Interpreting the genetic basis of silique traits in Brassica napus using a joint QTL network

Abstract

AbstractThe objectives of this study were to decipher the genetic determinants of silique length (SL), number of seeds per silique (SN), thousand seed weight (TSW) and to reveal interactions between trait loci. A double haploid population of 181 lines derived from a cross between two Brassica napus genotypes exhibiting contrasting silique traits was evaluated for silique traits under three environmental conditions. Correlation analysis revealed a significant positive correlation between SL and TSW, a weak positive correlation between SL and SN and a negative correlation between SN and TSW. Quantitative trait loci (QTL) mapping detected 14 additive QTL and 7 QTL pairs with epistatic interactions. Three additive QTL located on LG A9, A1 and A9 had the greatest effect, explaining 51.49%, 23.54% and 27.15% of the phenotypic variance for SL, SN and TSW, respectively. Additionally, the additive × environment and epistatic × environment interaction effects were negligible, indicating the stability of the genetic effects for these QTL. The results will promote a more comprehensive description of the genetic basis of these silique traits in B. napus.