烟草青枯病抗性基因的遗传分析及RAPD标记

选用高感青枯病品种"红花大金元"与高抗青枯病品种"Ti448A"配制杂交组合,采用温室苗期叶片人工注射法接种鉴定两亲本及其杂交后代F₁、F₂、BC₁P₁代的青枯病抗性表现,结果表明抗病亲本材料Ti448A的抗病性由一对显性基因控制。依据混合群体分组分析法(BSA)建立抗青枯病基因池和感青枯病基因池,通过RAPD试验,从近200个随机引物中筛选出一个在两池间具有多态性的引物S503,用双亲、F₁、F₂单株DNA进行RAPD试验证明了该引物扩增出的特异性片段S503-750是一个与抗青枯病基因连锁的RAPD标记,利用JOINMAP (version 1.4)软件计算得此标记与抗青枯病基因间的重组率为5.984%,连锁距离为6.261 cM。 

Heredity and RAPD markers analysis of resistance gene to tobacco bacterial wilt

A cross between bacterial wilt resistant variety "Ti448A" and susceptible variety "Honghua Dajinyuan" was made to map bacterial wilt resistance gene (s). Resistance of the parents and the populations F₁, F₂, and BC₁P₁ were identified by artificial inoculation on seedlings in greenhouse. Results showed that resistance of "Ti448A" was controlled by twin dominant genes. DNAs of F₂ population were extracted to develop into a resistant pool and a sensitive pool based on the BSA. By RAPD, about 200 random primers were used to amplify the two gene pools. Only primer S503 was found to be polymorphic with a fragment of 750bp in parents, F₁, and F₂ populations. Therefore, the specific fragment S503-750 was a RAPD marker linked to resistance gene. Analysis using software JOINMAP (version 1.4) gave the results that the recombination ratio was 5.984% and the linking distance was 6.261 cm.