稻米粒形和垩白度的QTL定位和上位性分析

 利用由181个家系组成的Lemont/特青籼粳交重组自交系群体，以及由161个RFLP、SSR标记和3个形态标记构建的全长为1916.5 cM、覆盖水稻基因组12 条染色体的连锁图，采用线性模型的复合区间作图方法（QTLMapper V10），对粒长、粒宽、长宽比和垩白度等4个稻米品质性状的数量性状座位（QTL）进行了分析。在水稻的所有12 条染色体上共定位到7个加性主效QTL和19对上位性QTL，其中控制粒长、粒宽、长宽比的主效QTL各2个，控制垩白度的QTL 1个，分别解释12.8%、40.0%、26.0%和42.1%的表型变异；共检测到6对影响垩白度、6对影响粒长、7对影响长宽比的上位性QTL，分别解释52.2%、31.3%和38.2% 的表型变异。结果表明，上位性QTL和主效QTL一样在稻米粒形和垩白度的遗传中起着重要的作用。

QTLs Mapping and Epistasis Analysis for Grain Shape and Chalkiness Degree of Rice

A total of 181 recombinant inbred lines derived from an inter-subspecific cross of Lemont (japonica)/Teqing (indica) and its genetic map were used to identify quantitative trait locus (QTL) controlling rice quality traits such as grain length (GL),grain width (GW), grain length to width ratio (LWR) and chalkiness degree (CD) by a mixed model approach (QTLMapper V1.0). A total of seven QTLs with significant additive effects and 19 pairs of QTLs showing significant additive × additive epistatic effects covering all twelve rice chromosomes were identified, Seven main effect QTLs were detected for GL, GW, LWR and CD, and the percentages of phenotypic variance explained were 12.8%, 40.0%, 26.0% and 42. 1%, respectively. Six, six and seven pairs of epistatic loci were associated with GL, LWR and CD, and the percentages of phenotypic variance explained were 52.2%, 31.1% and 38.2%, respectively. The results indicated that the epistatic effects played an important role on the inheritance about grain shape and chalkiness degree in rice.