苦瓜离体培养过程中内源激素含量的变化

针对苦瓜（Momordica charantia）离体培养中外植体易于产生愈伤组织而难以再生不定芽的问题，本文采用酶联免疫吸附法，研究了苦瓜组织培养过程中不同发育阶段各外植体内源激素含量的变化，以探讨不定芽分化与激素水平变化之间的关系，以及苦瓜难以再生不定芽的内在制约因素。结果表明：（1）苦瓜外植体中LAA含量较高，而iPAs含量过低，是苦瓜易于产生愈伤组织而不定芽再生困难的主要原因；（2）不定芽的分化与IAA／iPAs的变化有密切的关系；（3）在离体培养过程中，保持外源细胞分裂素类物质（如ZT）的适当浓度并及时继代，有利于苦瓜不定芽的分化。

Changes of Endogenous Hormones in Momordica charantia During in vitro Culture

Because explants of Momordica charantia were apt to form callus rather than adventi- tious buds during in vitro culture, we studied the contents of endogenous hormones in explants at different developing stages to explore the relation between adventitious bud differentiation and endogenous hormones and factors that limit the formation of adventitious buds. Use of enzyme- linked immunosorbent assay (ELISA) revealed that (1) explants had higher content of indole-3-acetic acid (IAA) and lower content of iPAs, which resulted in difficulty in adventitious bud formation; (2) the differentiation of adventitious buds was tightly related with the ratio of IAA to iPAs; and (3) during in vitro culture, adventitious bud differentiation was promoted with a suitable level of cyto- kinin (such as Zeatin) and subculture in time.