Envirotyping within a multi-environment trial allowed identifying genetic determinants of winter oilseed rape yield plasticity

Abstract

Abstract A main challenge for rapeseed consists in maintaining seed yield while adapting to climate changes and contributing to environmental-friendly cropping systems. Breeding for plasticity and cultivar adaptation is one of the keys to meet this challenge. Genetic diversity for plasticity is the expression of Genotype x environment interaction. Therefore, we propose to identify the genetic determinant of seed yield G×E interaction for winter oilseed rape using GWAS coupled with a multi-environmental trial and to interpret them in the light of environmental characteristics. Thanks to a comprehensive characterization of a multi-environmental trial using 79 indicators, 4 contrasting envirotypes were defined and used to identify interactive and stable seed yield (SY) QTL. A total of four QTL were detected for SY, among which, QA09 and QC09a, were stable (detected at the multi-environmental trial scale or for different envirotypes and environments); and one, QA07a, was specifically detected into the most stressed envirotype. The analysis of the molecular diversity at QA07a showed a lack of genetic diversity within modern lines compared to older cultivars bred before the selection for low glucosinolate content. The results were discussed in comparison to other studies and methods as well as in the context of breeding programs.