江淮稻区杂交粳稻骨干亲本产量性状配合力的SSR标记位点鉴定

Identifying SSR Marker Locus Genotypes with Elite Combining Ability for Yield Traits in Backbone Parents of Japonica Hybrid Rice(Oryza sativa L.) in Jianghuai Area

鉴定杂交粳稻亲本产量性状配合力的标记位点有助于利用分子标记辅助选择技术改良亲本配合力、提高杂交粳稻竞争优势水平。利用9个粳稻BT型不育系和10个恢复系,按照北卡罗林那设计Ⅱ(North Carolina DesignⅡ)配制90个F_1组合,在南京和盱眙两个环境下种植,测定了各亲本产量性状的配合力和SSR分子标记基因型;结合二者数据鉴定了6个产量性状配合力的标记位点。结果表明,在2个环境下综合评价配合力较优的不育系是BT-18A和武羌A,恢复系是C418。与亲本单株有效穗数、每穗总粒数、每穗实粒数、结实率、千粒重和单株日产量性状配合力显著相关的SSR标记位点,南京环境下分别检测到8、13、11、6、6和2个;盱眙环境下分别检测到12、21、8、15、10和7个;2个环境下都检测到的分别有4、11、5、3、5和1个。标记位点杂合基因型显示正向优势的,南京环境下占74%(34/46);盱眙环境下占53%(39/73)。2个环境下都检测到的标记位点中,有3个各自与3个产量性状配合力共相关;另有3个各自与2个产量性状配合力共相关;其余的只与单个产量性状配合力显著相关。数据库检索发现两环境下都检测到的标记位点中,有10个其附近存在控制相应性状的基因/QTL。讨论了利用鉴定出的标记位点改良粳稻恢复系产量性状配合力的策略。

Identifying marker loci related to combining ability （CA） for yield trait in parents of japonica hybrid rice facilitates improving CA of parents and enhancing standard heterosis degree of japonica rice by using molecular marker-assisted selection techniques. F1 seeds of 90 combinations were made by hand-crossed nine CMS lines with ten restorer lines using North Carolina Design II. The F1 populations were planted in Nanjing and Xuyi environments, and six yield traits were investigated. CA of the 19 parental lines was analyzed for six yield traits respectively using the data of 90 F1＇s. Combining the data of CA and SSR marker genotypes of the 19 parental lines, SSR marker loci related to CA for six yield traits were detected. Results showed that BT-18A and Wuqiang A were elite CMS lines, and C418 was elite restorer lines in both environments. Number of detected SSR marker loci related to CA for effective panicles per plant, spikelets per panicle, filled grains per panicle, seed setting rate, 1000-grain weight and daily yield per plant were 8, 13, 11, 6, 6, and 2, respectively in Nanjing, 12, 21, 8, 15, 10, and 7, respectively in Xuyi, and 4, 11, 5, 3, 5, and 1, respectively in both environments. Heterozygous genotype marker loci showing positive heterosis accounted for 74% （34/46） in Nanjing, and 53% （39/73） in Xuyi. Among the SSR marker loci detected in both environments, three were each co-associated with CA for three yield traits, and another three for two yield traits. The remaining 14 marker loci were each associated with CA for one yield trait. Through data-base searching, genes/QTLs for the corresponding traits were found nearly ten of the marker loci detected in both environments. Strategies of enhancing CA for yield traits of restorer lines in japonica rice using the marker loci identified in this study were discussed.