Abstract: Different concentrations of ethephon were applied to the street trees Mangifera persiciforma in Xiamen and the flower shedding rate across varying temporal intervals was observed, as well as changes in physiological indicators including endogenous hormone levels (e.g., ABA, IAA), antioxidant enzyme activities (e.g., POD, SOD), and intracellular solute contents. The optimal concentration of ethephon for promoting flower abscission was determined to be within the range of 400 to 600 mg·L–1, with a flower abscission rate approaching 100% and no obvious damage to leaves. After ethephon treatment, endogenous ABA in both leaves and flowers first increased and then decreased. Endogenous IAA in leaves peaked at 1 d post-treatment, then decreased and stabilized, while IAA content in flowers declined gradually. POD activity in leaves increased sharply before slightly declining, whereas in flowers, it exhibited a decreasing trend. SOD activity in leaves showed a trend of first decreasing then increasing, while in flowers, it significantly increased under the influence of ethephon. Malondialdehyde (MDA) content in leaves decreased at 7 d and rebounded at 15 d post-treatment, while in flowers, it increased progressively over time. Soluble sugar content in leaves first decreased then increased, whereas in flowers, it showed an overall downward trend. Changes in soluble protein content in both leaves and flowers were relatively stable. In summary, ethephon at 400–600 mg·L–1 can effectively promote M. persiciforma flower abscission through the regulation of endogenous hormones, antioxidant enzyme activities, and intracellular solutes.

Key words: Mangifera persiciforma, avenue trees, ethephon, flower falling, plant physiology

摘要： 对厦门市区行道树天桃木Mangifera persiciforma喷施不同浓度乙烯利，观测其不同时间落花效果及内源激素含量、抗氧化酶活性、细胞内含物含量等生理指标变化。结果表明，400～600 mg·L–1乙烯利处理促进落花效果最好，花朵脱落率接近100%，且对叶片无明显损伤。经乙烯利处理后，叶片和花朵内源ABA含量先上升后下降；叶片内源IAA含量在处理1 d后最高，随即下落，趋于平稳，花朵内源IAA含量逐渐降低；叶片POD活性大幅上升后稍微回落，花朵POD活性呈下降趋势；叶片SOD活性呈先降后升趋势，在花朵中则受乙烯利影响显著提高；叶片丙二醛含量在处理7 d时下降，处理15 d时回升，在花朵中则随时间推移呈上升趋势；叶片可溶性糖含量先降后升，花朵可溶性糖含量整体呈下降趋势；叶片和花朵中可溶性蛋白含量变化较为平稳。综上，400～600 mg·L–1乙烯利可通过调控内源激素、抗氧化酶活性及细胞内含物，有效促进天桃木落花。

关键词: 天桃木, 行道树, 乙烯利, 落花, 植物生理