外源甜菜碱对盐胁迫下龙胆幼苗生理特性的影响

Effects of Exogenous Betaine on Physiological Characteristics of Gentiana scabra Seedlings under Salt Stress

为了探究外源甜菜碱对盐胁迫下龙胆幼苗生理特性的影响,将龙胆幼苗进行盆栽试验,通过人工模拟盐胁迫条件,探讨在相同盐胁迫浓度下,施加不同浓度的甜菜碱对龙胆幼苗生长的影响。试验设置13.15mmol/L NaCl胁迫、蒸馏水为对照(CK),在相同浓度盐胁迫下,甜菜碱分别设置T1、T2、T3、T4(50、100、150、200 mmol/L)4个浓度梯度。处理1周后,测定幼苗的抗氧化物酶、脯氨酸、可溶性蛋白、MDA等生理指标。结果表明:处理后叶片中的抗氧化物酶(SOD、POD、CAT)活性均显著提高,在T3处理时,增幅最高分别达到56.3%、57.0%、167.0%;可溶性蛋白、叶绿素含量、净光合速率、脯氨酸等显著提升,增幅分别达到53.0%、64.0%、65.6%、99.9%;MDA含量减少,降幅为28.6%。综上所述,外源甜菜碱作为渗透调节物质,添加不同浓度处理,可以有效缓解盐胁迫下对龙胆幼苗的伤害,其中甜菜碱浓度为150 mmol/L处理时效果最佳。

In order to explore the influence of exogenous betaine on the physiological characteristics of Gentiana scabra seedlings under salt stress,the pot experiment of Gentiana seedlings was carried out.Through artificial simulation of salt stress conditions,the influence of different concentrations of betaine on the growth of Gentiana seedlings under the same salt stress concentration was discussed.In the experiment,13.15 mmol/L NaCl stress and distilled water were used as control(CK).Under the same concentration of salt stress,betaine gradients were set as T1,T2,T3 and T4(50,100,150 and 200 mmol/L).After one week of treatment,the physiological indexes of the seedlings,such as antioxidant enzyme,proline,soluble protein and MDA,were determined.The results showed that the activities of antioxidant enzymes(SOD,POD and CAT) in leaves were significantly increased,with the highest increase of 56.3%,57.0% and 167.0%,respectively.The soluble protein content,chlorophyll content,net photosynthetic rate and proline increased significantly by 53.0%,64.0%,65.6% and 99.9%,respectively.MDA content decreased by 28.6%.In conclusion,exogenous betaine,as an osmotic regulatory substance,can effectively alleviate the damage of Gentiana scabra seedlings under salt stress by adding different concentrations of treatment,and 150 mmol/L GB treatment has the best effect.