Proteins and carbohydrates in developing rice panicles were analyzed to see whether these parameters control spikelet number in rice. Two rice cultivars and 2 levels of nitrogen topdressing were used to obtain panicles with different numbers of spikelets. A japonica rice cultivar, Nipponbare, with topdressing (H) had 1.8 times more spikelets per panicle than that without topdressing (L). Moreover, the number of spikelets per panicle in an indica rice cultivar, Takanari, without topdressing was 2.7 times larger than that in Nipponbare-L. Panicles with more spikelets (LP) in Nipponbare-H and Takanari-L showed slower growth than those with few spikelets (SP) in Nippanbare-L in an early stage. LP, however, increased markedly in size thereafter, eventually exceeding SP, in length and fresh weight. Soluble protein content was higher in LP than SP in an early stage, but this difference was hardly detected in a late stage. No clear difference was observed in sugars or starch between LP and SP. Analysis of soluble and insoluble proteins by SDS-polyacrylamide gel electrophoresis showed that bands corresponding to insoluble proteins with a molecular weight about 42 kDa were present at higher intensities in LP than in SP. These results suggest that the spikelet number in rice is controlled by the soluble protein content in an early stage and insoluble proteins with a molecular weight of 42 kDa during panicle development, but not by the carbohydrates in developing panicles.

以粳稻品种武香粳9和籼稻品种H97-322为材料，在基础地力和穗肥施氮相同的条件下，研究了氮素基、蘖肥不同施用水平对水稻氮素吸收利用的影响。结果表明：（1）各处理水稻相对吸氮速率随生育进程而降低，其降低速度随氮素基、蘖肥占总施氮量比重增大而加快。增施氮素基、蘖肥，增加了拔节前吸氮量，但抑制了拔节后吸氮，尤其是显著增加了有效分蘖临界叶龄期至拔节期阶段吸氮量，显著降低了抽穗期至成熟期阶段吸氮量；增施氮素基、蘖肥，虽然有利于拔节前氮素基、蘖肥利用率的提高，但不利于整个生育期的氮素基、蘖肥利用率和总氮肥利用率的提高。（2）氮素基、蘖肥用量适宜，相对吸氮速率平稳减小，各生育阶段吸氮比例协调，氮素利用率和产谷效率协同提高是高产的重要条件。研究还表明目前一般的氮素基、蘖肥用量存在偏高现象。

以越光和武香粳9号为材料研究了不同穗肥施用时期施氮对水稻氨素利用及产量的影响。结果表明：倒1.5叶，倒2.5和0.5叶，倒3.5、2.5和1.5叶施肥提高了花后高效叶片叶绿素含量和含氨率。穗肥施用提高了水稻的产量，倒3.5、2.5和1.5叶，倒3.5和1.5叶，倒2.5叶施肥对增加两品种产量，提高穗肥利用率和生产力作用显著。施用穗肥增产的机制两品种表现不一致：越光主要表现在结实率的提高，武香粳9号主要表现为每穗总粒数的增加。生育期较短的越光穗肥利用率略低于生育期较长的武香粳9号。

以武香粳9号为材料研究了不同穗肥施氮时期对水稻籽粒蛋白质积累的影响。结果表明：穗肥的施用提高了籽粒发育过程中单位干重蛋白质含量，以在倒0.5叶施用氮素穗肥影响最大；随施肥时期的延迟，稻米粗蛋白和谷蛋白含量逐步上升，醇溶蛋白含量逐渐降低；倒2.5叶施氮减少了强、弱势粒中蛋白组分的分布和含量，倒0.5叶施氮与此相反；胚乳蛋白组分在花后15d到25d甚至更晚的时间合成完全。

以武运粳七号为材料，对水稻旱育秧苗和湿润秧苗根系生长的生理物质活性进行了比较研究。结果表明，旱育秧苗总根数、白根数、根系活力及活跃吸收面积较高，根系C/N稍低于湿润秧苗，可溶性糖和硝态氮含量是湿润秧苗的数倍至数十倍，糖和硝态氮的较高积累不仅有利于维持秧苗根系正常的生理活动，也为移栽后秧苗根系生长和新根的发生贮备了充足的营养物质。旱育秧苗移栽前根系中脱落酸（ABA）、吲哚乙酸（IAA）含量高于湿润秧苗，异戊烯基腺嘌呤（iPAs）、赤霉素（GA3）含量低于湿润秧苗，而移栽后3d，IAa、GA3、iPAs含量均高于湿润秧苗。