水分胁迫对烤烟体内钾素累积的影响

以烤烟K326为材料,通过溶液培养条件下的厌氧处理及PEG渗透胁迫来模拟水分胁迫,研究了水分胁迫对烤烟体内钾素累积的影响。结果表明:在团棵期通过通氮气对烤烟进行厌氧处理6d时,烤烟各器官的钾含量及其累积量均显著降低,而根系向外溢泌钾的速度大幅度增加。旺长期内短时间低渗透胁迫强度刺激了烟株中K+的相对累积,胁迫时间延长或胁迫强度增加时,K+累积速率逐渐降低,甚至导致体内钾的损失。钾累积量的这种变化与渗透胁迫导致的根细胞膜结构的破坏及质膜选择透过性功能的降低有关。胁迫程度较高或时间较长时,细胞膜的相对透性增加,根中的K+大量外流。 

Effect of water stress on K content in flue-cured tobacco

Effect of anaerobic condition and osmotic stress on K content of flue-cured tobacco was studied with solution culture experiment. Results showed that the content and accumulation of potassium in different organs of flue-cured tobacco were decreased under anaerobic condition. Rapid efflux of K from hypoxia roots was attributed to increased membrane permeability to K, which was 1.63 times to that from normal plants roots. In grand growth period, low external osmotic potential caused by PEG-6000 solution stimulated K accumulation in leaves, stem and roots. High osmotic stress resulted in increased membrane permeability to K and rapid efflux of K from the roots. Loss of K increased as a function of time.