影响水稻穗部性状及籽粒碾磨品质的QTL及其环境互作分析

Analyses of QTLs for Rice Panicle and Milling Quality Traits and Their Interaction with Environment

利用优质恢复系测258为轮回亲本与粳型糯稻新品系IR75862杂交创制的BC1F7回交导入系群体,在广西南宁和海南三亚定位了产量相关性状(二次枝梗数、穗总粒数、穗实粒数、粒重和穗重)、粒型(粒长、宽、厚)和碾磨品质(糙米率、精米率和整精米率)的主效QTL并剖析其环境互作效应。双亲在穗实粒数、千粒重、粒长和粒宽及整精米率等性状上存在显著差异。各产量相关性状间呈极显著正相关,而与千粒重和粒长呈极显著负相关。多数产量及粒型相关性状与3种碾磨品质相关不显著。在南宁和三亚环境下检测到影响产量相关性状、粒型及碾磨品质的主效QTL共计57个,包括二次枝梗数6个,穗实粒数4个,穗总粒数、粒重和穗重各5个,粒长9个,粒宽7个,粒厚1个,糙米率4个,精米率5个和整精米率6个,分布在除第11染色体外的所有染色体上。多数影响枝梗数、穗粒数和粒重的QTL成簇分布,而且与影响糙米率、精米率和整精米率的QTL分布在不同染色体区域。在第2、第3、第4、第5和第6染色体上鉴定出影响穗粒数、粒重、粒型及碾磨品质的重要QTL,这些QTL在以往不同遗传背景和环境下被多次检测到。在第8染色体RM152～RM310区间鉴定到1个影响粒长和粒宽的新的QTL,能同步增加粒宽和粒长。鉴定出的这些稳定表达的QTL具有标记辅助选择育种的应用价值。整精米率是受环境影响最大的性状,其QTL的环境互作效应明显。对QTL的环境互作效应特点及其在品种标记辅助改良中的作用进行了深入探讨。

QTLs and their interactions with environments for yield-related traits—second branch number（SBN）,spikelet number per panicle（SNP）,filled grains number per panicle（FGN）,1000-grain weight（TGW）,and panicle weight（PW）;grain type traits —grain length（GL）,width（GW）,and thinkness（GT）;and milling quality traits—brown rice percentage（BR）,milled rice percentage（MR）,and head rice percentage（HR） were identified and analyzed in the two environments,Nanning of Guangxi and Sanya of Hainan,using an introgression line population derived from the cross of recurrent parent Ce258 and a donor IR75862.There were significant differences in FGN,TGW,GL,GW,and HR between the two parents.Significant correlations were found among the yield-related traits,and they were strikingly negatively correlated with TGW and GL.Most yield-related traits and grain type had no significant correlations with the three milling quality traits.A total of 57 QTLs were identified for yield-related traits,grain type and milling quality,including six for SBN,four for FGN,five for each of SNP,PW,and TGW,nine for GL,seven for GW,one for GT,four for BR,five for MR,and six for HR,which distributed on all chromosomes except chromosome 11.Most QTLs affecting SBN,SNP and TGW clustered and distributed in the chromosomes independent of the QTLs for BR,MR and HR.Some important QTLs for the above traits were identified on chromosomes 2,3,4,5,and 6 which had been previously detected many times in various genetic backgrounds and environments.One QTL affecting GL and GW in the region of RM152-RM310 on chromosome 8 was newly identified,which simultaneously increased GL and GW.The stable QTLs identified in this study are of importance for marker-assisted selection（MAS） in rice breeding programs.In addition,HR was largely affected by environment and the QTLs for HR had a significant interaction with environment.The interaction characteristics of QTL with environment and its application in MAS were deeply discussed in the paper.