不同番茄品种镁吸收特性比较

【目的】 通过研究不同番茄品种对镁吸收的差异，为缺镁地区番茄镁高效品种筛选提供理论依据。 【方法】 以北方日光温室主栽的3个番茄品种中杂9号、改良毛粉、金棚朝冠为研究对象，将培育苗分别于15℃和30℃下，在镁浓度为0、0.6、1.2、1.8、2.4、3.0 mmol/L的营养液中吸收 24 h，通过养分吸收动力学方法确定吸收参数来比较不同番茄品种间的差异。同时将相同的3个番茄品种在不加镁 (0 mmol/L) 和中等镁 (1 mmol/L) 浓度条件下水培45 d，比较镁吸收量、镁流入速率及番茄对镁吸收利用的差异。 【结果】 养分动力学试验结果表明，15℃时番茄对镁的吸收速率高于30℃，两个温度条件下，3个番茄品种对镁的吸收速率均表现为改良毛粉 > 金棚朝冠 > 中杂9号。3个品种最大吸收速率 (I _max) 和亲和力系数 (K_m) 均有显著差异，I_max和K_m值均为改良毛粉 > 金棚朝冠 > 中杂9号。培养45 d的结果表明，在缺镁和中等镁浓度条件下，3个番茄品种镁吸收量、镁流入速率均有显著差异，其中改良毛粉镁吸收量显著低于金棚朝冠和中杂9号，金棚朝冠和中杂9号间差异未达显著水平。 【结论】 温度影响番茄对镁的吸收，但并未改变品种间的差异。低镁条件下，金棚朝冠和中杂9号对镁具有较大吸收潜力，改良毛粉的吸收潜力显著低于前两者。

Comparison of magnesium uptake properties of three tomato cultivars

【Objectives】 The aim of this study was to investigate the difference in magnesium (Mg) uptake among different tomato cultivars, and to provide a scientific basis for selection of tomato cultivars with high uptake efficiency. 【Methods】 Two hydroponic experiments were conducted using three widely planted tomato cultivars (‘Zhongza No.9’, ‘Gailiangmaofen’ and ‘Jinpengchaoguan’) in North China. A 24 h uptake kinetics experiment (Mg levels: 0, 0.6, 1.2, 1.8, 2.4, 3.0 mmol/L) at two different temperatures (15℃ and 30℃) was conducted to evaluate Mg uptake kinetics. A 45 days’ hydroponic experiment (two Mg levels: 0, 1.0 mmol/L) was conducted to compare Mg uptake and utilization efficiency. 【Results】 The uptake kinetics results showed that Mg uptake rate at 15℃ was higher than that at 30℃. The Mg uptake rate of three tomato cultivars at two temperatures was ‘Gailiangmaofen’ > ‘Jinpengchaoguan’ > ‘Zhongza No.9’. There were significant differences in the maximum uptake rate (I _max) and the affinity coefficient (K_m) among the three tomato cultivars, and the two parameters of the three tomato cultivars was ‘Gailiangmaofen’ > ‘Jinpengchaoguan’ > ‘Zhongza No.9’. The Mg uptakes among three tomato cultivars in the 45 day experiment were significantly different in the two Mg levels. Mg uptake of ‘Jinpengchaoguan’ was significantly lower than those of ‘Jinpengchaoguan’ and ‘Zhongza No.9’, and there was no significant difference between ‘Jinpengchaoguan’ and ‘Zhongza No.9’. 【Conclusions】 Growth temperature affects the uptake rate of Mg, but does not change the uptake characteristics of different cultivars. ‘Zhongza No.9’ and ‘Jinpengchaoguan’ show a high Mg uptake potential at low Mg supply level, while ‘Gailiangmaofen’ does not.