芝麻隐性核不育保持系选育与基因型分析

Breeding and genotype analysis of recessive genic male sterile maintainer line in sesame

芝麻隐性核不育两用系杂交制种时,母本行需人工拔除分离出的50%可育株,为解决这一难题,为芝麻杂种优势利用提供新途径,采用不同遗传背景的种质与芝麻隐性核不育两用系0176AB中的不育株0176A广泛测交,在不育株率超过60%的分离世代中选取大量可育株与不育株0176A成对杂交,同时将可育株父本自交,筛选F1不育株率逐步提高的组合和父本,经过多代测交、自交、系选、异地鉴定和基因聚合,历时13年基本育成对0176A雄性不育性状具有完全(高度)保持效果的新材料WB51220、WB7-1D及高不育系W0176A和全不育系W71A。遗传测验表明,保持系WB7-1D的基因型为msms+rf_1rf_1rf_2rf_2…rf_ir_fi。两用系、保持系和恢复系可以实现芝麻隐性核不育三系配套,利用这种方法首次选育出芝麻核雄性不育三系杂交种皖芝6号(W0176A×皖芝1号F_1)和皖芝11号(W71A×皖芝2181F_1),产量分别比全国对照品种豫芝4号增产8.27%和23.0%。

Hybrid seed production requires the removal of 50% fertile plants by using recessive genic male sterile（ RGMS） two- line system（ dual purpose line,AB line）,which limited its utilization for sesame hybrid production. To simplify the seed production,different sesame germplasms were used as pollen donors to testcross with sterile plants（ 0176A） from RGMS 0176 AB line. A large number of fertile plants were then selected from testcrossing separation generation with more than 60% sterile plant. Those fertile plants were paired crossed with 0176 A again. Meanwhile,the male parents of fertile plants were self- fertilized for increased percentage of male sterile plants. After 13 years of testcross,self- cross,multiple generation systemic selection,relocation propagation,identification and gene polymerization,new bred lines WB51220（ maintainer）,WB7- 1D（ maintainer）,W0176A（ highly sterile） and W71A（ complete sterile） were obtained. Genetic tests showed that genotype of maintainer WB7- 1D was msms ＋ rf1rf1rf2rf2…rfirfi. By using the new bred sterile and maintainer lines,new cultivars Wanzhi6（ W0176 A × Wanzhi 1 F1） and Wanzhi 11（ W71 A × Wanzhi 2181 F1） were bred. The 2 cultivars had 8. 27%and 23. 0% higher yield than Yuzhi 4（ CK） respectively.