This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.
Phenotypic and metabolic variation among spring Brassica napus L. genotypes during heat stress
Heat stress can often limit the yield of Brassica napus L. grown in Canada, due to the often unavoidable concurrence of high temperatures and flowering. Ten B. napus inbred genotypes, an open-pollinated B. napus commercial cultivar and a B. juncea genotype were grown in a greenhouse and subjected to two temperature regimes in a growth chamber (control temperature of 22/10 C and high temperature 31/14 C (day/night) for 14 days during flowering). Floral buds were sampled at the end of the 14 day treatments and an untargeted metabolomic assessment was completed using GC/MS. Flower duration, flower number, pod number, biomass, seed number and seed weight were collected. Yield was reduced by 55 % in the heat treatment during the winter and 41 % during the subsequent fall experimental run. Of the 12 genotypes, five were classified as heat-tolerant and four were classified as susceptible based on the calculated heat susceptibility index across two experiments. Twenty-five metabolic markers were identified that discriminated between the heat-tolerant and susceptible genotypes exposed to the heat treatment. The variation identified within this set of germplasm has provided evidence that variation exists within B. napus to enable genetic gain for heat tolerance.
CP17259 Accepted 12 December 2017
© CSIRO 2017