水稻不同粒位籽粒的结实能力

供试品种为武育粳２号，设分蘖肥、促花肥、保花肥，粒肥及水分等处理，研究其对一、二次枝梗各粒位籽粒粒重和饱粒率的影响。结果表明：（１）施氮量、施肥时期、土壤水分状况对不同粒位籽粒饱粒率和粒重的影响程度不同，（２）在一次枝梗六个粒位中，第１粒的饱和率既有最高的，也有最低的，还有处于２－５位，其它粒位也是如此，二次枝梗籽粒亦有类似趋势；（３）二次枝梗各粒位籽粒的粒重顺序与开花早迟一致，一次枝梗籽粒除第二

Ripening Abilities of Spikelets on Different Positions of Panicle in Rice (Oryza sativa L.)

Experiments with nitrogen application dates and rates as well as water supply levels were carried out with Japonica rice Wuyujing No. 2 in pot. Effects on fulfilled grain percentage and grain weight in different grain positions were analysed. Results showed that: 1. Effects on the fulfilled grain percentages and grain weights varied with grain positions. 2. The fulfilled grain percentage of the Ist grains on primary branches might range from the highest to lowest among the six grain positions. The same trend was observed in other grains on primary branch and that on secondary branch. 3. Sequences of grain weight on different positions of secondary branches was identical in order of their flowering, and that of primary branch was sub-jected to the treatments except the 2nd grain.