Using Selective Genotyping And Residual Heterozygous Line To Identify Soybean Growth Period And Branch Number QTL

The growth period and branching number are both important agronomic traits for soybean production.Consequently,it is of great theoretical and practical significance to mapping the QTL loci about these two traits.For mapping the growth period related QTL,an separation population was constructed with a cultivar Hedou14?paternal parent?and a wild soybean ZYD02810?maternal parent?.In the F₂ population,two QTLs related to growth period were preliminary mapped at Satt307?121.27 cM?on C2 linkage group and Satt718?73.79cM?on C1 linkage group by selective genotyping method.Furtherly,the above results were tested in the F₂: 3 residual heterosis population.The results showed that the QTL at Satt307 locus could be validated by different methods,while the QTL at Satt718 locus could not.Additionally,the sequencing results demenstrated that there was no difference between the parents for the reported genes,E1 E4.So,the loci about growth period trait in the research are different form them.For mapping branching number related QTL,the separation population was constructed by crossing low-branching cultivar Jihuang-13 with hign-branching landrace,Xiaoheidou.In 2012,Xu Yanping used selective genotyping of low-branching phenotypic extreme in the F_2:3 population to map branching number QTL.And in 2014,another mapping was further carried out in two extremes in F₂:4 population by selective genotyping approach.The results showed that in 2014,by comparing the allele frequencies in the two tails of F₂:4 popultion,two new QTLs were mapped on linkage group B2 and F at BARC13-1845 and BARC 14-1214 respectively.The QTL mapped on linkage group L at BARC19-1222?71.32cM?in 2012 could not be identified in 2014.Compared with the reported results,the two QTLs detected in2014 might be two new ones.The results in this paper would set a foundation for further fine mapping the related QTL and marker assisted selection in plant breeding.