High-density genetic map construction and mapping of the homologous transformation sterility gene (hts) in wheat using GBS markers.

ABSTRACT: BACKGROUND:Homologous transformation sterility-1 (HTS-1) is a novel wheat mutant that exhibits pistillody, the transformation of stamens into pistils or pistil-like structures. More extreme phenotypes of this mutation can have six pistils or pistil-like structures without any stamens in a floret. Thus, HTS-1 is highly valuable for studies of wheat hybrid breeding and flower development. Previous studies have shown that two major genes (Pis1 and hts) control pistillody in HTS-1. The Pis1 gene controls the three-pistil trait in the three-pistil wheat mutant and has been mapped on chromosome 2D, but the hts gene has not been mapped or identified. To do so, we crossed HTS-1 with CM28TP (three-pistil mutant) and constructed a high-density linkage map with the F2 population (200 individuals). RESULTS:The map covered 2779.96?cM, and the genetic distance per chromosome ranged from 37.59?cM to 318.95?cM. The average distance between markers was 1.04?cM. We then mapped hts between GBS-SNP markers 4A_109 and 4A_119, separated by 2.0?cM and 5.2?Mb. To find the candidate genes, the hts region was enlarged to 7.2?Mb, encompassing 752 protein-coding genes. We identified TaWin1 as a possible candidate gene after comparing the 752 genes with 206 common differentially expressed genes between pistillody stamens (PS) versus normal stamens (S) and pistils (P) versus S. Real-time PCR indicated that TaWin1 was highly expressed in HTS-1 during the pistil-and-stamen-differentiating stage, at levels approximately 120 times greater than those in CM28TP. Further analysis indicated that TaWin1 was mainly expressed in HTS-1 PS, supporting its status as a candidate gene of hts. Thus, TaWin1 overexpression probably leads to the transformation of stamens into pistils in wheat. CONCLUSIONS:The results of this study provide a foundation for further research on stamen and pistil development, with implications for wheat-hybrid breeding programs.

SUBMITTER: Yang Q 

PROVIDER: S-EPMC6258151 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature