杂交稻开花后根系活力与旗叶衰老和产量形成的关系

The Relation Between Activity of Root System and Flag Leaf Senescence and Yield of Hybrid-rice after Blooming

比较研究杂交水稻和常规水稻开花后旗叶衰老、根系活力及产量形成的关系。结果表明：①水稻开花后旗叶与根系各衰老指标变化关系十分密切。根系伤流强度下降，伤流液中氨基酸含量的下降、ＭＤＡ含量的上升与旗叶叶绿素、可溶性蛋白质含量及ＳＯＤ活性降低、ＭＤＡ含量和膜相对电导度增加正相关。②根叶早衰导致旗叶光合速率迅速降低，籽粒增重缓慢，千粒重低，结实率低。③与常规水稻相比，杂交稻生育后期根叶衰老快。因此，保证杂交稻第２个灌浆高峰并促进籽粒迅速增重，是提高杂交水稻结实率及增产的有效途径。

? The paper studied relation between flag leaf senescence, root system activity and yield of hybrid-rice Sanyou 63 and conventional rice Yangdao 6 after blooming. The results are as follows: ①There are close relation between flag leaf senescence and root system activity;② Early senescence of root system and flag leaf resulted the decrease in photosynthesis rate,retardation of grain filling, reducing the thousand grain weight and setting percentage; ③Comparing with Yangdao 6, the rate of senescence of flag leaf and root system will be speeded up during late growing peiod of Sanyou 63.It is a good way for the increasement of rice setting percentage and yield of hybrid-rice to promote the occurrence of second peaking of filling and increase the grain seed weight.