Fine Mapping Of Soybean Recessive Dwarf Gene 19-DW

Plant height is an important agronomic trait of soybean,which directly affects the yield,quality and cultivation model.The high-yield soybean technology system proposed by Copper et al,which is based on the narrow-row or dense-plant cultivation mode of dwarf or semi-dwarf varieties,has greatly enhanced the soybean yield in the United States at that time.Chinese breeders have also improved a number of semi-dwarf varieties and achieved high yields.However,due to the long cycle and low efficiency of traditional breeding,the selection and utilization of dwarf varieties are limited.It is an effective way to solve this problem by creating excellent dwarf germplasm,excavating dwarf functional genes,and applying them to molecular breeding.In our previous research,a genetically stable dwarf strain,named F02 derived from the cross of Chinese flat stems and American flat stems was improved.The BC1F2 segregated population was constructed using F02 and Chinese flat stems as parents.Genetic analysis showed that the population of high and short plants numbers was in accordance with the 3:1 Mendelian separation law,indicating that the dwarf traits was controlled by one recessive single genes or linkaged major genes.Using bulking segregated analysis(BSA)method,the dwarf gene was mapped on the intervals 30,735bp-399,985 bp and 44,947,812bp-49,497,950 bp of 19 chromosomes with the length 99.25 kb and 4.55 Mb respectively.The mapping region contained 299 non-synonymous mutant SNPs and 141 non-synonymous mutant genes.Using the SSR marker and the newly developed dCAPS marker,the dwarf gene was further finely mapped into the 44,975,289bp-46,765,417 bp range,with a total length of 1.79 Mb and containing 49 non-synonymous mutant genes.In order to further identify candidate genes,the expression levels of 49 candidate genes were analyzed between two parents.The results indicated that there were 20 genes had significant difference.Among them,Glyma.19G192400,Glyma.19G193900,Glyma.19G195800,Glyma.19G200900,Glyma.19G203800,Glyma.19G203900,Glyma.19G205400,Glyma.19G206100 have regulatory roles in plant growth and development,funciton annotation showed that Glyma.19G206100 have high homology with auxin response factor,so this gene was listed as a key candidate gene.