为研究5个水稻品种对美国稻瘟病小种IB-1、IE-1k和IG-1的抗性遗传,于2008―2009年在美国阿肯色大学潘布拉夫分校和水稻研究推广中心,用中国水稻品种特青和4个美国水稻品种Katy、Mars、LaGrue和Newbonnet组成完全双列杂交。一代、杂交二代和亲本在温室,用美国稻瘟病(Magnaporthegrisea)3个主要菌原小种IB-1、IE-1k和IG-1进行接种鉴定,进行完全双列杂交遗传分析研究。结果表明:特青抗所有的小种;Katy抗IB-1和IG-1,但感IE-1k;Mars抗IE-1k和IG-1,但感IB-1;LaGrue感所有小种;Newbonnet抗IG-1,但感IB-1和IE-1k。抗病品种特青与感病品种Newbonnet对小种IB-1,抗病品种特青与抗病品种Mars对IE-1k,抗病品种特青与抗病品种Katy,抗病品种特青与抗病品种Newbonnet对IG-1,其正反交二代抗病植株与感病植株的比例为63∶1,说明,这些抗病品种对相应的IB-1、IE-1k和IG-1分别存在3对独立遗传的显性抗病基因,出现重叠作用的遗传关系。抗病品种特青与抗病品种Katy,抗病品种特青与感病品种LaGrue,抗病品种Katy与感病品种Newbonnet对IB-1,抗病品种特青与感病品种Mars和感病品种Lagure,抗病品种Katy与感病品种Mars和感病品种Lagure对IG-1,其正反交杂交二代抗病植株与感病植株的分离比例符合15∶1的比例,说明,这些抗病品种对相应稻瘟病小种存在两对独立遗传的显性抗性基因,出现重叠作用的遗传关系。抗病品种Mars与感病品种Katy、感病品种Lagure和感病品种Newbonnet对IE-1k,其杂交一代表现感病,正反交杂交二代抗病植株和感病植株的分离符合7抗︰9感的比例,说明,品种Mars存在两对隐性抗病基因,感病品种Katy、Lagure和Newbonnet与抗病品种Mars的后代出现两对显性感病基因互补作用的遗传关系。抗病品种特青与感病品种Mars,抗病品种Katy与感病品种Mars及LaGrue对IB-1,抗病品种特青与感病品种Katy、LaGrue和Newbonnet对IE-1k,抗病品种Katy、Mars和Newbonnet与感病品种LaGrue对IG-1,其正反交二代的抗病植株与感病植株的比例为3︰1,说明,这些品种对IB-1、IE-1k和IG-1的抗性分别存在1对显隐性基因遗传关系。感病品种Mars、La-Grue、Newbonnet对IB-1和感病品种Katy、LaGrue、Newbonnet对IE-1k,其正反交二代全为感病植株,说明,这些感病品种分别对IB-1、IE-1k的感病基因是等位的。 In order to study the resistance inheritance of five rice cultivars to IB-1, IE-1k and IG-1 of the U.S. blast races, at the University of Arkansas at Pan Bluff and Rice Research and Extension Center from 2008 to 2009, Species Teqing and four American rice varieties Katy, Mars, LaGrue and Newbonnet complete diallel cross. The first and second generation hybrids and their parents were identified in the greenhouse by inoculation with IBA, IE-1k and IG-1 from the three major bacterial isolates of Magnaporthe grisea for complete diallel genetic analysis. The results showed that: Teqing against all races; Katy anti-IB-1 and IG-1, but sense IE-1k; Mars anti-IE-1k and IG-1, but the sense of IB-1; LaGrue flu all races; Newbonnet Anti-IG-1, but Sense IB-1 and IE-1k. Resistant varieties Teqing and susceptible varieties Newbonnet on race IB-1, resistant varieties Teqing and resistant varieties Mars against IE-1k, resistant varieties Teqing disease-resistant varieties Katy, resistant varieties Teqing and anti- The results showed that the resistant varieties Newbonnet to IB-1, IE-1k and IG-1 had the ratio of 63:1, respectively, to the IB-1, IE-1k and IG-1 3 pairs of independently inherited dominant resistance genes, overlapping genetic relationship. Resistant varieties Teqing and resistant varieties Katy, resistant varieties Teqing and susceptible varieties LaGrue, resistant varieties Katy and susceptible varieties Newbonnet IB-1, resistant varieties Teqing and susceptible varieties Mars and susceptible varieties Lagure, resistant varieties Katy and susceptible variety Mars and susceptible variety Lagure to IG-1, the segregation ratio of the two generations of resistant and susceptible plants of reciprocal hybridization with the susceptible plants accorded with a ratio of 15:1, indicating that these disease resistance There are two pairs of independently inherited dominant resistance genes in the races of the corresponding rice blast varieties, and the genetic relationship of overlapping genes appears. The resistant varieties Mars and the susceptible varieties Katy, the susceptible varieties Lagure and the susceptible varieties Newbonnet were susceptible to IE-1k. The segregation between the two generations of resistant plants and susceptible plants was in accordance with 7 resistance: The results showed that there were two pairs of recessive disease resistance genes in Mars and two offspring of Katy, Lagure and Newbonnet and Mars in the resistant cultivar showed the genetic relationship between two dominant susceptibility genes. Resistant varieties Teqing and susceptible varieties Mars, resistant varieties Katy and susceptible varieties Mars and LaGrue to IB-1, resistant varieties Teqing and susceptible varieties Katy, LaGrue and Newbonnet pairs of IE-1k, resistant varieties Katy , Mars-Newbonnet and susceptible variety LaGrue on IG-1. The ratio of resistant and susceptible plants of reciprocal crossed generation was 3︰1, which indicated that these cultivars had significant difference on IB-1, IE-1k and IG- 1, respectively, there is a resistance gene recessive genetic relationship. The susceptible plants Mars, La-Grue and Newbonnet were susceptible to IB-1 and susceptible varieties Katy, LaGrue and Newbonnet to IE-1k, 1, IE-1k susceptibility genes are allelic.