<正>为研究花芽分化的机理，选择西葫芦种苗在一片真叶期时的子叶为外植体，培养于附加ＫＴ１．０ ｍｇ／ＬＭＳ培养基中，其花芽分化率可达 ６０％；分析西葫芦种苗在一片真叶期时子叶内源激素和多胺含量，发现子叶内源 ＧＡ１／３含量偏低，而 ＺＲｓ含量剧增，同时 ＺＲｓ／ＧＡ１／３、ＡＢＡ／ＧＡ１／３、Ｓｐｄ／Ｐｕｔ、Ｓｐｍ／Ｐｕｔ比值较高。这些内源因素有利于西葫芦子叶花芽分化。

We chose the cotyledous of cucurbit seedlings during first real leaf emerged as explant. KT 1.0 mg/L as a ideal hormone treatment in which a floral experimental system of cucurbit cotyledon was established in vitro. This system showed good repeat and higher ratio of floral bud differentiation (60%). The content of endogenous GA1/3 in the cotyledons is lower during first real leaf of cucurbit seedlings, but ZRs increased significantly, meanwhile ZRs/GA1/3 ABA/GA1/3 Spd/Put Spm/Put showed higher ratio which benefit floral bud differenfiation of cotyledons. So that it is ideal seedlings age to cut cotyledon during first real leaf emerged of cucurbit seedlings.