高粱bmr和光周期敏感基因遗传分析及初步定位

Study on inheritance and mapping of sorghum brown midrib bmr and photoperiod-sensitive genes

通过田间和实验室相结合把低木质素、高消化率基因bmr和光周期敏感基因PS聚合到饲草高粱中,以提高饲草高粱的产量和品质。以含PS基因的EBA-3和含bmr基因的Tx623B配制杂交组合,构建了F2代分离群体。根据表型分离比例分析,光敏和褐色中脉可能分别受两对彼此独立的非等位基因控制,并且基因之间存在着互作。光敏基因之间存在互补作用,褐色中脉基因之间存在抑制作用。根据高粱的遗传连锁图谱,选取相应的SSR标记。经连锁遗传分析,找到了2个SSR标记,Xtxp7与bmr基因连锁,Xtxp20与PS基因连锁。由于Xtxp7位于连锁群B,Xtxp20位于连锁群G,据此认为高粱有一个bmr基因位于B染色体上和有一个PS基因位于G染色体上。这两个标记的获得可用于标记辅助育种,加速杂交种的转育与利用。此外,对影响开花时间的QTLs和主效基因在高粱和水稻上可能一致进行了讨论。

The bmr（brown midrib） gene of low lignin and high digestibility and PS（photoperiod-sensitive） gene were pyramided into a forage sorghum line through a combinaed field and laboratory study to improve the yield and quality.EBA-3 with PS gene and Tx623B with bmr gene were employed to construct a F2 segregation population.Phenotype segregation ratio showed the two traits PS（photoperiod-sensitive） and bmr（brown midrib） might be controlled by two independent genetic loci,respectively.The two PS loci showing complementary effects,while the two bmr loci were inhibitory.SSR marker Xtxp7 in linkage group B,was linked with bmr gene,while Xtxp20 in linkage group G was linked with PS gene.These markers were used for marker assisted selection for the introgression breeding.Evidence for possible orthologies of the genes detected here with other QTLs and major genes involved in flowering time of sorghum and rice is discussed.