Allelic Variation Analysis at the Vernalization Response and Photoperiod Genes in Russian Wheat Varieties Identified Two Novel Alleles of Vrn-B3.

Alina Berezhnaya,Alina Berezhnaya,Irina Leonova,Antonina Kiseleva,Elena Salina

doi:10.3390/biom11121897

Alina Berezhnaya, Alina Berezhnaya + Show 3 more

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https://doi.org/10.3390/biom11121897

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Abstract

Heading time is an important agronomic trait affecting the adaptability and productivity of common wheat. In this study, 95 common wheat varieties from Russia and the late-maturing breeding line ‘Velut’ were tested for allelic diversity of genes having the strongest effect on heading. In this research, allelic variation at the Ppd-D1, Vrn-A1, Vrn-B1, Vrn-D1, and Vrn-B3 loci was tested. The Vrn-B1 and Vrn-B3 loci provided the largest contribution to genetic diversity. We found two novel allelic variants of the Vrn-B3 gene in the studied varieties. Ten varieties carried a 160 bp insertion in the promoter region, and the breeding line ‘Velut’ carried a 1617 bp insertion. These alleles were designated Vrn-B3e and Vrn-B3d, respectively. The analysis of the sequences showed the recent insertion of a retrotransposon homologous to the LTR retrotransposon (RLX_Hvul_Dacia_ RND-1) in the Vrn-B3d allele. Plants with the Vrn-B3e and the ‘Velut’ line with the Vrn-B3d allele headed later than the plants with the wild-type allele; among these plants, ‘Velut’ is the latest maturing wheat variety. Analysis of the gene expression of two groups of lines differing by the Vrn-B3 alleles (Vrn-B3d or vrn-B3) from the F2 population with ‘Velut’ as a parental line did not reveal a significant difference in the expression level between the groups. Additional research is required to study the reasons for the late maturation of the ‘Velut’ line. However, the studied wheat varieties could be used as a potential source of natural variation in genes controlling heading times.

Highlights

The yield potential of wheat largely depends on the duration of each of the developmental phases
Ninety-five common wheat varieties and the ‘Velut’ line were characterized for the allelic composition of vernalization and photoperiod alleles (Table S1)
Allelic diversity within genes controlling flowering time is one of the most important factors contributing to the adaptability and productivity of wheat. Allelic variation at these loci was tested for 95 spring wheat varieties grown in Siberia

Summary

Introduction

The yield potential of wheat largely depends on the duration of each of the developmental phases. The heading time of wheat is mainly determined by the allelic composition of vernalization (Vrn) and photoperiod response (Ppd-1) genes [1]. Under the control of the Vrn-1, Vrn-2, and Ppd-1 genes, Vrn-B3 is expressed in leaves and moves to the shoot apical meristem and promotes flowering [2,3,4]. The Vrn-1 genes controlling the wheat vernalization requirement were mapped to homologous chromosome group 5 [5]. The presence of at least one dominant Vrn-1 allele in hexaploid wheat results in spring growth habit. The dominant Vrn-A1 is epistatic to Vrn-B1 and Vrn-D1, which are associated with a slight vernalization response [6]. Genetic variation at the Vrn-1 loci is one of the most important factors affecting heading time in wheat

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