外源硅对盐胁迫下黄芩幼苗生理生化特性的影响

摘要

以商洛盆栽黄芩幼苗为试验材料,在0.5% NaCl胁迫下,用不同浓度(0、0.01、0.025、0.05、0.10 g/L)外源硅(K2SiO3)处理8 d后,对黄芩幼苗叶片的SOD、POD、CAT活性及MDA和脯氨酸含量等指标进行测定,探讨外源硅对盐胁迫下黄芩幼苗生理生化特性的影响.结果表明,外源硅可以不同程度地提高黄芩叶片SOD、POD、CAT活性及MDA和脯氨酸含量,其中POD、CAT在Si2(0.05 g/L K2SiO3)处理下效果最佳,比盐对照组(CK2)分别高出120.0%、60.4%;SOD在Si1(0.025 g/L K2SiO3)处理下效果最佳,比CK2高出39.4%;MDA在盐胁迫下呈先升后降趋势,以Si2处理效果最佳,为对照组(CK1)的1.48倍;脯氨酸在Si1处理下效果最佳,达CK1的1.5倍.添加浓度为0.05、0.025 g/L的 K2SiO3可适度缓解盐胁迫对黄芩幼苗的伤害,增强黄芩的抗盐性.%In order to explore the effects of exogenous silicon on the physiological and biochemical characteristics of Shangluo Scutellaria baicalensis seedlings under salt stress,the author treated the potted seedlings of S. baicalensis with different concentra-tions(0,0.01,0.025,0.05,0.10 g/L)of exogenous silicon(K2SiO3)for 8 days under 0.5% NaCl stress, and then deter-mined the activities of SOD,POD and CAT,as well as the contents of MDA and proline in their leaves. The results indicated that exogenous silicon could inordinately increase the activities of SOD, POD and CAT as well as the contents of MDA and proline in the leaves of S. baicalensis seedlings. Under the treatment Si2(0.05 g/L K2SiO3), the activities of POD and CAT were the high-est, being 120.0% and 60.4% higher than those in the salt control(CK2), respectively. Under the treatment Si1(0.025 g/L K2SiO3), the activity of SOD was the highest,being 39.4% higher than that in CK2. Under the salt stress,the MDA content in-creased first and then decreased with the increase in exogenous silicon concentration,and it reached the peak in the treatment Si2, and this maximum value was 1.48 times that in the blank control(CK1). The proline content was the highest in the treatment Si1, being 1.5 times that in CK1. Adding 0.05 or 0.025 g/L K2SiO3could moderately remit the damage of salt stress to S. baicalensis seedlings, and strengthen their salt resistance.