基于粳稻F2和F2:6群体的连锁图谱及剑叶性状QTL比较分析

 以粳稻沈农265和丽江新团黑谷 (LTH) 为亲本，分别构建了F2群体和F2:6群体，分析并比较了两群体的遗传信息和控制剑叶相关性状(剑叶长、宽和比叶重)的数量性状基因座。结果表明：1)多数标记在染色体上的顺序相同，但标记间距不同。F2群体中30个标记显著偏离预期的1∶2∶1孟德尔分离比例，13个标记极显著偏离预期的1∶2∶1孟德尔分离比例，其中19个偏向沈农265，11个偏向LTH。F2:6群体中62个标记显著偏离预期的1∶1孟德尔分离比例，38个标记极显著偏离预期的1∶1孟德尔分离比例，其中43个偏向沈农265，19个偏向LTH。偏分离标记共形成10个偏分离区域，其中有6个区域同时出现在两个群体中。2) F2:6群体检测QTL的能力强于F2群体。F2群体共检测到7个控制剑叶性状的QTL (2个控制剑叶长，4个控制剑叶宽，1个控制比叶重)，而F2:6群体共检测到17个控制剑叶性状的QTL (7个控制剑叶长，5个控制剑叶宽，5个控制比叶重)，其中有4个QTL在两群体中同时检测到，分别是第9染色体上控制剑叶长的qFLL9，第4染色体上控制剑叶宽的qFLW4，第12染色体上控制剑叶宽的qFLW12.1和第6染色体上控制比叶重的qSLW6。其中，控制比叶重的qSLW6 (加性效应值为1.956 mg/cm2)，极富研究与应用价值。

Comparison of Genetic Linkage Map and QTLs Controlling Flag Leaf Traits Based on F2 and F2:6 Populations Derived from Japonica Rice

A comparative analysis was performed on genetic information and QTLs controlling flag leaf traits including length, width and specific leaf weight of flag leaf between two populations (F2 and F2:6) derived from a cross between two japonica rice cultivars, Shennong 265 and Lijiangxintuanheigu(LTH). On the two genetic linkage maps most markers had the same order along chromosomes, but the genetic distance between two markers was different. Thirty and thirteen markers showed genetic distortion significantly and extremely significantly in F2 population, separately. Nineteen and eleven markers deviated toward Shennong 265 and LTH, separately. Sixty two and thirty eight markers showed genetic distortion significantly and extremely significantly in F2:6 population, separately. Forty three and nineteen markers deviated toward Shennong 265 and LTH, separately. These distortional markers formed ten segregation distortion regions (SDRs). Six of them were detected in both F2 and F2:6 populations. F2:6 population had more powerful detective ability than F2 population in QTL dectection. Seven QTLs controlling flag leaf traits including two controlling leaf length, four controlling leaf width and one controlling specific weight were detected in F2 population. Whereas seventeen QTLs for these traits (seven for leaf length, five for leaf width and five for specific leaf weight) were detected in F2:6 population. Four QTLs were detected in both populations including qFLL9 controlling flag leaf length on chromosome 9, qFLW4 controlling flag leaf width on chromosome 4, qFLW12.1 controlling flag leaf width on chromosome 12 and qSLW6 controlling specific leaf weight on chromosome 6. Among them, qSLW6 (Additive effect was 1.956 mg/cm2) for specific leaf weight has a high research and application value.