A genetic examination of early flowering and maturity in Canadian spring wheat

Abstract

Under short-season western Canadian growing conditions, vernalization non-responsiveness is generally considered a preferable spring wheat (Triticum aestivum L.) phenotype, to avoid inconsistent maturity and yield patterns. The objectives of this study were to investigate the genetic factors affecting early flowering and maturity, and related agronomic traits, in a set of five Canadian spring wheat cultivars. The cultivars were first studied under 10- and 16-h photoperiods and 0- and 42-d vernalization treatments. Thereafter, the parents and F1 hybrids from a one-way diallel mating design were grown with and without a 42-d vernalization treatment. Shorter photoperiod delayed flowering time in all cultivars, and increased final leaf number in AC Barrie. Vernalization hastened flowering and decreased final leaf number in AC Foremost and AC Taber. AC Foremost and AC Taber carry at least one different allele, from the rest of the cultivars studied, at the major loci governing vernalization response. Leaf and spikelet number on the main culm, days to anthesis and maturity, tiller number and yield plant-1 were mainly controlled by additive gene action. Narrow-sense heritability was medium to high (0.53–0.93) for final leaf number, days to anthesis, spikelet number and grain yield, but low to medium (0.20–0.71) for days to maturity and tiller number. Selection for early flowering under non-vernalizing conditions may aid in the breeding of (vernalization non-responsive) early-maturing spring wheat cultivars in western Canada. Key words: Diallel cross, earliness, photoperiod, vernalization, Triticum aestivum L.