草业学报2026，Vol.35Issue(8)：55-64,10.DOI:10.11686/cyxb2025328
低磷胁迫下外源褪黑素对紫花苜蓿幼苗内源激素及有机酸的影响
Effects of exogenous melatonin on endogenous hormones and organic acids in alfalfa seedlings under low-phosphorus stress
摘要
Abstract
This study aimed to investigate the effects of exogenous melatonin(MT)on endogenous hormones and organic acids in alfalfa(Medicago sativa)seedlings under low-phosphorus stress.Two alfalfa varieties,one tolerant to low-phosphorus conditions(7890)and one sensitive to phosphorus deficiency(15578),were subjected to seven treatments:normal phosphorus(1.0 mmol·L⁻¹,NP),low phosphorus(0.01 mmol·L⁻¹,LP,with KH₂PO₄ as the phosphorus source),and LP combined with root irrigation with MT at concentrations of 30,60,90,120,and 150 μmol·L⁻¹.Fourteen characteristics of alfalfa seedlings were evaluated:plant height,leaf area,aboveground biomass,underground biomass,leaf relative water content,and root zeatin,auxin,gibberellin acid,oxalic acid,lactic acid,citric acid,succinic acid,fumaric acid,and malic acid contents.The values of these 14 characteristics initially increased and then decreased with increasing MT concentration,reaching a maximum in the 90 μmol·L-1 MT treatment.For alfalfa variety 7890,compared with the plants under LP stress,those in the 90 μmol·L-1 MT treatment showed increases of 16.55％,34.62％,32.41％,86.78％,15.77％,10.45％,49.56％,15.74％,37.34％,20.05％,61.21％,50.14％,11.50％,and 39.06％,respectively,in the above 14 measured characteristics.For alfalfa 15578,these values were increased by 26.75％,32.00％,44.88％,108.91％,27.45％,28.64％,70.21％,107.20％,29.50％,9.17％,55.24％,56.09％,12.00％,and 30.71％respectively,in the 90 μmol·L-1 MT treatment compared with the LP treatment.Abscisic acid content exhibited a trend of initially decreasing then increasing with rising MT concentrations,reaching its maximum in the 150 μmol·L-1 MT treatment.The membership function analysis indicated that the 90 μmol·L-1 MT treatment exerted the strongest effect to alleviate the symptoms of low-phosphorus stress in alfalfa plants.The trends in the responses of variety 7890(tolerant to low phosphorus)and variety 15578(sensitive to low phosphorus)to MT were the same,but variety 15578 showed a greater level of improvement with MT treatment under LP stress,indicating that the alleviating effect of MT is greater for materials that are sensitive to low-phosphorus conditions.The results of this study provide a theoretical basis and technical approach for using MT to improve the phosphorus-use efficiency of crops.关键词
紫花苜蓿/褪黑素/低磷胁迫/内源激素/有机酸Key words
alfalfa/melatonin/low phosphorus stress/endogenous hormone/organic acid引用本文复制引用
黄兆鹏,何蓉,南丽丽,刘佳乐,杨文科..低磷胁迫下外源褪黑素对紫花苜蓿幼苗内源激素及有机酸的影响[J].草业学报,2026,35(8):55-64,10.基金项目
甘肃省重大专项(25ZDNA005)和财政部和农业农村部:国家现代农业产业技术体系(CARS-34)资助. （25ZDNA005）
