Rapid identification and deployment of major genes for flowering time and awn traits in common wheat.

Molecular markers are developed to accelerate deployment of genes for desirable traits segregated in a bi-parental population of recombinant inbred lines (RILs) or doubled haplotype (DH) lines for mapping. However, it would be the most effective if such markers for multiple traits could be identified in an F population. In this study, single nucleotide polymorphisms (SNP) chips were used to identify major genes for heading date and awn in an F population without developing RILs or DH lines. The population was generated from a cross between a locally adapted spring wheat cultivar "Ningmaizi119" and a winter wheat cultivar "Tabasco" with a diverse genetic background. It was found that the dominant allele could make Ningmaizi119 flowered a few months earlier than Tabasco in the greenhouse and without vernalization. The observed effects of the allele were validated in F populations. It was also found that the dominant allele for awnless trait in Tabasco or the recessive allele for awn trait in Ningmaizi119 was segregated in the F population. The allelic variation in the gene relies not only on the DNA polymorphisms in the promoter but also on gene copy number, with one copy in Ningmaizi119 but two copies in Tabasco based on RT-PCR results. According to wheat genome sequences, cultivar "Mattis" has two copies and cultivar "Spelta" has four copies in a chromosome that was uncharacterized (ChrUN), in addition to one copy on chromosome 5A. This study rapidly characterized the effects of the dominant allele and identified the haplotype of in gene copy number in the F segregation population of common wheat will accelerate their deployment in cycling lines in breeding.