The molecular genotyping of flower development genes and allelic variations in ‘historic’ barley accessions
This is a genetic study of flowering time in cultivated barley with the aim to identify the alleles contributing to rapid flowering and frost resistance. We have genotyped a collection of 23 historic barley varieties for the crucial genes [VRN-1, VRN-2, VRN-3 (HvFT), Ppd-H1, CO, and Vrs1]. We have amplified the polymorphic mutations by PCR-based methods, and sequenced them to identify possible haplotype groups. The row type was not determined of all accessions, but all the Scandinavian varieties were found to carry mutant alleles of Vrs1, that indicates them to be six-row barleys. The deletion of the crucial segment of VRN-1 vernalization contributes dominant spring growth habit. We found haplotype groups 2 and 4 to be dominant in Northern barleys whereas haplotype groups 1 and 5 dominated in south. The presence of dominant allele VRN-2 gene is addressed to floral repression until plants get vernalized. Most of the 23 varieties were found to have deleted allele of VRN-2, which is connected with a spring growth habit. The only four of the accessions that have the dominant allele of Ppd-H1 that contribute flowering are generally from the south of Europe. HvFT and CO genes CO-interact to influence flowering time. CO haplotype grouping suggest a geographical distribution of different alleles but needs more disseminations. Certain HvFT alleles cause extremely early flowering during apex development in the varieties that have deletion of VRN-2 alleles under long days. VRN-3 alleles of 14 varieties were identified.
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