粳稻柱头外露率QTL定位

【目的】柱头外露是影响杂交水稻制种的一个重要性状。本研究旨在初步鉴定控制柱头外露率的QTL。【方法】以高柱头外露率粳稻两系不育系大S×低柱头外露率热带粳稻品系D50的F_2群体及海南陵水、浙江杭州两地重复种植的F_(2:3)群体为材料,考查F_2群体及陵水、杭州两地两次重复F_(2:3)群体单边柱头外露率(PSES)、双边柱头外露率(PDES)和柱头总外露率(PES)。【结果】相关分析表明,单边柱头外露率、双边柱头外露率和柱头总外露率之间存在极显著的正相关。根据构建的大S×D50 F_2群体遗传连锁图谱,QTL分析检测到水稻柱头外露率QTL 21个,分布于第1、2、3、4、6、7和12染色体上,贡献率变幅为0.1%~57.6%,除个别贡献率极低的位点外,绝大部分QTL加性效应来自于高值亲本大S。其中位于第4染色体和第12染色体的两个位点q PDES4,q PES12在F_2和两次重复F_(2:3)群体中均检测到,贡献率分别达17.86%和16.98%。位于第3染色体的q PES3位点在陵水、杭州两次F_(2:3)群体中重复检测到,贡献率高达25.6%。【结论】检测到的QTL,有些与其他学者报道的处于同一位置,有些则是新的柱头外露率QTL。这些水稻柱头外露率QTL为今后柱头外露率基因精细定位、克隆、以及利用分子标记辅助选择(MAS)选育高柱头外露率粳型不育系提供理论依据。

QTL Mapping of japonica Rice Stigma Exsertion Rate

【Objective】Stigma exsertion is one of the important traits which contribute to the efficient improrement of commercial seed production in hybrid rice. The objective of the study was to understand the genetic factors involved in the sigma exsertion.【Method】 The F2 and F2:3 populations of Da S×D50 planted in Lingshui, Hainan Province and Hangzhou, Zhejiang Province, respectively were used and the single stigma exsertion rate (PSES), double stigma exsertion rate (PDES) and total stigma exsertion rate (PES) were measured. 【Result】Correlation analysis indicated that there were significant relationships among the PSES, PDES and PES. Further, the genetic linkage map of Da S×D50 F2 population was constructed, then, 21 stigma exsertion rate QTL were located on chromosome 1,2,3,4,6,7 and 12, respectively, with the contribution rate ranging from 0.1% to 57.6%. The additive effect of most QTLs were contributed by high value parent Da S except for some QTL that with extremely low contribution rate. There were two QTLs on Chromosome 4 and Chromosome 12, qPDES4 and qPES12, both detected in F2 and F2:3 populations with contribution rate as high as 17.86% and 16.98%, respectively. The qPES3 located on Chromosome 3 with high contribution rate were detected in F2:3 population for two times. 【Conclusion】Some stigma exsertion rate QTL shared the same location with those reported by other researchers, but there were also some new QTLs which provide theoretical support for further fine mapping, gene cloning, and breeding new japonica male sterile lines with high stigma exsertion rate by using molecular marker assistant selection.