Abstract: Panicle angle of the RIL population derived from a cross between two japonica varieties Xiushui 79 and C Bao was investigated in four growing environments. Genetic analysis was conducted by mixed major gene plus polygene inheritance models, and QTL identification was performed by QTLNetwork 2.0 and composite interval mapping approach of WinQTLcart 2.5 software in the RIL population. Results were as follow: 1) panicle angle was controlled by two major genes plus polygenes, mainly by major genes; 2) eight QTLs were detected by QTLNetwork 2.0 software, explaining 0.01%-39.89% phenotypic variation. 12 QTLs were detected by WinQTLcart 2.5 software, explaining 2.83%-30.60% phenotypic variation. All the QTLs detected above were located on chromosomes 4, 5, 6, 7, 9 and 11. Of which, two major QTLs (qPA9.2 and qPA9.5) at RM3700-RM3600 and RM5652-RM410 and qPA9.7 at RM257-OSR28 were all detected by the two methods in the four environments. The negative effect alleles of the three QTLs were contributed by Xiushui 79; 3) eight pairs of epistatic QTLs with few effects were also detected. QTL × environment interactions were not significant for additive QTLs and epistatic QTL pairs.

Key words: japonica rice, panicle angle, growing environment, mixed inheritance models, QTL

摘要： 在4个环境下种植直立穗粳稻品种秀水79与弯曲穗品种C堡及两者杂交后衍生得到的RIL群体254个株系并调查其穗角，运用主基因+多基因混合遗传模型对穗角性状进行遗传分离分析；运用基于混合线性模型的QTLNetwork 2.0软件和基于多元回归模型的WinQTLcart 2.5软件的复合区间作图法，对穗角性状进行QTL定位。结果发现，1）穗角性状受两对主基因+多基因共同控制，以主基因遗传为主；2）QTLNetwork 2.0检测到8个控制穗角性状的加性QTL，解释表型变异的0.01%~39.89%；WinQTLcart 2.5检测到12个控制穗角性状的加性QTL，可解释表型变异的2.83%~30.60%。检测到的所有QTL分布于第4、5、6、7、9、11染色体上，其中分布于RM3700-RM3600和RM5652-RM410区间的两个主效位点qPA9.2和qPA9.5，以及分布于RM257-OSR28区间的qPA9.7 在两种方法和4个环境下均检测到，减效等位基因来自秀水79；3）检测到8对加性×加性上位性互作位点,解释表型变异的0.36%~1.71%。检测到的各个加性和上位性位点均不存在显著的基因型与环境的互作。 

关键词: 粳稻, 穗角, 生长环境, 混合遗传模型, QTL