利用籼粳交BIL群体定位水稻谷粒长宽比QTL

Quantitative trait locus( QTL ) mapping of grain length-width ratio by using indica-japonica backcross inbred line( BIL) population in rice

本研究以122个南粳35/N22//南粳35构建的回交重组自交系（BIL）群体为材料,通过两年重复试验,利用Win QTLcart2.5和QTLNetwork2.0软件对控制水稻谷粒长宽比的数量性状基因位点（QTL）进行定位分析。利用Win QTLcart2.5共检测到5个控制谷粒长宽比的QTLs,分别位于第1、4、5、7和12染色体上,单个QTL对表型的贡献率为8.80%～18.83%。利用QTLNetwork2.0共检测到4个QTLs,贡献率为7.36%～16.05%,除q LWR-1未被检测到外,其余QTLs与Win QTLcart2.5检测结果吻合,除q LWR-4外,谷粒长宽比增效基因均来自长粒型水稻品种N22;此外还检测到3对上位性QTLs,贡献率为1.12%～4.97%。

The quantitative trait locus （QTL） controlling grain length-width ratio were mapped by using a backcross inbred lines （BIL） population derived from a cross between a japonica parent Nanjing35 and an indica parent N22. Five putative QTLs were identified on chromosomes 1, 4, 5, 7, 12 using WinQTLcart2.5 software in two years, and the percentage of phenotypic variance explained ranged from 8.80% to 18.83%. Four putative QTLs were mapped on chromosomes 4, 5, 7, 12 using QTLNetwork2.0 software, explaining 7. 36% to 16. 05% phenotypic variation. Except for qLWR- 1, the location and effect were the same to those using WinQTLcart2. 5. Alleles of these QTLs were from long-grained variety N22 except for qLWR-4. Three pairs of epistatic QTLs were also detected, explaining 1.12% to 4. 97% phenotypic variation. No significant interaction was detected between QTLs and environments.