干旱胁迫下施钾水平与烟草叶片主要渗透调节物质的关系

Correlation between Potassium Application and the Main Osmotic Regulation Substances in Leaves of Tobacco under Drought Stress

采用砂培法对不同钾浓度处理下的烤烟NC89(Nicotiana tabacum L. cv. NC89)进行不同程度干旱胁迫,测定了株高、生物量等生长指标和主要渗透调节物质钾离子、可溶性糖、可溶性蛋白质及游离脯氨酸含量等生理指标,研究钾与其他渗透调节物质的关系。结果表明:轻度干旱胁迫下,高钾可使植株生长受胁迫程度得到缓解;重度干旱胁迫下,高钾则加重干旱胁迫对植株造成的损害;轻度干旱胁迫下随钾浓度升高烟草叶片钾含量有下降趋势,胁迫后期下降明显,而重度干旱胁迫下,高钾浓度能够增加烟草叶片钾含量;随着干旱胁迫时间推移可溶性糖含量先升高再降低,可溶性蛋白质含量持续上升,而游离脯氨酸含量先下降后上升。相关分析表明,干旱胁迫下钾与可溶性糖含量相关性不显著,与游离脯氨酸含量呈负相关性;而与可溶性蛋白质含量间呈极显著正相关。

Nicotiana tabacum L.cv.NC89 treated by different potassium concentration was cultured by sand under drought stress,determining the indicator of growth such as ： the plant height and the biomass and physiological indices including the main osmotic regulation substances ： the contents of potassium（K） and soluble sugar（SS） and soluble protein and free praline（PRO）.The resulted showed that the degree of stress suffered by plant was eased higher potassium concentration in mild drought stress,but the very reverse is the case in severe drought stress;the content of potassium was declined in W1 drought stress flowing the increase of potassium concentration,with a visible tendency in later period of stress,but,it was increased in W2 drought stress;the content of soluble sugar（SS） was upward then downward by on trend,and the content of protein（PRO） was increased continuously,and the content of free proline was in a t rend of decrease first and then increase flowing the process of time of drought stress.The result of correlation analysis was as follows： the content of potassium was insignificantly correlated with the content of soluble sugar under drought stress and significantly negatively correlated with the content of proline,but was remarkable positively correlated with the content of soluble protein.