中国栽培和野生大豆农艺及品质性状与SSR标记的关联分析--Ⅱ．优异等位变异的发掘

Association Analysis of Agronomic and Quality Traits with SSR Markers in Glycine max and Glycine soja in China:Ⅱ. Exploration of Elite Alleles

在前文研究已检出与农艺品质性状显著关联的SSR位点的基础上,本文进一步对与性状关联位点的等位变异作解析,通过将携带某等位变异的所有材料表型均值与携带无效等位基因(null allele)材料表型均值做比较,估计等位变异的潜在表型效应增量(减量),进一步利用该信息估计位点增效(减效)等位变异的平均效应,鉴别出一批农艺品质性状优异位点、等位变异及携带优异等位变异的载体材料。发现在栽培及野生种质中检出的优异等位变异有同、有异、有互补性。发现关联位点正、负效应等位变异均值间有差异,可根据育种目标性状选择要求,选取适合的位点及相应等位变异。同一标记位点可与多性状关联,其等位变异在不同性状间各有其表型效应的方向和大小;等位变异在相关性状效应上方向、大小的异同解释了性状间正、负相关的遗传原因。关联作图得到的信息可以弥补家系连锁法QTL定位信息的不足,并直接利用等位变异信息进行亲本选拔、组合选配及后代等位条带辅助选择以提高育种成效。

On the basis of our previous results of SSR loci associated with the 16 traits, alleles of loci significantly associated with the traits were analyzed further in the present paper. The phenotypic allele effect was estimated through comparison between the average phenotypic value over accessions with the specific allele and that of accessions with ＂null allele＂, and then the average positive （negative） allele effect （AAE） of a locus was calculated over the estimated phenotypic effects of all positive （negative） alleles. The results showed that a set of elite alleles, loci and their carrier materials were screened out. Among the elite alleles existed in GIycine max and GIycine soja, some were consistent, some inconsistent and some complementary. The phenotypic effects of positive （negative） alleles were different from each other, and therefore, the average positive （negative） effects of a locus were also different from each other, indicating the potential of genetic recombination for breeding purposes. A same marker locus could associate with multiple traits with its alleles performed in their own way in direction and size, and the covariation of a same allele performed in two related traits might be the genetic basis of their phenotypic correlation. In summary, the results implied that association mapping could offer further genetic information complementary to the family-based linkage mapping for the improvement of breeding procedures. In addition, further detailed information on elite alleles and phenotypic effects of the 16 traits were shown in the text.