【摘要】 为探究外源赤霉素（GA）和褪黑素（MT）对盐、碱和干旱胁迫下白三叶（Trifolium repens）种子萌发、幼苗生长及抗氧化酶的影响，本试验以白三叶‘瑞文德’为试验材料，设置不同浓度(5,10,20,50 mg·L^-1)GA和(1,2,5,12 mg·L^-1)MT的处理，测定了3种胁迫下种子萌发、幼苗生长及生理指标。GA和MT可有效缓解盐、碱和干旱胁迫对白三叶种子萌发及幼苗生长的抑制作用，且随着外源物质浓度的升高，各指标呈先升后降的趋势。其中，20 mg·L^-1 GA显著促进了盐胁迫下白三叶的种子萌发；5 mg·L^-1 MT显著增加了干旱胁迫下白三叶的胚根长和鲜重；20 mg·L^-1 GA显著提高了碱胁迫下白三叶的SOD、POD和CAT活性。通过隶属函数分析得出20 mg·L^-1 GA浸种缓解盐和碱胁迫效果最佳，5 mg·L^-1 MT浸种缓解干旱胁迫效果最佳。因此，在盐、碱和干旱胁迫条件下，使用20 mg·L^-1 GA或5 mg·L^-1 MT浸种能够显著促进白三叶种子萌发和幼苗生长。更多还原

【Abstract】 This study investigated the effects of exogenous gibberellin（GA） and melatonin（MT） on seed germination, seedling growth, and antioxidant enzymes of Trifolium repens under salt, alkali, and drought stress. ‘Ravendel’ was used as experimental material, and different concentrations of(5,10,20,50 mg·L^-1) GA and(1,2,5,12 mg·L^-1) MT were applied. Seed germination, seedling growth, and physiological indexes were measured. The results showed that GA and MT could effectively alleviate the inhibitory effects of salt, alkali, and drought stress on seed germination and seedling growth of Trifolium repens. As the concentration of exogenous substances increased, the indexes exhibited a trend of initially rising and then falling. Specificallly, 20 mg·L^-1 GA significantly promoted the germination of Trifolium repens seed under salt stress, while 5 mg·L^-1 MT significantly increased the radicle length and fresh weight of Trifolium repens under drought stress. Furthermore, 20 mg·L^-1 GA significantly increased the SOD,POD,and CAT activities in Trifolium repens under alkali stress. Membership function analysis showed that 20 mg·L^-1 GA soaking had the best effect in alleviating salt and alkali stress, and soaking in 5 mg·L^-1 MT was most effective in alleviating drought stress. Therefore, soaking seeds in 20 mg·L^-1 GA or 5 mg·L^-1 MT can significantly promote seed germination and seedling growth under salt, alkali, and drought stress.更多还原