Positioning Analysis Of A Major QTL Qph2-3 For Plant Height In Maize

Plant height is one of the important agronomic traits of maize.Previously,the maize inbred line Zheng 58 was used as the recurrent parent,and the chromosome single segment substitution line Z12 and W16 were constructed with Chang 7-2 as the donor parent through genome-wide molecular marker-assisted selection.Z12 and W16 contain a chromosome segment from Chang 7-2 in the bin2.07 region and their plant height is significantly higher than that of Zheng 58.In this study,an F2 population was constructed with Zheng 58×Z12 as materials.Based on the resequencing and bulked segregant analysis(BSA)strategy,the plant height QTL qph2-3 was preliminary mapped.And the qph2-3 was mapped to the Zheng 58×Z12 F2 segregating population and the Zheng 58×W16 F2 segregating population by screening the polymorphic molecular markers in the target interval.Then by reference B73 refgen_v4,the annotation genes present in the localization interval were analyzed.This study provides the useful information for the subsequent gene cloning and functional analysis of maize plant height.The research results are as follows:1.Based on the Zheng 58×Z12 F2 segregating population containing 743 individuals,the QTL Ici Mapping software and 13 pairs of polymorphic molecular markers selected in the target localization interval were used to construct a genetic linkage map.Based on the field height data,the inclusive composite interval mapping was used for for localization analysis.As a result,the plant height QTL qph2-3 was fine-mapped between the In Del molecular markers MPH14 and MPH20,accounting for 20.37% of the phenotypic variation.2.Using 17 pairs of polymorphic In Del molecular markers in the target localization interval and Zheng 58×W16 F2 segregating population containing 1720 individuals.The qph2-3 was mapped between the In Del molecular marker MPH16 and MPH20 with the genetic distance of 2.15 c M and the physical distance of 1.59 Mb.3.The F2 segregating population constructed with Zheng 58×Z12 was used as the experimental material,and the resequencing and bulked segregant analysis(BSA)test method was used.Analysis of the difference in ?SNP between high and low pools,the results show that when the confidence interval is 95%,there are two region above on chromosomes 2 and 6 that exceed the confidence interval,and there may exist QTLs associated with plant height.The plant height QTL of chromosome 2 was mapped in the interval 13.95 Mb,and there were 6 significant significant sites in this region.4.By reference B73 refgen_v4,42 candidate genes were found in this interval.Among these genes,the gene Zm00001d006677 which regulates the brassinosteroid signal may be a candidate gene for qph2-3.