【摘要】 以苹果砧木———平邑甜茶 (MalushupenensisRehder)实生苗和 3年生盆栽富士苹果 /平邑甜茶幼树为试材 ,研究了根系Ca2 + 吸收动力学以及代谢抑制剂和温度对Ca2 + 吸收的影响。结果表明 ,在供钙浓度 0 0 2～ 0 5mmol/L范围内 ,苹果砧木根系钙离子吸收速率与钙浓度的关系符合米氏酶动力学模型 ,而在供钙浓度 0 5～ 5 0mmol/L范围内 ,钙吸收速率随供钙浓度的增加呈直线上升 ,并且连体根钙吸收速率的上升速度明显高于离体根。不论离体根还是连体根 ,钙吸收速率均受到代谢抑制剂 2 4 -二硝基酚的抑制 ,低供钙浓度 (0 2mmol/L)下受抑制的程度更高。低供钙浓度下 ,温度对平邑甜茶根系钙素吸收有明显影响 ,其中 15～ 2 0℃时α值和钙吸收速率最高。以根系表面积为单位计算的吸收根和延长根的钙吸收能力相近 ,而木质根α值为吸收根和延长根的 5 4%左右。更多还原

【Abstract】 The experiment were carried using apple seedlings (Malus hupenensis Rehder) and pot-cultured three-year old apple tree (Fuji/Malus hupenensis Rehder).It was studied that the kinetics of Ca 2+ uptake and the effect of temperature and metabolic inhibitor 24-Dinitrophend (24-DNP) on Ca 2+ uptake rate.The result show that the relation of Ca 2+ uptake rate and Ca 2+ concentration fits into Michaelis-Menten model under low concentration of Ca 2+( 0.02-0.5 mmol·L -1).The Ca 2+ uptake rate rise linearly with the increase of Ca 2+ concentration in both intact roots and excised roots and the rate of Ca 2+ uptake in intact roots exceeds in excised roots under high concentration of Ca 2+ (0.5-5.0 mmol·L -1).The rates of Ca 2+ uptake were inhibited by 24-DNP both in intact roots and excised roots.The inhibition rate was bigger under low concentration than high concentration and in excised roots than in intact roots.Under low concentration,the rate of Ca 2+ uptake was influenced markedly by temperature.The α value and Ca 2+ uptake rate in excised roots were the highest under 15-20 ℃.Under high concentration,the rate of Ca 2+ uptake did not affected markedly by temperature.The Ca 2+ uptake rate in absorbing roots was similar to extensive roots according to roots surface area.The α value in ligneous roots was 54% to absorbing roots and extensive roots.更多还原