Study On Relationship Between Morphological And Physiological Traits And Lodging Resistance In Super Hybrid Rice (Oryza Sativa L)

The study on super hybrid rice is very important for ensuring food security in China, and a great breakthrough in the super rice breeding plan has been achieved in our country. But there are some problems in the process of extension and further development, such as lodging and ecological adaptability. This paper focused on the relationship between morphological and physiological traits and lodging resistance with several super hybrids, based on this study, the further experiment of N, K₂O, SiO₂ fertilizer management on lodging resistance and yield in super hybrid rice was conducted. The main results were as follows:1 , On the side of relationship of morphological traits and lodging resistance, positive effect existed between plant height, fresh weight per culm, length of second internode from the top and lodging index, but negative effect existed between breaking strength, minimal culm diameter and lodging index. So more plant height, more biomass, longer second internode from the top were not helpful for improving lodging resistance, but huger breaking strength, wider minimal culm diameter were helpful for improving lodging resistance. The absolute value of direct path coefficient of morphological index to lodging index was in the sequence of fresh weight per culm, breaking strength, plant height; minimal culm diameter and length of second internode from the top.2, On the side of relationship of physiological traits and lodging resistance, the dry matter transfer rate was lower in some combinations with better lodging resistance, while relatively higher in those combinations with weaker lodging resistance though more the dry matter weight in the culm and sheath. The correlation coefficients between total content of K, Si, coarse fiber in culm and lodging index were not significant, but the direct path coefficient of the three indices and indirect path coefficient between three indices were consistently negatively effective on lodging index. So it was necessary to keep higher content of K, Si, coarse fiber in the culm for improving lodging resistance at late growth stage.3, There were most significant or more significant difference for the yield and yield components in super hybrid rice between years and between combinations, and those differences...