Abstrait

Plant Specific Homeobox TaWUS-like Gene Associated with Thousand Grain Weight and Grain Number in Common Wheat

Xuemei Si, Shoaib Ur Rehman, Yuquan Wang, Jian Hou, Chenyang Hao, Tian Li, Xueyong Zhang, Hongxia Liu*

WUSCHEL-related homeobox (WOX) gene is a plant-specific homeobox containing Transcription Factor (TF). WUSCHEL play critical roles in plant developmental events and crop yield. In present study, three copies of TaWUS-like were isolated from chromosomes 5A, 5B and 5D of common wheat. TaWUS-likes were investigated for sequence polymorphism to conduct Marker Trait Association (MTA). Twenty Single Nucleotide Polymorphisms (SNPs) variation and six Inserts and Deletions (InDels) were identified in the promoter (2.0 kb-3.0 Kb) and coding regions among the three copies of TaWUS-like homeologs. For high throughput genotyping, Kompetitive Allele-Specific PCR (KASP) markers were developed. Favored haplotypes were significantly associated with Thousand Grain Weight (TGW) (5B-HapI and 5D-HapI) and Grain Number (GN) (5A-HapI and 5B-HapI) in wheat population collected from China. More sequence polymorphisms presented in TaWUS-like-5B genome than those of TaWUS-like-5A and TaWUS-like-5D genome. Absence of sequence polymorphisms in studied diploid accessions for TaWUS-likes and presence in studied tetra and hexaploid wheat accessions along with polymorphic information content and genetic diversity values suggest that polyploidization events resulted in increased genetic diversity for TaWUS-like-5A while decreased diversity for TaWUS-like-5B and TaWUS-like-5D. Geographic distribution and allelic frequency indicated that the favored haplotypes experienced positive but less intensive selection point towards underutilization of TaWUS-likes in wheat breeding. The developed KASP markers can be instrumental in grain yield improvement by marker assisted selection in wheat breeding programs.