The Effect of Vernalization Genes on Earliness and Related Agronomic Traits of Spring Wheat in Northern Growing Regions

Abstract

Vernalization response (Vrn) genes play a major role in determining the fl owering times of springsown wheat (Triticum aestivum L.). The objective of this study was to investigate the effect of Vrn genes on fl owering and maturity times and important agronomic traits in a set of reciprocal whole-chromosome substitution lines and eight western Canadian spring wheat cultivars of known Vrn genes, grown over three seeding dates in Alberta, Canada over 2 yr. The genotype carrying spring habit alleles at Vrn-A1, Vrn-B1, and VrnD5 fl owered and matured the earliest, and had the highest grain protein content but the lowest grain yield. Genotypes with spring habit alleles Vrn-A1 and Vrn-B1 were early maturing and high yielding. Genotypes with the spring habit Vrn-D5 allele either singly or in combination with Vrn-A1 were late maturing. The spring habit allele of VrnA1 was not completely epistatic to Vrn-B1 and Vrn-D5 for fl owering or maturity time. The spring habit allele of Vrn-B1, however, was epistatic to that of Vrn-D5 for these traits. In northern wheat growing regions, breeding preference should be given to Vrn genotypes with three spring habit alleles or those with spring habit alleles of VrnA1 and Vrn-B1. Genotypes carrying spring habit Vrn-D5 allele singly or in combination with Vrn-A1 should be planted as early in the growing season as possible to realize their full yield potential.