渗透胁迫对不同供钾水平烤烟叶片抗旱生理指标的影响

采用水培试验研究了渗透胁迫对不同钾素营养水平下烤烟叶片脯氨酸,可溶性糖和丙二醛含量的影响。结果表明,渗透胁迫下各供钾水平处理烟叶中脯氨酸,可溶性糖和丙二醛含量均显著增加,胁迫处理24h达到高峰,之后含量下降。不同胁迫强度上述指标的变化趋势基本一致,但渗透势-0.2Mpa处理烟叶脯氨酸和丙二醛含量的峰值显著高于渗透势-0.4Mpa处理。渗透胁迫下提高供钾水平可以促进烤烟叶片脯氨酸和可溶性糖积累,降低丙二醛含量,增强烟株的抗旱性。

Effect of Osmotic Stress on Physiological Indices of Drought Resistance of Flue-cured Tobacco Leaves under Different Potassium Supplying

A water-culture experiment was employed to study the effect of osmotic stress on contents of proline (PRO), soluble sugar (SS) and malondaldehyde (MDA) in flue-cured tobacco leaves under different potassium supplying. The results showed that the contents of PRO, SS and MDA in the leaves of different potassium supplying treatment increased significantly under osmotic stress, and the peak value appeared at 24h and then declined. The changes of these indices were almost the same between the two osmotic stress treatments, but the peak value was obviously higher at the osmotic potential of -0.2MPa than that of -0.4MPa. Under osmotic stress, significant accumulation of PRO and SS in tobacco leaves was observed and the notable decrease of MDA content was also found with the increasing of potassium supply, which suggested that the drought resistance of tobacco plant was improved.