Evaluation and Screening of Rapeseed Varieties (Brassica napus L.) Suitable for Mechanized Harvesting with High Yield and Quality

Improving seed yield and quality and optimizing plant architecture to adapt to mechanized harvesting are essential strategies for rapeseed industry development in the Yangtze River basin. The present study selected 24 elite rapeseed varieties from the middle region of the Yangtze River basin as materials to investigate the growth period, plant architecture characteristics, lodging resistance, yield, and seed quality across 2 growing seasons. The results showed that plant biomass, silique number per plant, and seed yield showed a significant positive correlation with each other. A high plant growth rate was the prerequisite for early maturity varieties to achieve high yield. The path analysis illustrated that plant architecture can directly affect the seed yield (direct path efficiency = 0.17) or indirectly affect the yield through lodging (indirect path efficiency: -0.37 x 0.30 = -0.11). Therefore, modifying the plant architecture needs to balance the tradeoff between seed yield and lodging. The comprehensive performance of selected genotypes was evaluated by combining D-CRITIC (Distance-based inter-criteria correlation) and membership function methods. From the comprehensive performance across two cropping seasons, the varieties V24, V23, V22, V21, V12, V17, V19, and V20 had substantial potential for mechanized harvesting with high yield and good seed quality. These results provide a theoretical basis for farmers' decisions and breeding of rapeseed suitable for mechanized harvesting in the Yangtze River basin.