Abstract: Effects on chilling on fructose 1,6-diphosphatase (FBPase) of flag leaves in five hybrids Shanyou 63, Shanyou 64, Weiyou 64, Qingyouzao and Xiuyou 57 were investigated. The results indicated that chloroplast FBPase activity of flag leaves in hybrid rice F₁ and their parents at filling stage decreased after low temperature (1℃) treatment. The sensitivity of FBPase to chilling can reflect difference of cold tolerance among these hybrids. The order of cold tolerance was as follows: Japanica type Xiuyou 57, Indica type Qingyouzao, Shanyou 63, Shanyou 64. and Weiyou 64. The cold tolerance of F₁hybrid rice was inherited toward to that of the maternal line. The possible role of FBPase during grain filling and the relationship between FBPase activity of flag leaves and cold tolerance in hybrid rice were discussed.

Key words: Chilling, Filling stage, Flag leaf, Fructose 1, 6-diphosphatase, Hybrid rice, Cold tolerance

关键词: 低温, 剑叶, 杂交稻, 灌浆期, 抗冷性, 果糖1, 6-二磷酸酯酶