抗坏血酸提高棉花种子萌发耐盐性及其生理机制

Improvement of Salt Tolerance in Cotton Seed Germination by Ascorbic Acid and Its Physiological Mechanism

本研究以新疆主栽棉花品种‘新陆早61号’为材料,旨在探讨抗坏血酸(AsA)浸种对提高棉花种子萌发期耐盐性的效果及其生理机制。通过分析不同类型盐胁迫(NaCl、Na_(2)SO_(4)和Na_(2)CO_(3)+NaHCO_(3))下,抗坏血酸(AsA)浸种对棉花种子(棉种)主要发芽特性和生理指标的影响。结果表明,棉种的萌发随盐胁迫浓度升高而下降;但在AsA浸种处理后,棉种萌发特性显著增强,其中发芽率分别比对照提高了55.32%、56.10%和44.0%。最佳AsA浸种浓度分别为0.10 mmol/L(NaCl和Na_(2)SO_(4))和0.15 mmol/L(Na_(2)CO_(3)+NaHCO_(3))。此外,盐胁迫萌发过程中AsA浸种提高了棉种SOD、POD、CAT抗氧化酶的活性,增强了可溶性蛋白和可溶性糖的含量,同时降低了MDA和H_(2)O_(2)的水平。研究表明,AsA浸种通过增强抗氧化酶活性、增加渗透物质含量和减少膜脂过氧化,有效提升了棉花种子的耐盐性。

The study aims to explore physiological mechanisms of salt tolerance in cotton during seed germination stage.Using‘Xinluzao NO.61’,a major local cotton variety,as the test material,the effects of ascorbic acid(AsA)soaking on key germination characteristics and physiological indicators of cotton seeds were analyzed under different types of salt stress.The results showed that the germination of cotton seeds decreased with increasing salt stress concentration;Under NaCl,Na_(2)SO_(4),and Na_(2)CO_(3)+NaHCO_(3) stress,the soaking with AsA enhanced the germination characteristics of cotton seeds,among them,the germination rate of cotton seeds increased the most,increasing by 55.32%,56.10%,and 44.0%compared to the control,respectively,and the optimal AsA soaking concentration for improving salt tolerance was selected as 0.10 mmol/L,0.10 mmol/L,and 0.15 mmol/L;during the germination process under salt stress,the activities of SOD,POD and CAT,and the contents of soluble protein and soluble sugar in cotton seeds soaked with AsA increased,while the content of MDA and H_(2)O_(2) decreased,and all showed significant differences from the control group.It is concluded that AsA soaking can improve the salt tolerance of cotton seed during germination,as it enhances the main antioxidant enzyme activity,increases the content of osmotic substances,and alleviates membrane lipid peroxidation of cotton seed.