ernalization of Wheat and Genetic Determinism of the Vernalization Reaction

Winter wheat sown in the spring does not manage to produce grains. Vernalization is necessary for wheat to pass from the vegetative phase to the generative phase. This happens in the same time with wheat “quenching”. Studies show that vernalization can occur during germination, during plant growth or during seed formation and at the full maturity of the grains. Other research emphasizes that vernalization of wheat corresponds to the accumulation of total phytochrome in the vegetative apex and to the accumulation of this pigment in the leaves, and the phenomenon of quenching is achieved by a transformation of the total phytochrome in less sensitive forms to dehydration of cells produced by frost. Vernalization of cultivated wheat is mainly controlled by three loci of the VRN1 gene, VRN-A1, VRN-B1 and VRN-D1 located in the middle of the long arms of chromosomes 5A, 5B and 5D respectively. Spring wheat has alleles of the VRN1 gene that reduce or eliminate the vernalization requirement. As result of research there was identified a fourth gene that controls wheat vernalization requirement (VRN 4). They have shown that this gene is a transcribed copy of the VRN1 gene. The study of Kippes et al. (2015) highlights the importance of the VRN1 gene as a regulator of vernalization and as a major gene that controls adaptation strategies and the wheat life cycle.