关键词: 相关群体, 数量性状座位, 基因定位, 极大似然估计方法

Abstract: It’s well-known that incorporating some existing populations derived from multiple parents may improve QTL mapping and QTL-based breeding programs. However, no general maximum likelihood method has been available for this strategy. Based on the QTL mapping in multiple related populations derived from two parents, an maximum likelihood estimation method that can incorporate several populations derived from three or more parents and can be used to handle different mating designs was proposed. Taking the circle design as an example, simulation studies were performed to study the impact of QTL heritability and sample size upon the proposed method. The results showed that under the same heritability, higher QTL detection power and more exact and accurate estimation of parameters could be obtained when three F2 populations were analyzed jointly than when only any two F2 populations were analyzed simultaneously; and higher heritability, especially with larger sample sizes would increase the ability of QTL detection and improve the estimation of parameters. Potential advantages of the method are as follows: firstly, the existing results of QTL mapping in single population can be compared and integrated with each other using this proposed method, so the ability of QTL detection and precision of QTL mapping can be improved. Secondly, owing to multiple alleles in multiple parents, the method can exploit gene resource more adequately, which will lay an important genetic groundwork for plant improvement.

Key words: related population, quantitative trait locus, gene mapping, maximum likelihood estimation