Abstract: Using indica hybrid rice Shanyou 63 and indica/japonica hybrid rice PC311/Zaoxiandang 18 as materials, the effects of exogenous polyamines on grain plumpness under water deficit stress were studied. Putrescine(Put) content in rice leaves and the ratios of Put to spermidine (Spd) as well as spermine (Spm) obviously increasedunder water deficit stress. After applying low concentration of Spd (1 mmol/L) or Spin (0. 5 mmol/L) at heading stage. Put and MDA (malonadehyde) content in the leaves decreased, while Spd and Spm content, photosynthetic rate, endosperm cells, plump-grain percentage and 1000-grain weight significantly increased.

Key words: grain plumpness, photosynthesis, polyamines, water stress

摘要： 以汕优63和PC311/早献党18为材料，研究了不同程度土壤干旱胁迫下水稻叶片中多胺含量变化以及外源多胺对籽粒充实和粒重的影响。在水分胁迫条件下，叶片中腐胺含量和腐胺与亚精胺以及精胺的比值提高。无论在土壤水分充足或水分胁迫条件下，抽穗期施用低浓度Spd和Spm后，叶片中的腐胺和MDA含量降低，而亚精胺和精胺、光合作用速率和籽粒的胚乳细胞数，饱满籽粒百分率以及千粒重显著增加。

关键词: 水分胁迫, 多胺, 光合作用, 籽粒充实