Abstract: The relation between K⁺ influx and H⁺ efflux by roots of low-salt indica rice varieties cultured in 0.2 mmol/L CaSO₄ solution was studied. The linear correlations between K⁺ influx and H⁺ efflux in both 1.0mol/L KCl and 0.5mol/L K₂SO₄ media were highly significant The rates of K⁺ influxes by indica rice varieties were greater in KCl medium than those in K₂SO₄ medium, but rates of H⁺ effluxes were reverse. There was no corresponding relation between the rates of K⁺ influx or H⁺ efflux in both media. The above results indicated that the measurement of actdication of uptake medium (i. e. pH values decrease) could be used as a simple method for screening efficient K⁺ uptaking indica rice cultivars. but the uptake medium should be selectively used according to the field comditions.

Key words: indica rice, Roots: Potassium, Screening method, plant nutrition, uptake efficiency

摘要： 在0.2 mmol/L CaS04溶液中培养的不同籼稻品种低盐幼苗根系在1.0 mmol/L KCl和0.5 mmol/L K₂SO₄介质中的K+吸收和H+释放之间均呈非常显著的直线相关性。线性相关的斜率因测定方法而有所变化，但相关性意义不变。水稻在KCl介质的K^＋吸收速率比在K₂SO₄介质中的大， 但前者对应的H⁺释放速率却比后者的小，且K^＋吸收速率间没有对应的显著性相关意义。实验结果表明，虽然可以用直接测定吸收介质的酸化程度作为一种简捷的筛选高效K+吸收水稻品种的方法，但必须根据实际情况选用吸收介质。

关键词: 籼稻, 根系, 钾素, 筛选方法, 植物营养, 吸收效率