Characteristics of Potassium-Enriched, Flue-Cured Tobacco Genotype in Potassium Absorption, Accumulation, and In-Ward Potassium Currents of Root Cortex

This study was to investigate the main traits of potassium-enriched, flue-cured tobacco genotypes related to potassium absorption, accumulation, and in-ward potassium currents of the root cortex. Hydroponic methods, K^＋-depletion methods, and patch-clamp, whole-cell recordings were conducted to study the accumulation of dry matter and potassium in different organs, and to measure potassium absorption and dynamic and in-ward potassium currents in potassium-enriched, fluecured tobacco genotypes. The average dry weights of leaves and whole plant of potassium-enriched, flue-cured tobacco genotype ND202 were 10.20, and 14.85 g, respectively, higher than JYH （8.50 and 13.11 g, respectively） and NC2326 （8.39 and 12.72 g, respectively）, when potassium concentration in the solution ranged from 0.1 to 50 mmol L^-1. Potassium accumulation in the leaves of ND202 was 18.6% higher than JYH and 34% higher than NC2326 when potassium concentration in the solution was superior to 0.5 mmol L^-1. The Vmax （the maximum velocity） of ND202 was 118.11 lamol FW g^-1 h^-1, obviously higher than that of JYH （58.87 μmol FW g^-1 h^-1） and NC2326 （64.40 μmol FW g^-1 h^-1）. In the in-ward potassium currents, the absolute value of current density （pA/pF） of ND202 was 60, higher than that of JYH （50） and NC2326 （40）. Potassium concentration in leaves, Vmax, and in-ward potassium currents, could be used to screen potassium-enriched, flue-cured tobacco genotypes.

Genotypic Variations in Potassium Absorption and Utilization by Amaranthus spp.

The kinetics of K+ absorption and the utilization of both applied K and K in a calcareous alluvisol with low available K by different genotypes of grain amaranth (Amaranthus spp.), an ancient pseudo-cereal that produces a large biomass and a rich source of healthy nutrients and mineral elements, were studied by means of ion depletion technique and pot experiments. Grain amaranth had a high affinity for K+ uptake in comparison with corn and cotton. However, there were differences among Amaranthus spp. in K absorption and utilization. Some cultivars such as R104, CX-4, Du001, Hy015 and Hr029 which had a higher rate of K absorption and stronger affinity for K+ were typical varieties with high K-use efficiency (KUE). The results showed that high KUE cultivars grew quickly, possessed stronger ability to take up soil slowly available K and mineral K, and did not respond to K fertilization in the soil with low available K. Correspondingly, grain amaranth cultivars CX-77, Cr024, Vd001, Re003 and Sn003 were relatively low in KUE. Compared with high KUE cultivars, they took up more soil available K and both of their dry matter accumulation and K uptake responded to K applied significantly.

Effects of Plant Growth Regulator on Absorption,Circulation and Contents of Potassium in Flue-cured Tobacco

[Objective] This study was to investigate the effects of plant growth regulator on accumulation and circulation of potassium in flue-cured tobacco.[Methods] Hydroponics experiment was adopted to study the effects of plant growth regulator（NAA,GA3,BR） on accumulation and circulation of potassium in flue-cured tobacco.[Results] The BR treatment increased the absorption of potassium,calcium and magnesium in flue-cured tobacco,reduced the potassium emission from the root,enhanced the accumulation and contents and promoted the circulation of potassium in the tobacco plants.There was no statistical difference between the NAA and GA3 treatment.And BR treatment was 0.52%,0.30%,0.28% higher than NAA treatment in enhancing potassium content in tobacco plants at 2,7,12 d after topping.In a word,the results showed that BR treatment was the most.[Conclusion] BR treatment could effectively enhance potassium content in tobacco plants after topping.

Potassium superoxide oxygen generation rate and carbon dioxide absorption rate in coal mine refuge chambers

The effects of the molding pressure of a KO2 oxygen plate and the initial concentration of CO2 on the oxygen generation rate, the oxygen generation efficiency, and the carbon dioxide absorption rate were studied using a YES-300 hydraulic press to alter the pressure when forming the oxygen plate used in a coal mine refuge chamber. In addition, changes in the initial concentration of CO2 used in the closed- box model were made by adjusting the CO2 supply system, and a CD-7 multi-function parameter instrument was employed to monitor and record the changes of O2 and CO2 concentration in the closed-box model. Results indicate that the oxygen generation rate of KO2 oxygen plates, the oxygen generation efficiency, and the carbon dioxide absorption rate decrease when there is an increase in the pressure used to mold the oxygen plates, but those values increase when the initial CO2 concentration increases. When the initial concentration of CO2 in the dosed-box model is 3.5% and the forming pressure is 10 kN, the average oxygen generation rate of 15 g KO2 oxygen plate is 11.88 ×10^-3 L/min, the oxygen generation efficiency is 80.3%, and the average CO2 absorption rate is 11.0 × 10^-3 L/min. Compared with the condition where the initial CO2 concentration is 1.5%, the results show that average oxygen genera- tion rate of oxygen plates increases by 88,9%, the oxygen generation efficiency increases by 88.9%, and the CO2 absorption rate increases by 100%.