Effects of plant growth regulators on growth and physiology of alfalfa under saline-alkali stress

LIU Jiaxin; LI Siyu; QU Shanmin

doi:10.13557/j.cnki.issn1002-2813.2025.01.020

Abstract：The experiment aimed to investigate the effects of plant growth regulators on the growth and physiology of alfalfa under saline-alkali stress.The test subject was the'Longmu 801'variety of alfalfa,and the experiment was conducted using potted plants.The experiment investigated the effects of foliar application of different concentrations of gibberellin(GA3),melatonin(MT),naphthalene acetic acid(NAA),and ethylene(ETH)on the growth and physiology of alfalfa under saline-alkali stress.Four concentrations were set for each regulator(T1,T2,T3,T4),which are GA3 group(25,50,100,200 mg/L),MT group(5,10,20,40 mg/L),NAA group(5,10,20,40 mg/L),and ETH group(50,100,200,400 mg/L),with distilled water as the control group(CK group).The regulators were applied on the 45th day after germination,and relevant indices were measured after 14 days.The results showed that different concentrations of plant growth regulators could alleviate the damage caused by saline-alkali stress to alfalfa by regulating the physiological state of alfalfa under stress to a certain extent.Using the membership function method to comprehensively evaluate the measured indices of each treatment,it was concluded that alfalfa in the NAA group at T3 concentration showed the best growth under saline-alkali conditions,followed by the MT group at T2 concentration.The study indicated that 20 mg/L NAA is beneficial for promoting the growth of alfalfa in saline-alkali environments.