以3个中国南瓜自交系为材料，探究乙烯利和乙烯抑制剂硫代硫酸银(STS)喷施幼苗期茎芽组织对南瓜花性别分化的影响，以及叶片乙烯合成和受体基因（ACO、ETR）对该处理的响应。结果表明，与未处理植株相比，乙烯利处理使乙烯合成酶基因ACO和乙烯接受体基因ETR的表达水平升高；调查20节内的花性别分化发现，乙烯利处理显著降低了第一雌花节位，并增加了雌花数量，其对雄花数量的影响在不同自交系中存在差异；相反，STS处理抑制了ACO和ETR的表达，显著延迟了第一雌花的产生，增加了植株20节内的雄花数量，降低了雌花数量。说明乙烯利和乙烯抑制剂STS处理既能影响乙烯的合成，也能影响乙烯的响应；乙烯利对雌花的促进作用和STS对雌花的抑制作用可能与其诱导或抑制了乙烯合成及响应基因的表达有关。

Three inbred lines of Cucurbita moschata were used as materials to investigate the effect of spraying ethephon and ethylene inhibitor STS on shoot meristem during seedling stage on sex differentiation,as well as the response of ethylene synthesis and receptor genes (ACO,ETR) to this treatment.The results showed that,compared with untreated plants,ethephon improved the expression levels of ACO and ETR.Furthermore,through investigating the sex differentiation within 20 nodes,it was found that the first female flowers node decreased and the number of female flowers increased significantly. Its effects on male flowers number varied with different inbred lines.In contrast, STS inhibited the expression of ACO and ETR,delayed the first female flowers emerging,increased the number of male flowers, and decreased the number of female flowers.The results indicate that ethephon and ethylene inhibitor STS can affect both ethylene synthesis and ethylene response genes,the promoting effect of ethephon and the inhibiting effect of STS on female flowers may be related to its induction or inhibition on the expression levels of ethylene synthesis and response gene.