水磷互作对不同磷效率基因型大豆苗期生理生化指标的影响

THE COUPLE EFFECT OF WATER AND PHOSPHORUS ON PHYSIO-BIOCHEMICAL CHARACTERS OF DIFFERENT GENOTYPIC SOYBEAN AT SEEDLING STAGE

以不同磷效率基因型大豆黑河27、黑河29为试验材料,通过盆栽试验,在控制水磷的条件下,研究了不同磷效率基因型大豆的细胞膜透性、丙二醛积累、保护酶活性(SOD、POD)、水分状况以及根系活力等差异。结果表明,在磷和水分供应充足的情况下,2个基因型大豆生理活性表现极强。低磷和干旱胁迫下,黑河27以较高的根系活力、SOD和POD酶的生理活性,大幅度降低细胞膜透性来抑制和减少低磷和干旱胁迫所造成的不利影响,从而提高磷素营养和水分利用效率,而黑河29主要通过增加根系面积等形态变化来适应低磷和干旱胁迫,这就决定其适应在供磷充分条件下生长。磷高效基因型改善了大豆体内水分状况,提高了大豆的耐旱能力。

Soybean cultivars with high phosphorus efficiency adapt to P stress environment easily. Previous studies have focused on the mechanism of soybean＇s adaptation to low P stress. But the coupling effect of water and phosphorus on different P efficiency genotypic soybean is less documented. Therefore,pot experiments were conducted in 2006 year, with P high efficient soybean Heihe 27 and P low efficient soybean Heihe 29 as materials, to determine the influence of water and P coupling on physio-biochemical characters of different genotypic soybean at seedling stage. Two P （applied P and without P） and four water （100%,70%,50% and 30% of the maxi- mum field water holding capability） treatments were designed and endosmosis permeability, root active absorbing area, malondiaidehyde （MDA） content, relative conductivity% Superoxide dismutase （SOD）,peroxide （POD）enzyme activity and leaf water content were determined. Physiological activities were greatly enhanced due to sufficient P and water supply for both eultivars; under P and water stress, Heihe 27 could resist the low phosphorus and drought stress by improving root vigor, SOD and POD activity, reducing endosmosis permeability. While Heihe 29 only had some morphological changes sueh as increasing root area to adapt to low P and drought stress,which showed it could grow well under sufficient P condition. The result also suggest P high efficient soybean have better drought tolerance by ameliorating water supply status under drought stress.