2020 Volume 89 Issue 2 Pages 119-125
We investigated culm strength associated with lodging resistance of 18 main wheat cultivars raised in each region of Japan. “Yumechikara” had the smallest lodging index and was considered to have the highest lodging resistance among 18 cultivars. “Yumechikara” which had the largest bending moment at the breaking point of the basal internode with leaf sheath exhibited large bending stress and section module. “Yukichikara”, “Kinunonami”, “Ayahikari” and “Chikugoizumi” also had a large bending moment at the breaking point. Among them, “Yukichikara” and “Chikugoizumi” had a large bending stress and medium section module, while “Kinunonami” and “Ayahikari” had medium bending stress and large section module. In this study, cultivars that were bred in Hokkaido region had larger cross sectional area and spikelet number per spike than cultivars that were bred in Kyushu region, while cultivars bred in Kanto region had intermediate values. It was suggested that “Yumechikara” had high resistance to both stem bending and breaking lodging, and the trait related with culm strength was different in each breeding area. Furthermore, among cultivars with a large bending moment at the breaking point, there were cultivars with large bending stress and medium section module, and cultivars with medium bending stress and large section module. It was considered possible to raise a greater cultivar with lodging resistance by crossing between cultivars with such different traits.