水稻千粒重和垩白粒率的QTL及其互作分析

QTL Mapping and Interaction Analysis for 1000-Grain Weight and Percentage of Grains with Chalkiness in Rice

产量因子千粒重和稻米品质指标垩白粒率密切相关。本研究以越光/Kasalath//越光BIL群体为材料,分析千粒重和垩白粒率的相关性、QTL、上位性互作及其与环境的互作效应。相关分析表明,群体千粒重和垩白粒率在2005年和2006年均呈极显著正相关,相关系数分别为0.42和0.35(P<0.001)。2年共检测到千粒重QTL11个,其中5个在2年重复检测到,5个具有环境互作效应;千粒重上位性互作8对,7对与环境存在互作。垩白粒率QTL6个,3个具有环境互作效应;上位性互作9对,其中4对具有上位性环境互作效应。比较分析发现3个主效QTL同时控制千粒重和垩白粒率的表现,千粒重和垩白粒率的增效等位基因来自同一亲本;1对上位性互作同时对千粒重和垩白粒率有相同的影响。一些与垩白粒率不相关的千粒重主效QTL,如qTGW-3c、qTGW-4a和qTGW-6b,可为育种所利用。对利用QTL定位结果进行千粒重和垩白粒率分子辅助选择育种进行了探讨。

There is a close correlation between 1000-grian weight （TGW, an important yield factor） and percentage of grains with chalkiness （PGWC, an important rice quality index）. In this study, a backcross inbred lines （BIL） population derived from a cross between Koshihikari （japonica） and Kasalath （indica） was used to detect correlations and among interactions QTL, epistatic and environment on TGW and PGWC. Correlation analysis showed that there was a significantly positive correlation between TGW and PGWC in the BIL population and the correlation coefficients were 0.42 and 0.35 （P〈0.001） in 2005 and 2006, respectively. A total of eleven QTLs and eight epistatic interactions for TGW were detected in 2005 and 2006; of them, five QTLs were repeatedly detected in the two years, and five QTLs and seven epistatic interactions had significantly QE interaction. A total of six QTLs and nine epistatic interactions for PGWC were detected in 2005 and 2006; of them, three QTLs and four epistatic interactions had markedly QE interaction. Three main-effect QTLs simultaneously controlling TGW and PGWC were detected, and their alleles increasing TGW and PGWC were from the same parent; one epistatic interaction had similar effects on TGW and PGWC. Some main-effect QTLs, controlling TGW but not PGWC, such as qTGW-3c, qTGW-4a, and qTGW-6b, could be used for breeding. The strategy was discussed in using QTL mapping results for the marker-assisted selection breeding of TGW and PGWC.