中文摘要：

以4个超级稻品种[两优培九和II优084（杂交籼稻）、淮稻9号和武粳15（粳稻）]为材料,2个高产品种[汕优63（杂交籼稻）、扬辐粳8号（粳稻）]为对照,测定了结实期强、弱势粒中腐胺（Put）、亚精胺（Spd）和精胺（Spm）浓度和灌浆速率,分析了它们之间的关系并用化学调控的方法进行了验证。结果表明,强势粒的最大灌浆速率、平均灌浆速率和糙米重,超级稻品种与对照品种差异较小,弱势粒的灌浆速率和粒重表现为超级稻品种显著低于对照品种。灌浆期强、弱势粒的Put、Spd和Spm浓度变化均成单峰值曲线。Put的峰值浓度和平均浓度,弱势粒高于强势粒。Spd和Spm峰值浓度和平均浓度,弱势粒显著低于强势粒,超级稻品种低于对照品种。籽粒平均灌浆速率和糙米重与Put浓度呈极显著负相关,与Spd和Spm浓度以及Spd/Put和Spm/Put呈极显著正相关。灌浆初期对稻穗喷施Spd和Spm,增强了弱势粒中蔗糖合成酶、ADP葡萄糖焦磷酸化酶和可溶性淀粉合成酶活性,提高了弱势粒灌浆速率、结实率和粒重,喷施Put或多胺合成抑制剂（MGBG）的结果则相反。说明多胺参与水稻籽粒灌浆的调控,超级稻品种弱势粒较低的Spd和Spm浓度及较低的Spd/Put和Spm/Put值是其灌浆速率小、粒重轻的一个重要生理原因。

英文摘要：

Success in super rice breeding has been considered a great progress in rice production in China. However, many un-filled inferior spikelets limit the realization of great yield. As polyamines have been frequently described as endogenous plant growth regulators or intracellular messengers mediating physiological processes, this study investigated whether and how poly-amines are involved in the regulating post-anthesis development of rice spikelets. Four super rice cultivars, Liangyoupeijiu and II you 084 （indica hybrids）, Huaidao 9 and Wujing 15 （japonica）, and two high-yielding check cultivars, Shanyou 63 （indica hybrid） and Yangfujing 8 （japonica）, were field grown. Concentrations of putrescine （Put）, spermidine （Spd） and spermine （Spm） in both inferior and superior spikelets during the grain filling period and grain filling rate were determined. The relationship between polyamine concentrations and grain filling rate were analyzed, and chemical regulators were applied to verify the roles of poly-amines in grain filling. The results showed that the maximum grain filling rate, mean grain filling rate, and brown rice weight for superior spikelets showed small difference between the super rice and check rice, but those of inferior spikelets were significantly lower for super rice than for check rice cultivars. Changes in concentrations of polyamines in grains exhibited single peak during the grain filling period. The peak and mean concentrations of Put were greater in inferior than in superior spikelets. The peak and mean concentrations of Spd and Spm were greater in the superior than in the inferior, and greater in the check rice than in the su-per rice. The mean grain filling rate and brown rice weight were negatively and very significantly correlated with the Put concen-trations, and positively and very significantly correlated with Spd and Spm concentrations, Spd/Put, and Spm/Put. Application of Spd or Spm to panicle at the early grain filling stage significantly enhanced activities