Genetic Analysis of Oil Yield, Seed Yield, and Yield Components in Rapeseed Using Additive Main Effects and Multiplicative Interaction Biplots

Abstract

Rapeseed (Brassica napus L.) is regarded as one of the most important oilseed crops worldwide. An experiment was conducted to quantitatively examine the genetic parameters of oil yield, seed yield, and yield components for rapeseed by using a half diallel of nine rapeseed cultivars. The 36 F1 hybrids, their parents, and four other commercial varieties were planted in breeding nurseries in 2008 and 2009. During the growing season, the number of pods per plant (NPP), number of seeds per pod (NSP), pod length (PL), 1000 seed weight (SW), harvest index (HI), seed yield (SY), oil percent (OP), and oil yield (OY) were measured. The data were analyzed with the additive main effects and multiplicative interaction (AMMI) model and its biplots. The first two principal components (IPC1 and IPC2) were used to create a two‐dimensional biplot. IPC1 accounted for 28.7% (SW in 2008) to 48.9% (OP in 2009) of the sum of squares of the male by female (M × F) interaction, while IPC2 accounted for 18.3% (PL in 2009) to 31.6% (number of seeds per pod in 2008) of the sum of squares of the M × F interaction. Two heterotic groups were identified for OY, and six between‐group crosses, that is, [Talaye, Modena, Opera] × [Fornax, Orient], would provide maximum heterosis for this trait. The AMMI analysis with the half diallel method identified not only the general combining ability (GCA) and specific combining ability (SCA) effects but also the F1 crosses whose offspring may display heterosis in their offspring. The results can be used to design efficient breeding strategies in rapeseed.