Abstract: In order to explore the effects of different plant growth regulators on seedling growth of green onion at seedling stage，the research evaluated the effects of three plant growth regulators（cynanchon，naphthylacetic acid and uniconazole）on the growth of green onion at seedling stage．The results showed that spraying three plant growth regulators could significantly increase the number of roots，stem diameter，seedling strength index and root shoot ratio of green onion seedlings．The plant height of the green onion seedlings treated with cynanchon and uniconazole was significantly decreased，while the plant height of the green onion seedlings treated with naphthylacetic acid was increased．The chlorophyll content and dry weight of the green onion seedlings treated with cynanchon and naphthylacetic acid were increased，while the dry weights of leaves and pseudostems treated with different concentrations of uniconazole were decreased by 7.56%-31.59% and 27.95%-47.33%，respectively，compared to the control at 35 days after treatment．Considering the morphological indexes and dry matter accumulation of the green onion seedlings，the 500 mg·L-1 uniconazole treatment had the best effect on controlling the growth of seedling，and the seedling strength index and root shoot ratio were increased by 111.00% and 91.30% in comparison to the control treatment，respectively．

Key words: plant growth regulator, green onion, seedling；seedling strength index, root shoot ratio

摘要： 为探究不同植物生长调节剂对大葱苗期徒长的控制效果，研究了矮壮素、萘乙酸和烯效唑3 种植物生长调节剂对大葱苗期生长的影响。结果表明，喷施3 种植物生长调节剂均能显著增加大葱幼苗的根系数量、茎粗、壮苗指数和根冠比；矮壮素和烯效唑处理显著降低株高，萘乙酸处理则增加株高；矮壮素和萘乙酸处理的叶绿素含量增加，干质量增加，而喷施不同浓度烯效唑的叶片和假茎干质量在处理后35 d时分别较对照降低7.56%～31.59%和27.95%～47.33%。综合考虑大葱幼苗的形态指标和干物质分配比例，500 mg·L-1 烯效唑处理对大葱幼苗控制徒长的效果最好，壮苗指数和根冠比分别较对照提高111.00%和91.30%。

关键词: 植物生长调节剂, 大葱, 幼苗, 壮苗指数, 根冠比