Genome-wide association for growth habit in bread wheat (Triticum aestivum L.)

The growth habit in bread wheat (spring and winter) is mainly determined by the process of vernalization, regulated by the Vrn genes. Several studies suggest the involvement of other genes in this differential trait. Therefore, the aim of this research was the genomic identification of regions with a possible functional relationship to growth habit. A genome wide association study (GWAS) was performed by using two different approaches: a) FarmCPU (Fixed and random model Circulating Probability Unification) and b) BLINK (Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway), both implemented in the GAPIT package of R. The source was a data set of 25 681 single nucleotide polymorphism loci (SNP's) from 7 757 accessions of T. aestivum stored in the CIMMYT germplasm bank and classified according to growth habit. A total of 593 SNP's markers strongly associated to their growth habit was identified (p < 0.01). But only 70 markers formed association blocks (BA) within 11 chromosomes. As expected, at least one block was located close to the Vrn1 gene of the 5A chromosome. Additionally, 20 genomic regions (BA) were identified with putative functional relationship to growth habit, with response stress proteins involved in acclimation and de-acclimation processes. The findings suggest of new genes implicated in the growth habit for Triticum aestivum and its predictive potential for unclassified genetic accessions.