Abstract:

This research focused on optimizing the parental row ratio and developing suitable field cultivation techniques for hybrid rapeseed production, aiming to provide a theoretical foundation for advancing hybrid breeding technology. The experiment utilized a sterile line (716A) × restorer line (13R) hybrid combination in a two-factor split-plot design, to test six different parental row ratios along with two bolting-stage treatments (topping and non-topping).The results demonstrated that different parental row ratios significantly influenced both agronomic traits and seed production yield in rapeseed. Under single-row paternal line arrangements, seed yields followed the order: T₁₂M₁ > T₁₃M₁ > T₁₄M₁, whereas dual-row paternal configurations exhibited a different hierarchy: T₂₆M₁ > T₂₄M₁ > T₂₈M₁. The bolting-stage topping treatment significantly influenced rapeseed agronomic traits. Compared with the non-topped plants, topped specimens showed average reductions of 9.01% in plant height, 60.03% in effective branching height, 31.19% in primary branch number, and 25.02% in silique number on primary branches. Conversely, secondary branches demonstrated average increases of 28.08% in branch number and 50.52% in silique production. However, the total silique number per plant decreased by 7.03% on average, likely because the increased silique production on secondary branches failed to compensate for the reduction in primary branches. This was accompanied by an average decrease of 6.06% in seeds per silique, ultimately resulting in a 4.98% average reduction in hybrid seed production yield. Based on comprehensive evaluation of all indicators, the T₂₆M₁ treatment achieved the highest yield. In conclusion, under the experimental conditions set in this study, when the parent row ratio was configured at 2:6 and no bolting removal was applied to the female parent during the bud and bolting stage, both the seed production yield and economic benefits of rapeseed reached their optimal levels.

Key words: rape, parental row ratio, topping, agronomic traits, dry matter accumulation, seed production yield, economic benefits