【作者】 姚海燕；

【导师】 肖炎农； 朱振东；

【作者基本信息】 华中农业大学 ， 植物病理学， 2009， 硕士

【摘要】 由大豆疫霉菌（Phytophthora sojae）引起的大豆疫霉根腐病是严重影响大豆生产的病害之一。该病已在我国一些大豆主要产区发生和危害,在局部地区造成较大产量损失。由于其土居特性,只要条件适宜,大豆疫霉菌在大豆整个生育时期都能侵染大豆造成危害,导致早期大豆烂种、猝倒和中后期根、茎腐。虽然一些杀菌剂如甲霜灵、霜脲青、杀毒矾等对大豆疫霉菌有较好的抑制作用,但这些杀菌剂药效期有限,均不能有效控制病害的发生。实践证明,防治该病害唯一有效的方法是利用抗病品种。迄今为止,国内外已鉴定出15个抗疫霉根腐病基因,但这些基因在我国还没有得到充分的评价和利用。因此,为了控制大豆疫霉根腐病在我国的危害,必须发掘新的抗病基因。大豆品种早熟18是抗疫霉根腐病的有效抗原。本研究鉴定和分子标记早熟18的抗疫霉根腐病基因,以期为该品种的有效利用及分子辅助育种奠定基础。以感病大豆品种Williams与早熟18杂交建立F₂群体和F₃代进行抗大豆疫霉根腐病鉴定,x²检验表明,F₂代抗感分离比符合3∶1,F₃代纯合抗病、中间型、纯合感病分离比符合1∶2∶1,即抗感分离比符合3∶1。抗性遗传分析表明,早熟18对大豆疫霉菌抗性受一个显性单基因控制,该基因被定名为RpsZS18。用753对SSR引物对抗感亲本DNA和抗感池的DNA进行筛选,202对引物在亲本间扩增出多态性条带,亲本间多态性引物检出率为26.8%,有8对引物在亲本和抗感池扩出共显性标记,分别是CSSR45、Satt172、Sat₀69、Sat₁83、Satt274、Sat₁98、Sat₄15和Sat₂89。连锁分析表明RpsZS18位于大豆分子遗传连锁群D1b上的SSR标记Sat₀69和Sat₁83之间,与这两个标记的遗传距离分别为10.0 cM和8.3 cM。RpsZS18是D1b连锁群上鉴定的第一个抗疫霉根腐病基因,是一个新的抗病基因。更多还原

【Abstract】 Phytophthora root rot caused by Phytophthora sojae is one of the most important diseases in soybean throughout the world,which can influence the yield.Developoyment of resistant cultivars is the most effective method for controlling this disease.Up to date, 15 Phytophthora resistance genes（Rps gene）have been found,and most of them have been mapped by using molecular markers.Soybean cultivar Zaoshul8 has been identified as an effective source resistant to Phytophthora root rot of soybean.The objectives of this study were to identify and map the Phytophthora resistance gene in Zaoshu18 in order to facilitate its utilization and marker-assisted breeding.Zaoshu18 was crossed with susceptible cultivar Williams to develop mapping populations.The ratio of resistant to susceptible plants in F₂ popuation was 3:1,and The ratio of resistant,seragation and susceptible families in the F₃ lines was 1:2:1,these results indicated the resistance to Phytophthora sojae in Zaoshu18 was controlled by a dominant single gene.The resistance gene was temporarily designated RpsZS18.Zaoshu18 and Williams were crossed and the F₂ seperation population was obtained.753 pairs of SSR primer were screened,and 202 SSR markers were found to have the polymorphism between two parents.The rate of polymorphism of SSR markers was 26.80%.BSA（Bulked segregation analysis） method was used to screen the polymorphic primers.The order of eight co-dominant microsatellite markers linked to RpsZS18 was established as:CSSR45-Satt172-Sat-O69-RpsZS18-Sat-183-Satt274-Sat-198-Sat-415-Sat-289.Based on linkage analysis of SSR markers,RpsZS18 was located on soybean molecular linkage group（MLG） D1b between SSR markers Sat₀69 and Sat₁83 with genetic distances 10.0 cM and 8.3 cM,respectively.This is the first locus for Phytophthora resistance that has been identified on MLG D1b,so it should be novel resistance gene.更多还原