD(0.393);Maker system (SSR and ISSR)show no correspondence(0.243).The genetic diversity levels obtained by 3 approches differs,may be different maker system revals different genetic site、and the use of different maker is the reason.更多还原