Genetic diversity of the HvFT1 flowering gene in Nordic spring barley (Hordeum vulgare L.)
HvFT1 is a gene with an important role in flowering time regulation in barley (Hordeum vulgare L.). It functions as a central integrator for signals of the vernalization, photoperiod and circadian clock pathways and promotes flowering. This is of interest for barley breeders on Iceland, who aim to produce early maturing cultivars. The main objective of this project is to study the genetic diversity of the HvFT1 gene in Nordic spring barley. Sequence variation in this gene is known to influence flowering time in some barley varieties and my aim is to determine whether genetic diversity in HvFT1 contributes to known flowering time differences in Nordic barley lines. To that end, flowering time data was collected and the entire coding region of the HvFT1 gene in 20 different Nordic spring barley lines sequenced. All sequenced traces were manually edited, assembled and aligned in order to detect sequence polymorphisms. HvFT1 sequences from ten additional barley lines were downloaded from NCBI’s GenBank and included in the analyses. A variety of SNPs, insertions and deletions were found in the regulatory and intronic regions, but only a single SNP was discovered in the coding sequence. Sequence variation within the coding sequence is therefore unlikely to influence flowering time significantly in the barley lines studied here. A total of nine alleles were found among the studied barley material. Analysis of sequence polymorphisms, flowering time data and growth habit demonstrated an association between the BGS213- and E40 (Voh2825) alleles and early flowering and spring growth habit. A similar association was discovered between the PE/IAG haplotype and early flowering as well as spring growth habit. This is in accordance with previous studies, that found BGS213 to be the dominant allele in spring barley. The observed early flowering however cannot be explained by sequence variation alone. I propose, that either high copy number variation of HvFT1 or variation at other flowering time genes is likely to significantly influence HvFT1 expression and timing, which could in turn cause the differences in flowering among the studied barley material.
Barley (Hordeum vulgare L.), Flowering time, Genetic diversity, HvFT1
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