Research on the Genetic Improvement Effects of Lodging Resistance-Related Traits in Maize Core Germplasm

Lodging is a key factor affecting maize yield and harvestability. This study utilized Reid population baselines and their improved lines as female parents and No-Reid population baselines and their improved lines as male parents to form 48 incomplete diallel crosses. The genetic improvement effects, combining ability, and heterosis of three lodging resistance-related traits (stem tension, puncture strength, and crushing strength at the third internode) were analyzed. Regarding genetic improvement, the results indicated that all three traits were significantly improved in the improved lines compared to the baselines, with improvements increasing in each round. Combining ability analysis showed positive general combining ability (GCA) effects for the improved lines J133A, JM25, JM115, and JM1895 in all three traits, with higher GCA values than the baselines and first-round improved lines. Heterosis analysis revealed the highest advantages for the combinations J133A × JM115 (stem tension), JM25 × JM115 (crushing strength), and J133A × J1865 (puncture strength). These findings suggest that the improved female lines J133A and JM25, along with male lines JM115 and JM1895, not only possess strong lodging resistance but also exhibit high yield potential in the cross J133A × JM115, offering new materials and varieties for maize mechanization.