粳稻垩白性状的QTL检测

 利用大粒粳稻DL115与小粒粳稻XL005杂交获得的F2群体200个单株为作图群体，采用复合区间作图方法，利用SSR标记对稻米垩白性状进行了数量性状基因座(QTL)检测。研究结果表明，稻米垩白粒率、垩白大小和垩白度在F3株系均呈连续分布，表现为由多基因控制的数量性状。检测到与稻米垩白性状相关的QTL 8个，分别位于第3（5个）、第5（2个）和第6（1个）染色体上，包括与垩白粒率有关的QTL 3个，与垩白大小相关的QTL 2个，与垩白度有关的QTL 3个。其中位于第3染色体RM6832-RM411、RM15456-RM6832和RM6266-RM15456区间的qPGWC3、qACE3b和qDEC3b，分别解释垩白粒率、垩白大小和垩白度表型变异的43.89%、18.83%和19.57%，为主效QTL。上述3个主效QTL所在染色体上的位置与前人研究结果均不一致，认为是新的QTL。所检测到的8个QTL中，除qPGWC6的增效等位基因来自无垩白亲本XL005外，其他7个QTL的增效等位基因均来自垩白性状值较大的亲本DL115。垩白粒率和垩白大小基因作用表现为部分显性，垩白度基因作用表现为加性。

Detection of Quantitative Trait Loci for Chalky Traits in japonica Rice

Using an F2 population including 200 individuals derived from a cross between two japonica rice DL115 with large grain and XL005 with small grain, the quantitative trait loci (QTLs) for chalky traits of rice were identified by composite interval mapping using SSR markers. Three chalky traits, i.e. percentage of grains with chalkiness (PGWC), area of chalky endosperm (ACE) and degree of endosperm chalkiness (DEC), exhibited a continuous distribution in F3 lines, indicating that these chalky traits were quantitative traits controlled by multiple genes. Five, two and one QTLs conferring chalky traits were detected on chromosomes 3, 5 and 6, respectively, including three QTLs for PGWC, two QTLs controlling ACE and three QTL conferring DEC. qPGWC3, qACE3b and qDEC3b were located in RM6832-RM411, RM15456-RM6832 and RM6266-RM15456, and explained 43.89%, 18.83% and 19.57% of the observed phenotypic variance for PGWC, ACE, and DEC, respectively. They were major QTLs and new QTLs. Among the detected eight QTLs, qPGWC6 allele was derived from XL005 without chalky grain, the other seven QTL alleles were derived from DL115 with big chalky grain. The gene actions were partially dominant at PGWC and ACE, and additive at DEC.