盐胁迫对甜高粱种子萌发及幼苗抗氧化酶活性的影响

Effects of Salt Stress on Seed Germination and Seedling Antioxidant Enzyme Activities of Sweet Sorghum

本研究选择了常规品种和杂交品种的甜高粱品为研究对象,设置了0、50、100、150mmol/L浓度的NaCl溶液,研究了不同梯度盐胁迫对种子萌发、吸水量、幼苗生长和酶活性等影响,结果表明:盐分能够抑制种子的吸水率,随着盐浓度的增加,两个品种的甜高粱种子的吸水率和吸水速率均表现出先升高后降低,50 mmol/L低的盐浓度下能促进种子吸水,杂交品种的吸水率大于常规品品种。随着盐浓度的增加,杂交品种和常规品种的发芽率和发芽指数均降低,低盐浓度50 mmol/L以下对于种子发芽指数的影响较小。胚根和胚芽的生长随着盐浓度的增加而降低,盐胁迫的加剧对于胚芽的生长抑制要大于对胚根长的影响,杂交品种胚根长和胚芽长的降幅要显著低于常规品种。酶活性分析表明幼苗的SOD、POD、CAT的活性均随着盐浓度的升高先升高后降低,当盐浓度为100 mmol/L时,两个品种甜高粱幼苗的SOD、POD、CAT活性均达到了最大值,杂交品种的SOD、POD、CAT活性均大于常规品种,高浓度盐环境对于幼苗叶片CAT活性的影响低于对SOD、POD活性的影响。

In this study,conventional varieties and hybrid varieties of sweet sorghum were selected as the researchobjects,and NaCl solutions with concentrations of 0,50,100,and 150 mmol/L were set to study the effects of different gradients of salt stress on seed germination,water absorption,and seedling growth.The results show that salt can inhibit the water absorption rate of seeds.With the increase of salt concentration,the water absorption rate and water absorption rate of two varieties of sweet sorghum seeds first increase and then decrease,which is as low as 50 mmol/L.The water absorption rate of hybrid varieties is higher than that of conventional varieties.With the increase of salt concentration,the germination rate and germination index of hybrid varieties and conventional varieties decrease.Low salt concentration below 50 mmol/L has little effect on the germination index of seeds.The growth of radicle and embryo decreased with the increase of salt concentration.The intensified salt stress inhibited the growth of the embryo more than it had an effect on the length of the radicle.The decline of the length of radicle and embryo of hybrid varieties was significantly lower than that of conventional varieties.Enzyme activity analysis showed that the activities of SOD,POD,and CAT of seedlings increased first and then decreased with the increase of salt concentration.When the salt concentration was 100 mmol/L,the activities of SOD,POD,and CAT of two varieties of sweet sorghum seedlings all reached The SOD,POD,and CAT activities of hybrid varieties are higher than those of conventional varieties.The effect of high-concentration salt environment on CAT activity of seedling leaves is lower than that of SOD and POD activities.