【作者】 许凌；

【导师】 王才林；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 水稻的生育期、产量和粒型性状都是典型的数量性状,利用传统的育种方法对其进行改良,效率较低,而分子标记辅助选择（MAS）是一种较为有效的育种途径。要实现MAS在育种中的应用,首先就要获得主效QTL。目前的绝大部分研究只是在单一环境下针对少数几个性状进行相关QTL的检测,缺乏环境稳定性分析和对控制多种性状的重要染色体区间的检测,难以发掘出对环境钝感的QTL和重要染色体区间。本研究利用热研2号（粳稻）和密阳23（籼稻）为亲本构建的含111个株系的F₆和F₇重组自交系群体,在2005与2006年对生育期、株高和9个产量性状、2006年对精米的4个粒型性状进行了QTL定位及遗传参数分析。主要研究结论如下:1.对生育期、株高、穗长、一次枝梗数、二次枝梗数、单株穗数、每穗颖花数、每穗实粒数、结实率、千粒重和单株产量等11个性状进行QTL分析的结果,共检测到分布于第1、第2、第3、第4、第6、第7、第8和第10条染色体上的38个QTL,其中2005年共检测到22个QTL,2006年共检测到27个QTL,两年共同检测到的QTL共有11个。它们分布于第1、第3、第4、第6、第8和第10条染色体上,分别是qHD8、qPH8、qPH10、qPL6a、qPBN8、qSBN4、qPNP1、qSP4、qSP8a、qFGP8和qGWP8b。其中,qHD8的平均LOD值为7.83,平均贡献率为24.2%;qPH8和qPH10的平均LOD值分别为5.84和3.18,平均贡献率分别为15.92%和12.94%;qPL6a的平均LOD值为3.44,平均贡献率为9.24%;qPBN8的平均LOD值为6.90,平均贡献率为20.83%;qSBN4的平均LOD值为4.79,平均贡献率为14.16%;qPNP1的平均LOD值为5.19,平均贡献率为17.27%;qSP4和qSP8a的平均LOD值分别为3.69和6.46,平均贡献率分别为13.76%和17.91%;qFGP8的平均LOD值为4.36,平均贡献率为13.28%;qGWP8b的平均LOD值为7.17,平均贡献率为22.86%。2.2006年对粒长、粒宽、粒厚、长宽比4个性状进行了QTL分析,共检测到分布于5条染色体上的12个QTL。其中第2染色体上控制粒宽的qGW2与控制千粒重的qTGW2位于同一区域,并与控制粒厚的qGT2位于相邻区域。这与相关性分析中粒重与粒宽的相关性最大（0.631）,与粒厚的相关性其次（0.487）的结果一致。综上所述,本研究共检测到15个控制株高、穗长、产量性状和粒型性状的50个QTL。其中在2年间能够稳定表达的QTL有11个,分别是qHD8、qPH8、qPH10、qPL6a、qPBN8、qSBN4、qPNP1、qSP4、qSP8a、qFGP8和qGWP8b。同时大多数性状之间具有显著的表型相关性,相关性较强的性状之间具有较多共同或紧密连锁的QTL。如第2染色体存在一个既控制粒宽和千粒重又影响粒厚的QTL簇;第4染色体上RM303—RM280区域内检测到了同时控制二次枝梗数的qSBN4、控制每穗颖花数的qSP4、控制每穗实粒数的qFGP4和控制株高的qPH4;第8染色体上则存在一个与产量相关的QTL热点区域（RM5556—RM331）,同时存在6个控制两年产量相关性状qGWP8b、qHD8、qPH8、qPBN8、qSP8a和qFGP8)。这些研究结果为水稻的优质高产MAS育种奠定了基础。更多还原

【Abstract】 Heading date,yield component traits and grain shape related traits have been shown to be quantitatively inherited.Therefore,the use of marker-assisted selection(MAS) may provide a more efficient approach for improving these quality traits than classical breeding alone.The first step of MAS that to be carried out is mapping major loci.However,most of the studies were conducted in a single environment of only a few traits,the stability of the resultant QTL and the important chromosome regions that control different traits could not be evaluated.In this study,a set of 111 recombinant inbred lines(RIL) population derived from a rice cross between Nikken 2 and Milyang 23 through successive selfing for six and seven generations were used to investigate the QTLs of heading date,plant height,nine yield component traits in 2005 and 2006.We also investigate the QTLs of 4 grain shape traits in 2006.The main results were as follows:1.We detected eleven traits including heading date,plant height,panicle length, primary branch number,secondary branch number,spikelet numbers per panicle,number of filled grains per panicle,seed setting rate,number of panicles per plant,1000-grain weight and grain yield per plant in both two years.A total of 38 QTLs were identified on chromosome 1,2,3,4,6,7,8 and 10.We detected 22 QTLs in 2005 and 27 QTL in 2006. Of which 11 QTLs were detected in the two years.These QTL were identified on chromosome 1,3,4,6,8 and 10.The stable QTLs were qHD8,qPH8,qPH10,qPL6a, qPBN8,qSBN4,qPNP1,qSP4,qSP8a,qFGP8 and qGWP8b,whose averge PVEs were 24.2%,15.92%,12.94%,9.24%,20.83%,14.16%,17.27%,13.76%,17.91%,13.28%, 22.86%,with average LOD scores of 7.83,5.84,3.18,3.44,6.90,4.79,5.19,3.69,6.46, 4.36,7.17,respectively.2.In 2006,we analysis the QTLs of four grain shape traits including grain length,grain width,grain thickness and length/width ratio.A total of twelve QTLs distributed on five chromosomes were detected.QTL mapping showed that on chromosome 2 grain width shared the same chromosome region with 1000-grain weight,which closed to qGT2.This result was consistent with the result of correlation analysis in which grain weight was closely correlated with grain width(0.631),and then with grain thickness(0.487).In conclusion,a total of 50 QTLs for fifteen traits including heading date,plant height, yield component traits and grain shape traits.Of which qHD8,qPH8,qPH10,qPL6a, qPBN8,qSBN4,qPNP1,qSP4,qSP8a,qFGP8 and qGWP8b were detected in two years. Some QTLs controlling different traits shared the same marker interval in the chromosome with each other,which is consistent with their significant phenotypic correlations.A QTL cluster for grain width,1000-grain weight and grain thickness was located on chromosome 2.We also found a QTL cluster on chromosome 4(RM303-RM280),which including 4 QTL--qPH4,qSBN4,qFGP4 and qSP4.The most important chromosome region we found in this research is the QTL cluster on chromosome 8(RM5556-RM331) which concluding qGWP8b,qHD8,qPH8,qPBN8,qSP8a and qFGP8.These results will provide useful information for elite rice breeding by MAS.更多还原