四个两系杂交水稻穗增重特性分析

Analysis of Panicle Weight Growing of Four Two-line Hybrids of Rice

分析了以培矮64S为母本的4个两系法杂交籼稻的穗增重特性。4个组合的起始质量W0和终极质量A均明显大于三系杂交稻汕优63，表明这4个组合的穗型均较大，为重穗型杂交稻；起始增重势GR0／W0和最高增重速率衄。均明显小于汕优63；穗重活跃增重期为16～24d，长于汕优63，完成穗增重需要35—53d，而汕优63仅需27d。为使两系杂交稻较早出现较高的穗增重高峰，并使活跃增重期延长，而完成整个穗增重的天数缩短，栽培上尤其要注意孕穗期增加茎秆中物质的积累，出穗后保证有充足的光合产物，并预防叶片光合功能早衰。

Panicle weight growing was studied on four two-line hybrids of rice with Peiai64S as their female parents. The initial weight （ W0） and final weight （A） were both higher than those of three-line hybrid （CK）, Shanyou 63, that exhibited large panicles and higher panicle yields. The initial growing rate per weight of GR0/W0 and the maximum growing rate of GRpoi were both lower than those of control hybrid. The active growing period and the full growing period were 16 - 24 d and 35 -53 d, respectively, all longer than those of CK. To get earlier and higher weight growing, and to possess longer active growing days and to shorten the full growth period, it is necessary to increase the accumulation of dry matter in stem and sheath, improve photosynthesis, and prevent leaves from early senescence in the cultivation of such two-line hybrids.