Effects of melatonin treatment on the growth and photosynthesis of Sola-num tuberosum L.under salt stress

GU Yuqian; SHANG Kaixi; HU Junqing; WANG Wenguan; WEI Hui; LIU Suhui

doi:10.16861/j.cnki.zggc.2025.0224

Abstract：To mitigate the effects of salt stress on the growth and yield of potato,a pot experiment was conducted using the potato cultivar Favorita as the test material.A 150 mmol·L-1 NaCl solution was used to simulate a salt-stressed envi-ronment.Two control groups were set up:Control 1(CK1,non-salt-stressed plants sprayed with deionized)were estab-lished by spraying salt-stressed potato seedlings with melatonin at concentrations of 50,100,150,and 200 μmol·L-1,re-spectively.This study aimed to investigate the effects of different melatonin concentrations on the growth,development,and photosynthetic characteristics of potato under salt stress.The results showed that foliar application of melatonin at var-ious concentrations could improve the salt stress resistance of potato.Compared with CK2,the maximum increases in plant height,stem diameter,and leaf thickness of melatonin-treated potato were 39.05％,66.99％,and 128.07％,respec-tively.For photosynthetic parameters,the maximum increases in chlorophyll content,net photosynthetic rate,stomatal conductance,intercellular CO2 concentration,and transpiration rate were 63.95％,61.08％,34.78％,28.07％,and 55.21％,respectively.Regarding yield-related traits,the maximum increases in aboveground dry mass,aboveground fresh mass,number of tubers per plant,and average single tuber mass were 266.87％,97.96％,150％,and 114.47％,respectively.Among all melatonin treatments,T3(150 μmol·L-1)exhibited the highest increments in all measured indices.In conclu-sion,foliar application of melatonin can enhance the salt stress resistance of Favorita potato,with 150 μmol·L-1 being the optimal concentration.The findings provide an application strategy for growth regulators in potato cultivation on saline-al-kali land and offer theoretical support for the breeding of salt-tolerant potato cultivar.