Abstract: This paper deals with the effects of PP333 and GA on bud formation of Longan and rela- tion to endogenous hormones. Results showed that the content of ipA in buds of Longan treated with PP333 was obviously higher than that treated with GA, while the content of GA was gradually decreased from high to low. The both contents treated with GA were contrary. The content of ABA in buds treated with PP333 was lower than that treated with GA. It indicated that high contents of GA and ABA were disadvantageous to bud differentiation and high content of cytokinin(ipA) in buds was advantageous to bud differentiation. Spraying of PP333 could shorten the longth of inflorescence and increase the fruit set and yield.

Key words: Dimocarpus longana

摘要： 研究了 PP-333和 GA对龙眼（Dimocarpus longana Lour.）成花的作用及其与内源激素的关系。结果表明：PP-333处理后，iPA含量明显高于GA的处理，而GA含量则呈现由高到低逐渐下降的趋势；GA处理正好相反；PP-333处理后芽中的ABA含量明显低于GA处理。表明高含量的 GA和 ABA不利于花芽分化，而高含量的细胞分裂素则有利于花芽分化。外施 PP-333可缩短花序长度，提高着果率和增加产量。

关键词: 龙眼, 内源激素, 多效唑（PP333）