两系杂交稻两优培九穗增重特性及与气象条件的关系

Panicle Weight Gain and Its Relation to Climate Condition for A Two-line Hybrid Rice,Liangyoupeijiu

在南京分期播种分析了两系法杂交籼稻两优培九的穗增重特性及与气象条件的关系。两优培九的穗终极质量为5．17—5．64g，为重穗型杂交稻；4月30日和5月10日播种，穗增重速率由快变慢出现的时间较迟，穗重的快速增加期长达19．1～25．5d，比其他播期长8．3～10．6d。穗增重需要的总天数与生长期平均温度显著正相关，穗生长期平均温度低，则总生长时间缩短。穗重周增量与平均温度及最低温度显著正相关，而与温度日较差呈显著负相关。以4月30日至5月10日播种对两优培九穗重较有利，穗增重速率下降时间较迟，能保持较长的活跃增重期，最终能达到较高的穗重。对于迟播的两优培九，在栽培管理上尤其要注意延迟后期的生理衰老，以延长活跃增重期。

Panicle weight gain and its relation to climate condition were studied using Richards growth equation by different sowing dates with a two-line hybrid, Liangyoupeijiu in Nanjing. Sowed at April 30 and May 10, the final panicle weights were 5.17 -5.64 g, showing big panicle of Liangyoupeijiu. And the date of second inflexion of Richards growth equation, which showed growing speed from rapidness to slow-down, was later, and the active growing days showed 8.3 - 10.6 d longer than those sowed at other three showing dates. The days of panicle weight gain was related significantly with average temperature of the period. Lower temperature would shorten the panicle weight growing days. The weekly increased weight was related significantly with the corresponding average temperature and minimum temperature, while negatively related with temperature fluctuation. The sowing dates of April 30 and May 10, showed longer active growing days and bigger final weights. For late sowed Liangyoupeijiu, it would be important to possess longer active growing days by improving photosynthesis and preventing leaves early senescence.