不同钾效率烟草品种钾素吸收特性及动力学特征分析

Potassium absorption and kinetics by different tobacco varieties at different potassium efficiency

为探讨不同钾效率烟草品种对钾素吸收利用的差异,通过砂培盆栽试验研究了10个烟草品种的钾素营养特性,对其生物量、钾含量(质量分数)、钾积累量、根系生理指标以及钾离子吸收动力学特征进行分析,并对钾效率进行评价和分类。结果表明,10个烟草品种的钾素吸收效率和利用效率总体上呈负相关,可划分为3种类型。高效吸收低效利用型烟草具有较高的钾含量,低效吸收高效利用型烟草钾含量较低。根系钾离子吸收动力学参数显示,高效吸收低效利用型烟草的最大吸收速率(V_(max))和综合吸收能力(α)分别较低效吸收低效利用型升高90.6%和215.6%,较低效吸收高效利用型升高36.1%和90.6%。低效吸收高效利用型烟草的V_(max)和α较低效吸收低效利用型分别升高40.0%和65.6%,而米氏常数(K_m)下降8.6%。低效吸收高效利用型烟草的最低吸收浓度(C_(min))和耐瘠能力(β)分别较高效吸收低效利用型下降15.7%和10.2%,较低效吸收低效利用型下降15.9%和13.1%。根系生理指标显示,高效吸收低效利用型烟草具有更高的根系活力、可溶性蛋白含量和钾离子内流速率。

To explore different potassium absorption and utilization between tobacco varieties with different potassium efficiency, a sand-culture pot experiment was carried out to study the potassium nutrition characteristics from 10 tobacco varieties. The biomass, potassium content(mass fraction), potassium accumulation, root physiological indicators and potassium uptake kinetic characteristics from the 10 tobacco varieties were detected, and their potassium efficiency was evaluated and classified. The results showed that the potassium absorption efficiency of 10 tobacco varieties negatively correlated to their utilization efficiency, and the tobacco varieties could be divided into 3 types: varieties with high absorption efficiency and low utilization efficiency(Type 1), varieties with low absorption efficiency and low utilization efficiency(Type 2) and varieties with low absorption efficiency and high utilization efficiency(Type 3). Type 1 tobacco had higher potassium contents, and Type 3 tobacco was contrary. The potassium uptake kinetic parameters indicated that comparing with Type 2 and Type 3 tobaccos, the maximum uptake rate(Vmax) and comprehensive absorption capacity(α) of Type 1 tobacco increased by 90.6%, 215.6% and 36.1%, 90.6%, respectively. Comparing with Type 2 tobacco,the Vmaxand α of Type 3 tobacco increased by 40.0% and 65.6%, respectively. However, the Michaelis-Menten constant(Km) of Type 3 tobacco decreased by 8.6%. Comparing with Type 1 and Type 2 tobaccos, the minimum equilibrium concentration(Cmin) and tolerance to infertility( β) of Type 3 tobacco decreased by 15.7%, 10.2%and 15.9%, 13.1%, respectively. Root physiological indicators suggested that Type 1 tobacco had higher root vigor, soluble protein contents and K^+ influxes.