Abstract: To dissect the genetic basis of yield and its related traits, the QTLs controlling whole growth period (WGP), plant height (PH), number of panicles per plant (PN), number of grains per panicle (GN), hundredkernel  weight (HKW), grain yield (GY) and biomass yield (BY)  were detected by unconditional and conditional approaches  with the recombinant inbred lines derived from a cross between two  japonica varieties, Xiushui 79 and C Bao in three environments. Fourtythree  maineffect QTLs and 29 pairs of epistatic QTLs were detected.  By the unconditional method, 37 maineffect QTLs and 26 pairs of epistatic QTLs were detected. Three  maineffect QTLs, qGY1.2, qGY7.1 and  qGY9, were found for GY while no epistatic QTL was found for GY.  By the conditional method,  9 maineffect QTLs and 3 pairs of epistatic QTLs for GY including the three maineffect QTLs detected by unconditional methods were detected.  qGY9, in the interval RM6570-RM5652   on the long arm of chromosome 9, could be detected by unconditional method and conditional method when  WGP, PH, PN, GN and HKW were at the same levels, but the additive effect and the variance explained were different. The allele  of qGY9 contributed by  C Bao could increase GY through increasing PH, HKW and PN. The alleles at  the interval RM7097-RM448  on the long arm of chromosome 3 and the interval RM162-RM5753  on the long arm of chromosome 6 detected by the conditional method  which could increase GY had negative effects on PH and WGP.

Key words: japonica rice, yield, quantitative trait locus

摘要： 为了剖析粳稻产量及其相关性状的遗传基础，利用粳稻品种秀水79×Ｃ堡衍生的重组自交系群体，在3个环境下对全生育期、株高、单株穗数、每穗粒数、百粒重、籽粒产量和生物产量进行了非条件和条件QTL定位。共检测到43个主效QTL和29对上位性QTL。利用非条件QTL定位方法检测到37个主效QTL和26对上位性QTL。其中，籽粒产量定位到3个主效QTL qGY1.2、qGY7.1和qGY9，未检测到上位性QTL。利用条件QTL方法分别将全生育期、株高、穗数、每穗粒数、百粒重和生物产量各自调整到同一水平后，籽粒产量共检测到9个主效条件QTL和3对上位性QTL，其中3个主效QTL与非条件下定位到的相同。位于第9染色体长臂区间RM6570-RM5652的qGY9在非条件及全生育期、株高、穗数、粒数和百粒重调整到同一水平后均可检测到，但加性效应、贡献率并不相同，显示该区间来自C堡的片段能够增加株高、穗数和百粒重从而增加产量。通过条件方法在第3染色体长臂区间RM7097-RM448及第6染色体长臂区间RM162-RM5753上定位到的产量QTL增加籽粒产量的等位基因可以降低株高，缩短生育期。

关键词: 粳稻, 产量, 数量性状基因座