为探讨大豆对镉(Cd)胁迫的生理反应及忍耐机理,以8157为供试材料,采用Hoagland营养液培养和土壤盆栽培养试验,研究了添加不同浓度外源Cd对大豆的生理效应及Cd吸收分布的影响。结果表明,大豆吸收的Cd向地上部转运的比率较高,根系对Cd的阻滞作用较弱;植株体内的Cd主要以NaCl提取形态存在(占89.61%),降低了Cd的生物毒害性。土壤添加低浓度Cd(0.25~0.50mg·kg-1),大豆籽粒中Cd-P表现为协同作用,Cd浓度升高则转为拮抗作用;不同浓度Cd处理,籽粒中Cd-Zn表现为协同作用,叶片中Cd-Zn则表现为拮抗作用。Cd胁迫促进大豆体内脯氨酸(PRO)的合成,提高了过氧化物酶(POD)的活性,增强了大豆对Cd胁迫的防御和抵抗能力。
To explore the physiological response and tolerance mechanism of soybean(Glycine max) under cadmium stress,hoagland culture solution and pot experiment were conducted as a case of 8157 variety,both physiological response and distribution of Cd of soybean plant tissues were studied under different Cd concentrations.Results showed that Cd ratios of shoot was higher,while root obstruction effective of Cd was poorer.NaCl extractive Cd form was the mainly(account for 89.61%) in soybean plants tissues,so the Cd biotoxicity was declined.synergistic effect of Cd-P in soybean seeds was found under low Cd concentrations(0.25~0.50 mg·kg-1),but antagonistic effect was revealed with Cd concentration increasing.The synergistic effect of Cd-Zn in soybean seeds was main,and its antagonistic effect in leaf was found under experimental Cd concentrations.Proline(PRO) biosynthesis was promoted while peroxidase(POD) activities was accelerated and resistivity of soybean plant to Cd stress was enhanced.