棉花钾吸收动力学的初步研究和应用

研究了影响棉花钾吸收动力学参数的因素,初步确定了钾吸收动力学方法在棉花上应用的条件,比较了转基因抗虫棉新棉99B和常规棉中棉所35苗期的钾吸收特性。结果表明,棉花钾吸收动力学参数受到苗龄、耗竭液中起始钾浓度及培养液中钾浓度的显著影响,在苗龄较小(3～4叶苗与4～5叶苗相比)、耗竭液中起始钾浓度较高(0.35与0.2mmol·L1相比)、培养液中钾浓度较高(2.0与0.5mmol·L1相比)的情况下,Km、Cmin均比较高,而Imax在前两种条件下较高、在后一种条件下较低。在5～6叶期,新棉99B的Imax显著降低于中棉所35,而Km、Cmin显著高于后者(培养液中K 为0.5mmol·L1),耗竭液中起始K 为0.2mmol·L1),说明新棉99B吸收有限钾的能力低于中棉所35。

Preliminary Study of K+ Uptake Kinetics of Cotton (Gossypium hirsutum L.)and its Application

It has been a main problem in cotton production that transgenic insect-resistant cotton is prone to premature senescence induced by K+ deficiency, which makes it necessary to study K+ up take characteristics and, on the basis of it, to screen cotton cultivars with high K+ uptake efficiency. This experiment studied the factors influencing K+ uptake kinetic parameters of cotton, preliminarily identified the conditions of K+ uptake kinetic applied to cotton, and compared the K+ uptake characteristics of transgenic insect-resistant cotton cultivar, DP99B, and conventional cotton cultivar, CCRI 35, at seedling stage. The results showed that K+ uptake kinetic parameters were significantly affected by seedling stage, initial K+ concentration in depleting solution and K+ concentration in culturing solution. Higher Km and Cmin resulted from younger seedling (3～4 vs. 4～5 leaf stage), higher initial tions, and lower Imax came into being under the last situation. Compared with CCRI 35, DP99B had uptake limited K+ was weaker than that of CCRI 35.