小麦不同品种吸收钾离子的动力学研究  

KINETICS OF K^+ ABSORPTION BY VARIOUS WHEAT VARIETIES

作　　者：黄建国[1] 杨邦俊[1] 袁玲[1] 

机构地区：[1]西南农业大学资源与环境学院,630716

出　　处：《植物营养与肥料学报》1995年第1期38-43,共6页Journal of Plant Nutrition and Fertilizers

摘　　要：小麦不同品种吸收钾离子(K^+)的动力学参数不同。米氏常数(Km)以绵阳11最大,红矮1最小;最大吸收速率(1max)繁6最高,红芒22最低。供试小麦各品种吸收K^+的补偿点(Cmin)≤3.44μ mol/L,远低于一般土壤溶液中的K^+浓度,说明土壤溶液中K^+浓度与小麦吸收K^+的需要相适应。此外,硝酸根(NO_3)、吲哚乙酸(IAA)和稀土显著促进小麦吸收K^+;但铵离子(NH_4^+)显著抑制K^+吸收;尿素对小麦吸收K^+无显著影响。动力学参数的测定表明,NH_4^+抑制K^+吸收的原因是提高了小麦吸收K^+的Km;而NO_3和稀土产生促进作用的原因分别是吸收K^+的Imax增加和Km减少。IAA能促进H^+分泌,导致小麦吸收K^+的速率提高。A solution culture experiment indicated that wheat varieties varied in kinetic parameters of K+ absorption. The smallest values of Michealis constant for K+ absorption (Km) was found with var. Hongai 1. and maximum rate of K uptake (Imax) was found with Hongmang 22. The greatest value of km for K+ absorption was obtained with Manyang 11 and the greatest value of Imax was observed with Fan 6. The compensa-, tion concentrations for K+ uptake (Cmin≤3.44μmol/L) by the tested wheat varieties were lower than K+ concentrations in soil solutions of commonly cultivated soils. This result showed that K+ contents in many soil solutions are adaptable to the requirement for K+ uptake by wheat. Moreover, NH4+ inhibited K+ uptake in contrast to NO3- , rare earth and indole acetic acid (IAA) which promoted K absorption. No obvious effect of urea on K+ uptake was observed. The reason for the inhibitation by NH4+ was that Km for K+ uptake was increased. The promotion by NO3- was accounted for by Imax increment. The enhancement of K+ uptake by rare earth can be explained by Km decrement. IAA Promoted H+ efflux which caused increasing in the rate of K+ uptake.

关 键 词：小麦 钾离子 吸收 动力学 品种 

分 类 号：S512.101[农业科学—作物学]