Analysis of the Structural Organization and Expression of the Vrn-D1 Gene Controlling Growth Habit (Spring vs. Winter) in Aegilops tauschii Coss.

The duration of the vegetative period is an important agronomic characteristic of cereal crops. It is mainly influenced by the Vrn (response to vernalization) and Ppd (response to photoperiod) genes. In this work, we searched for alleles of several known genes of these two systems of response to external conditions in 15 accessions of Aegilops tauschii Coss. (syn. Ae. squarrosa L.), with the aim of studying the impact these alleles have on the vegetative period duration and growth habit. As a result, three allelic variants have been found for the Vrn-D1 gene: (i) one intact (winter type), (ii) one with a 5437 bp deletion in the first intron and (iii) one previously undescribed allele with a 3273 bp deletion in the first intron. It has been shown that the spring growth habit of Ae. tauschii can be developed due to the presence of a new allele of the Vrn-D1 gene. Significant differences in expression levels between the new allelic variant of the Vrn-D1 gene and the intact allele vrn-D1 were confirmed by qPCR. The new allele can be introgressed into common wheat to enhance the biodiversity of the spring growth habit and vegetative period duration of plants.