Independent mis-splicing mutations in Ta PHS1 causing loss of preharvest sprouting ( PHS) resistance during wheat domestication.

Preharvest sprouting ( PHS) is one of the major constraints of wheat production in areas where prolonged rainfall occurs during harvest. Ta PHS1 is a gene that regulates PHS resistance on chromosome 3A of wheat, and two causal mutations in the positions +646 and +666 of the Ta PHS1 coding region result in wheat PHS susceptibility. Three competitive allele-specific PCR ( KASP) markers were developed based on the two mutations in the coding region and one in the promoter region and validated in 82 wheat cultivars with known genotypes. These markers can be used to transfer Ta PHS1 in breeding through marker-assisted selection., Screening of 327 accessions of wheat A genome progenitors using the three KASP markers identified different haplotypes in both diploid and tetraploid wheats. Only one Triticum monococcum accession, however, carries both causal mutations in the Ta PHS1 coding region and shows PHS susceptibility. Five of 249 common wheat landraces collected from the Fertile Crescent and surrounding areas carried the mutation (C) in the promoter (−222), and one landrace carries both the causal mutations in the Ta PHS1 coding region, indicating that the mis-splicing (+646) mutation occurred during common wheat domestication., PHS assay of wheat progenitor accessions demonstrated that the wild-types were highly PHS-resistant, whereas the domesticated type showed increased PHS susceptibility., The mis-splicing Ta PHS1 mutation for PHS susceptibility was involved in wheat domestication and might arise independently between T. monococcum and Triticum aestivum. [ABSTRACT FROM AUTHOR]