Abstract Understanding genotype and environment interaction (G × E) and the association between yield and phenological, architectural and physiological traits plays a crucial role in successful canola breeding and agronomic management. We investigated yield performance of 20 open-pollinated and hybrid canola across multiple environments over five years and its association with these traits. Heterogenic genetic variance and genetic correlation among the environments demonstrated significant G × E interactions in yield, biomass, but not in harvest index (HI). Flowering time, biomass at maturity and HI are the three most important traits underlying the G × E interaction. Principal component analysis (PCA) based on the yield across the environments identified two mega-environments (the low/medium rainfall zone (LMRZ) and the high rainfall zone (HRZ)) and four genotype clusters (early-flowering, late-flowering, average performing, and broadly adapted varieties). Early flowering genotypes were better adapted to the LMRZ mega-environment and late-flowering ones to the HRZ mega-environment. Despite the G × E interaction, a group of hybrid varieties were identified as broadly adapted, producing either the highest or similar yield to specifically adapted varieties. The genotype by trait PCA revealed that yield was positively associated with biomass and HI but negatively with flowering time in the LMRZ mega-environment. In contrast, yield was positively associated with increased biomass, late-flowering but negatively with HI in the HRZ mega-environment. In both mega-environments, HI was negatively correlated with delay in flowering and increased plant height and biomass. Reducing plant height in late flowering hybrid varieties offers a solution to the trade-off between biomass and HI. It can have the potential to increase yield by increasing HI while maintaining biomass in the HRZ mega-environment.

中文翻译：

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澳大利亚西南部降雨区油菜籽产量及其与物候、建筑和生理特征的关联

摘要 了解基因型和环境相互作用 (G × E) 以及产量与物候、建筑和生理性状之间的关联在成功的双低油菜籽育种和农艺管理中起着至关重要的作用。我们调查了 20 种开放授粉和杂交油菜在 5 年内在多种环境中的产量表现及其与这些性状的关联。环境之间的异源遗传变异和遗传相关性在产量、生物量方面表现出显着的 G×E 相互作用，但在收获指数 (HI) 中没有。开花时间、成熟生物量和 HI 是 G × E 相互作用背后的三个最重要的性状。基于跨环境产量的主成分分析 (PCA) 确定了两个大型环境（低/中降雨区 (LMRZ) 和高降雨区 (HRZ)）和四个基因型簇（早花、晚花、表现一般，适应范围广的品种）。早花基因型更适应 LMRZ 大环境，晚花基因型更适应 HRZ 大环境。尽管 G × E 相互作用，一组杂交品种被确定为广泛适应的，与特别适应的品种产量最高或相似。性状 PCA 的基因型显示，在 LMRZ 大环境中，产量与生物量和 HI 呈正相关，但与开花时间呈负相关。相反，产量与生物量增加呈正相关，晚花但在 HRZ 大环境中对 HI 不利。在这两种大型环境中，HI 与开花延迟和植物高度和生物量增加呈负相关。降低晚花杂交品种的株高为生物量和 HI 之间的权衡提供了解决方案。它有可能通过增加 HI 来增加产量，同时保持 HRZ 大环境中的生物量。