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作 者 ：周卫;林葆

期 刊 ：植物营养与肥料学报 1996年 2卷 3期 页码：226-232

关键词：花生根系；钙；吸收特性；

摘 要 ：运用电子探针、⁴⁵Ca示踪及水培方法研究花生根系钙素吸收特性,结果表明花生根伸长区与成熟区均可吸钙,二者吸钙量分别占吸钙总量的28.9％～34.7％和71.1％～65.3％。在供钙浓度为0～0.5nmol/L范围,根系钙素吸收符合Michaelis-Menten酶动力学模型。此时其完全受代谢控制,完整根Km值为0.0549mmol/L、Fmax为3.81nmol/(cm·h);断离根Km为0.0534mmol/L、Fmax为3.79nmol/(cm.h)。此后随供钙浓度增加,其受非代谢因素影响越大。供钙浓度为2.0mmol/L时,代谢因素对吸钙总量的贡献为63.2％,而非代谢因素的贡献为36.8％。

Abstract:The characteristics of calcium absorption by peanut roots was inverstigated by using ⁴⁵Ca trace technology, electron X-ray microanalysis and solution culture. It was found that calcium can be absorbed in either elongation zone or mature zone of peanut roots, of the total Ca uptake. 28.9% ~ 37.4% was attributed to elongation zone, and other (71.1%~65.3%) to mature zone. When solution Ca concentration ranged from 0~0.5 mmol/L, Ca uptake could completely mediated by metabolism, and the relationship between Ca²⁺ absorption rate and its concentration could be described by Michaelis-Menten dynamics model, where Km was 0. 0549mmol/L and Fmax was 3.81nmol/(cm.h) Nonmetabollc effect of Ca absorption appeared or increased with the increase of Ca²⁺ concentration. When solution Ca concentration was 2.0mmol/L, 63. 2% of Ca uptake was metabolically mediated, and 36. 8% was mediated by nonmetabolic factors.

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