控制水稻抽穗期和株高的QTL的定位及遗传分析

Mapping and Genetic Analysis of QTL for Heading Date and Plant Height in Rice

抽穗期(headingdata,HD)和株高(plantheight,PH)是水稻(Oryza sativaL.)非常重要的农艺性状。本研究利用金23B(Jin23B)和青谷矮1号(QGA-1)构建的BC3F1群体及其衍生的BC3F2群体通过分子标记定位水稻抽穗期和株高的QTL(quantitativetraitlocus)。构建的遗传连锁图包含105对SSR标记和8对InDel标记,图谱较好地覆盖了水稻12条染色体。两年来共定位到了9个抽穗期相关QTLs,6个株高相关的QTLs,其中抽穗期和株高最大效应都来源于第7染色体。抽穗期QTLqHD7-3在2011年LOD为37.07,可以解释的表型贡献率为41.05%,加性效应为11.68;株高QTLqPH7-2在2011年LOD为43.73,可以解释的表型贡献率为54.17%,加性效应为21.60;2012年LOD为42.66,可以解释的表型贡献率为54.39%,加性效应为19.95。qHD7-3和qPH7-2位于同一区域RM214-RM5543之间,Ghd7也位于这一区间,该QTL可能是Ghd7的等位基因。抽穗期QTLqHD2定位于第2染色体上标记ZH282和RM71之间,在两年内都能检测到,其LOD值分别为4.56和4.99,可解释的表型贡献率分别为4.31%和7.99%。株高QTLqPH4定位于第4染色体上标记RM241和RM317之间,其两年内的LOD分别为2.89和2.67,解释的表型贡献率为9.42%和8.78%。抽穗期QTL qHD2和株高QTL qPH4所定位的区间没有相关的基因或QTL报道,这两个QTL可能含有控制抽穗期和株高的新基因。本研究通过遗传定位证明了株高和抽穗期是由主效QTL和微效QTL共同控制的,并发掘了新的抽穗期和株高的QTL,为育种家利用分子标记辅助选择培育新品种提供更多的选择。

Heading date（HD） and plant height（PH） are significant agronomic traits in rice（Oryza sativa L.）. In order to analyze the HD and PH, we established BC3F1 and the derived BC3F2 backcross population of Jin23B/Qingguai-1. The genetic linkage map contains 105 pairs of SSRs and 8 InDel-markers, mainly covering 12 rice chromosomes. In two years, 9 HD QTLs（quantitative trait loci） and 6 PH QTLs were identified in these populations. The maximum effect QTLs of HD and PH are in the same location on chromosome 7. Heading date QTL,qHD7-3, with a LOD score of 37.07 in 2011, could explain 41.05% of the phenotypic variation, and the additive effect was 11.68. The plant height QTL, qPH7-2 has a LOD score of 43.73 and 42.66 in 2011 and 2012, accounting for 54.17% and 54.39% of the phenotypic variation, and the additive effect was 21.60 and 19.95 respectively.qHD7-3 and qPH7-2 were both located between marker RM214-RM5543, where Ghd7 is located, suggesting that it may be the allele of Ghd7. Heading date QTL qHD2 was mapped between marker ZH282 and RM71 on chromosome 2, with a LOD score of 4.56 and 4.99 in 2011 and 2012, which could explain 4.31% and 7.99% of the phenotypic variation respectively. Heading date QTL qHD4 was mapped between marker RM241 and RM317 on chromosome 4, with a LOD score of 2.89 and 2.67 in 2011 and 2012, interpreting 9.42% and 8.78% of the phenotypic variation respectively. The regions of qHD2 and qPH4 have no genes reported about HD and PH previously, thus the region might be a new gene. Our work proved that HD and PH were controlled by major and minor QTL. The exploration of new HD and PH QTL provided more choices in breeding new varieties.