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作 者 ：刘锋;黎明;李洪林;尹黎燕;李伟;

期 刊 ：武汉植物学研究 2009年 27卷 1期 页码：98-101

关键词：竹叶眼子菜；无菌培养系；NH4+-N；吸收动力学；

Keywords:Potamogetonmalaianus, Axenicseedlings, NH4+-N, Uptakekinetics,

摘 要 ：以竹叶眼子菜(Potamogeton malaianus)无菌系种苗为试验材料,研究了不同水体营养浓度水平(低营养:TN0.213 mg·L^-1,TP 0.0093 mg·L^-1;中营养:TN 0.71 mg·L^-1,TP 0.031 mg·L^-1;高营养:TN 7.1 mg·L^-1,TP0.31 mg·L^-1)对其生长与NH₄⁺-N的吸收动力学参数的影响。结果表明,不同浓度水体营养对竹叶眼子菜生长的影响较小,而NH₄⁺-N的吸收动力学参数有显著差异。竹叶眼子菜在高、中和低营养培养条件下的NH₄⁺-N最大吸收速率V_max分别为41.1、29.1、21.1μmol·g^-1·h^-1,米氏常数K_m分别为0.356、0.306、0.122 mmol·L^-1。竹叶眼子菜营养吸收动力学与其生长环境关系紧密,在低浓度生长环境中时,竹叶眼子菜可以通过降低K_m值来提高对营养离子的亲和力以满足营养需求;在高浓度生长环境中,该植物通过增大吸收潜力来适应高营养。

Abstract:The effects of the different nutrient conditions(low:TN 0.213 mg· L^-1,TP 0.0093 mg·L^-1;middle:TN 0.71 mg·L^-1,TP 0.031 mg·L^-1;high:TN 7.1 mg·L^-1,TP 0.31 mg·L^-1) on the growth and NH+4-N uptake kinetics of Potamogeton malaianus axenic seedlings were studied in hydroponic culture in the laboratory.It is showed that plant biomass was not significantly affected by different levels of nutrition after two months culture.The maximum absorb velocity of the plant(V_max) showed significant difference among different nutrient culture,ranging from 41.1 μmol·g^-1·h^-1(high nutrient condition) to 29.1 μmol·g^-1·h^-1(middle nutrient condition) and 21.1 μmol·g^-1·h^-1(low nutrient condition).The Michaelis constant(K_m) also showed significant difference among different nutrient culture,with values from 0.356(high nutrient condition) to 0.306(middle nutrient condition) and 0.122 mmol·L^-1(low nutrient condition).The results showed that NH₄⁺-N uptake kinetics of P.malaianus were closely related with its surrounding environment.This plant acclimates to low nutrient availability by increasing the affinity for nutrient uptake and conversely to high nutrient availability by increasing its uptake capacity.

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