控制水稻穗形相关性状的QTL定位

Detection of QTLs for related traits of panicle in rice(Oryza sativa L.)

穗是水稻产量的最终表达部位,穗部性状在产量构成因素中占有很重要的地位。该研究采用以粳稻Asominori为遗传背景、籼稻IR24为染色体片段供体的染色体片段置换系(Chromosome segment substitution lines,CSSLs)群体,于2007年和2008年对水稻穗部性状进行了相关分析及其数量性状位点(Quantitative trait loci,QTL)的定位。结果表明:穗部性状与单株产量存在极显著的正相关,并检测到影响5个相关性状的33个QTL,分布在第1、第3、第4、第6和第8条等染色体上,贡献率介于5.35%与37.59%之间,其中两年同时检测到的稳定表达QTL10个,约占30.3%;在第1染色体RM493和RM5496标记附近、第4染色体RM317标记附近、第6染色体RM217标记附近和第8染色体RM331及RM502标记位置均检测到能同时控制穗部多个性状的QTL,可能是因为基因的多效性或基因的紧密连锁所致。在育种中利用与这些QTL连锁的分子标记进行辅助选择,将有助于多个性状的协同改良。

Panicle is one of the most important sink organs,and traits of which have significant influence on the components of yield in rice（Oryza sativa L.）.Correlations and QTL analyses of five main traits affecting panicle traits in rice were conducted in years 2007 and 2008 in Nanjing using chromosome segment substitution line（CSSL） population consisting of 66 lines,derived from a cross between a japonica cv.Asominori（as a recipient parent） and an indica cv.IR24（as a donor parent）.The results revealed that there existed significantly positive correlations between the five traits studied and yield per plant.A total of 33 QTLs controlling above five panicle traits were detected and located on chromosomes 1,3,4,6 and 8,respectively,which could explain 5.35%-37.59% of total phenotypic variance.Several QTLs on chromosomes 1,4,6 and 8 affecting related traits of panicle at the same time were detected for the reason of pleiotropic effects or the tight linkage of QTLs.Using these QTL clusters for marker-assisted selection（MAS） would contribute to the improvement of multiple traits simultaneously in breeding.