褪黑素引发对Na_(2)SO_(4)胁迫下紫花苜蓿种子发芽特性的影响  

Effects of Melatonin Priming on Alfalfa Seed Germination Characteristics Under Na_(2)SO_(4) Stress

作　　者：刘婧禹 赵海君 欧成明 贾志程 毛培胜[1] LIU Jing-yu;ZHAO Hai-jun;OU Cheng-ming;JIA Zhi-cheng;MAO Pei-sheng(College of Grassland Science and Technology,China Agricultural University,Key Laboratory of Pratacultural Science,Beijing Municipality,Beijing 100193,China)

机构地区：[1]中国农业大学草业科学与技术学院/草业科学北京市重点实验室,北京100193

出　　处：《草地学报》2024年第2期378-385,共8页Acta Agrestia Sinica

基　　金：耐盐碱抗旱苜蓿种子扩繁关键技术研究(2022ZD0401105);国家农业产业技术体系(CARS-34)资助。

摘　　要：试验以紫花苜蓿(Medicago sativa)种子为材料,采用不同浓度的褪黑素(0.05,0.1和0.2 mmol·L^(-1))分别引发种子6 h(记为ML6,MM6和MT6)和12 h(记为ML12,MM12和MT12),以不引发、蒸馏水引发6 h和12 h为对照(记为CK1,CK2-6和CK2-12),探究在Na_(2)SO_(4)胁迫下,褪黑素引发对紫花苜蓿种子发芽和幼苗生长特性的影响,以期筛选有效缓解Na_(2)SO_(4)胁迫的褪黑素引发处理。结果表明,75 mmol·L^(-1)Na_(2)SO_(4)(pH=8.5)胁迫下种子发芽率、发芽势和发芽指数显著下降(P<0.05)。该条件下,与CK1相比,褪黑素引发后苜蓿种子的发芽和幼苗生长能力均有不同程度提高。MT6处理下种子发芽率、发芽势及幼苗根长、苗长和活力指数最高。对MT6幼苗的抗氧化酶活性分析发现,过氧化物酶(Peroxidase, POD)活性显著提高(P<0.05),种子可溶性糖含量显著下降(P<0.05)。综上,0.2 mmol·L^(-1)褪黑素引发6 h紫花苜蓿种子对盐碱胁迫的缓解效应最佳,促进种子发芽和提高幼苗耐盐碱能力。The experiment was conducted with alfalfa(Medicago sativa)seeds,and different concentrations of melatonin solutions(0.05,0.1 and 0.2 mmol·L^(-1))were used to prime the seeds for 6 h(named ML6,MM6 and MT6)and 12 h(marked ML12,MM12 and MT12).Taking non-priming and distilled water priming for 6 h and 12 h as controls(CK1,CK2-6 and CK2-12),the effects of melatonin priming on seed germination and seedling growth characteristics of alfalfa under Na_(2)SO_(4) stress were explored,so as to screen out melatonin priming treatments that can effectively alleviate Na 2SO 4 stress.The results showed that the germination percentage,germination potential and germination index decreased significantly(P<0.05)under the condition of 75 mmol·L^(-1) Na_(2)SO_(4)(pH=8.5).Under this condition,compared with CK1,the seed germination and seedling growth ability of alfalfa were improved at different degrees after melatonin priming.The seed germination percentage,germination potential,seedling root length,seedling length and vigor index were the highest under MT6 treatment.Analysis of antioxidant enzyme activities of MT6-treated seedlings showed that the activity of peroxidase(POD)increased significantly(P<0.05),and the soluble sugar content of seeds decreased significantly(P<0.05).In conclusion,0.2 mmol·L^(-1) melatonin priming for 6 h had the best effect on alleviating salt-alkali stress of alfalfa seeds,promoting seed germination and improving seedling salt-alkali tolerance.

关 键 词：紫花苜蓿 种子引发 褪黑素 Na_(2)SO_(4)胁迫 

分 类 号：S963.223.3[农业科学—水产养殖]