谷物胚乳性状数量基因图的构建方法及其应用

Based on the genetic models for triploid endosperm traits and methods for mapping diploid quantitative traits loci (QTL), the genetic constitutions and components of means and genetic variances under flanking marker genotypes in different endosperm generations were presented. From these results, we proposed three statistical methods for mapping QTL underlying endosperm traits that include regression with mean of flanking marker genotypes, iteratively reweighted least squares and maximum likelihood estimation implemented by expectation-maximization algorithm. The statistical power of QTL detection, accuracy and precision of QTL location and genetic effects were studied by the simulated data in different marker densities, heritabilities and sampling strategies. Efficiency of the methods is verified through extensive Monte Carlo simulation studies. Appling these methods, QTLs underlying amylose content (AC), gelatinization temperature (GT) and gel consistency (GC) in rice were analysed. The results indicate that AC, GT and GC are mainly controlled by two major QTLs, one major QTL and two linked QTLs, respectively. This study further developed molecular quantitative genetics for endosperm traits.

将三倍体胚乳性状的数量遗传模型和二倍体数量性状QTL图构建方法相结合，导出单标记和双侧标记基因型下胚乳性状QTL的遗传组成、平均数和遗传方差分量，比较其与二倍体性状雇挤椒ǖ牟钜欤岢龉任锱呷樾宰碤TL图构建的方法和计算程序。应用此方法构建米糊化温度、直链淀粉含量和胶稠度三性状的QTL图以及分子标记辅助选择指数。