K^+对低温胁迫下紫椴叶片生理指标的影响

Effect of K^+ Concentration on Physiological Indexes of Tilia amurens under Low Temperature Stress

采用质量分数分别为50%、100%、150%、200%和250%的K+溶液处理2年生紫椴幼苗,在(-10±1)℃低温条件下分别处理2、4、6、8、10h,测定和分析其质膜相对透性、丙二醛(MDA)、可溶性糖及游离脯氨酸含量的变化,旨在探讨提高紫椴抗寒性的钾的最佳浓度范围。研究结果表明:不同质量分数的K+处理对紫椴幼苗叶片的MDA和游离脯氨酸的含量无规律性影响,但对相对电导率和可溶性糖含量产生了明显的调节作用,提高了紫椴幼苗对低温胁迫的抗性。可以认为,质量分数为250%的K+对紫椴抵抗低温胁迫的效果最佳。

2-year-old Tilia amurens seedlings were treated with different concentrations of kalium ion （50%, 100%, 150%, 200% , 250% ） aiming to approach the optimal concentration range for improving the cold resistance of seedlings. The changes of different physiological indexes of T. amurens seedlings, such as the relative osmosis of protoplasm membrane, contents of MAD, soluble sugar and dissociative proline, were detected under low temperature conditions （around - 10 degree C） after 2,4,6,8 and 10 hours of treatment, respectively. Results show that the contents of MDA and dissociative proline exhibit irregular changes, while the relative osmosis of protoplasm membrane and the content of soluble sugar present significant variations under different K^＋ treatments, which demonstrates that the resistance of T. amurens seedlings to low temperature stress is improved. The seedlings treated with K^＋ at a concentration of 250% have high cold-resistances.