大白菜细胞核隐性雄性不育系恢复基因BrMf2的标记及定位

Mapping of Recessive Genic Male Sterile Restoring Gene (BrMf2) in Brassica rapa L.ssp.pekinensis

【目的】筛选大白菜细胞核隐性雄性不育(RGMS)育性基因(Mf)的连锁标记,通过定位该基因,为克隆雄性不育基因打下基础。【方法】939A不育系与YQD56A杂交F1S4后代为试材,利用混合分组分析法(BSA),应用SRAP和SRAP-AFLP标记技术筛选引物1256对。【结果】获得与大白菜细胞核隐性雄性不育恢复基因连锁的标记2个,PM8K4和Me2M49,与恢复基因的遗传距离分别为2.98cM和10.92cM。通过调查PM8K4标记在大白菜DH作图群体中的多态性,将该基因定位在A8连锁群,即大白菜第9染色体。【结论】标记PM8K4可以在苗期对大白菜细胞核雄性不育性状进行标记辅助选择。

[ Objective] Recessive genic male sterility （RGMS） is one of the important methods for F1 seeds production in Chinese cabbage （Brassica rapa L. ssp. pekinensis）. Identification of molecular markers linked to RGMS restoring gene not only can accelerate breeding programs, but also can provide information for cloning of RGMS gene by mapping this gene on the corresponding chromosome. [ Methods ] A segregating population was developed from a cross between a male sterile line 939A and a fertile line YQD56A. SRAP and SRAP-AFLP techniques and bulked segregant analysis （BSA） were used to screen markers linked to the RGMS restoring gene. [Result] Among the 1 256 primer combinations, only PM8/K4 and Me2/M49 showed polymorphism between bulks of male sterile and fertile. The polymorphic bands were named as PM8K4 and Me2M49. The distance of PM8K4 and Me2M49 was 2.98 cM and 10.92 cM, respectively. PM8K4 was subsequently mapped on linkage group A8 （Chr9） using a doubled-haploid mapping population. [ Conclusion ] The SRAP and SRAP-AFLP markers developed here can be used in breeding programs for Chinese cabbage.