Abstract: Super high-yielding rice cultivars which were newly bred in China was used to study the relationship between culm traits and lodging resistance. The results indicated that thicker culms were associated with larger panicles; dry matter stored in stem and sheath played an active role in seed development. The breaking-resistant strength of culm was positively correlated with the amount of dry matter stored in stem and thickness of culm. Lodging index was positively correlated with plant height and bending moment, negatively correlated with thickness of culm and breaking-resistant strength; however, there was no relationship between lodging index and internode cross-sectional thickness. The results showed that thicker culms was benefit to larger panicles, so it is important to control plant height properly, breed cultivar of thicker culm, increase dry matter of stem and improve the development of mechanical tissue to strengthen lodging ability.

Key words: Rice, Culm traits, Breaking-resistant strength, Bending moment, Lodging index