摘要
为探究PEG-6000和NaCl溶液模拟干旱和盐胁迫对唐古特大黄种子萌发的影响,以及外源AsA对干旱和盐胁迫的缓解效应,本研究采用质量分数 5%、10%、15%、20%、25%PEG-6000 溶液和 0.05、0.10、0.15、0.20、0.25 mol/L NaCl溶液培养唐古特大黄种子,筛选对种子萌发抑制作用最强的PEG-6000 溶液和NaCl溶液浓度;同时,施加不同浓度的AsA,通过测定种子的发芽率、发芽势和发芽指数,揭示外源AsA对模拟干旱和盐胁迫下唐古特种子萌发的影响.结果表明,随着模拟干旱和盐胁迫的PEG-6000 溶液和NaCl溶液浓度的增加,唐古特大黄种子的发芽率、发芽势、发芽指数等指标呈下降趋势,其中 25%的PEG-6000 和 0.25 mol/L NaCl溶液对种子萌发的抑制作用最强(P<0.05);应用 0.2、0.5、1.0 mmol·L-1 AsA处理 25%PEG-6000 溶液干旱胁迫的种子,发现T3 组(施加 25%PEG-6000 和 1.00 mmol·L-1 AsA)种子的发芽率、发芽势和发芽指数与CK2组(仅施加 25%PEG-6000)相比,种子的发芽率、发芽势和发芽指数分别提高 53.33%(P<0.05)、40.00%(P<0.05)和 105.32%(P<0.01);利用 0.2、0.5、1.0 mmol·L-1 AsA处理 0.25 mol/L NaCl溶液盐胁迫的种子,发现T5 组(施加0.25 mol/L NaCl和1.00 mmol·L-1 AsA)种子的发芽率、发芽势和发芽指数与CK5 组(仅施加0.25 mol/L NaCl)相比,种子的发芽率、发芽势和发芽指数分别提高 40.00%(P<0.05)、34.45%(P<0.05)和27.51%(P<0.05).PEG-6000 和NaCl溶液模拟干旱和盐胁迫对唐古特种子萌发有显著的抑制作用,外源AsA能促进PEG-6000 和NaCl溶液模拟干旱和盐胁迫种子的萌发,起到良好的缓解干旱和盐胁迫作用,这为今后干旱和盐渍环境下唐古特大黄的引种驯化和人工栽培提供了重要技术支撑.
Abstract
To investigate the effects of PEG-6000 and NaCl on seed germination of Rheum tanguticum,as well as the alleviating effects of exogenous AsA on drought and salt stress,this study used PEG-6000 with mass fractions of 5%,10%,15%,20%,25%and 0.05,0.10,0.15,0.20,0.25 mol/L NaCl solution to simulate drought stress on R.tanguticum seeds,and screened out the PEG-6000 and NaCl concentration with the strongest inhibitory effect on seed germination.Subsequently,different concentrations of AsA were applied under this condition,and the germination rate,germination potential and germination index of the seeds were measured to reveal the effects of exogenous AsA on the germination of R.tanguticum seeds under simulated drought and salt stress.The results showed that as the concentration of the PEG-6000 and NaCl simulating drought and salt stress increased,the germination rate,germination potential and germination index of R.tanguticum seeds gradually decreased and the 25%PEG-6000 and 0.25 mol/L NaCl solution had the strongest inhibitory effect on seed germination(P<0.05).After treating the seeds under 25%PEG-6000 solution drought stress with 0.2,0.5 and 1.0 mmol·L-1 AsA,it was found that the germination rate,germination potential and germination index of the seeds treated with 25%PEG-6000 and 1.00 mmol·L-1 AsA were 53.33%(P<0.05),37.78%(P<0.05),and 88.82%(P<0.01)higher,respectively,compared to the control group(treated with 25%PEG-6000 only).After treating the seeds under 0.25 mol/L NaCl solution salt stress with 0.2,0.5 and 1.0 mmol·L-1 AsA,it was found that the germination rate,germination potential and germination index of the seeds treated with 0.25 mol/L NaCl and 1.00 mmol·L-1 AsA were 40.00%(P<0.05),34.45%(P<0.05),and 27.51%(P<0.01)higher,respectively,compared to the control group(treated with 0.25 mol/L NaCl only).This indicates that PEG-6000 and NaCl simulating drought and salt stress has a significant inhibitory effect on the germination of R.tanguticum seeds,and exogenous AsA can promote the germination of seeds under PEG-6000 and NaCl simulated drought and salt stress,playing a good role in alleviating drought and salt stress.This provides technical support for the introduction,domestication and artificial cultivation of R.tanguticum in drought and salt environments in the future.
NETL
NSTL
万方数据