中文摘要：

采用水培法研究了V（Ⅴ）、Cr（Ⅵ）单一及复合胁迫对小麦幼苗生长和生理特性的影响.结果表明,无论单一或复合胁迫,随着V、Cr浓度的增加,小麦幼苗鲜重、株高、叶绿素含量均呈先上升后下降的趋势.当V≤5 mg.L-1、Cr≤10 mg.L-1,小麦的鲜重、株高、叶绿素含量均高于对照,当V〉5 mg.L-1、Cr〉10 mg.L-1,则分别比对照降低0.2%—46.8%、0.8%—40.7%和2.5%—76.9%.丙二醛含量随着V、Cr胁迫浓度的增加而增大,与对照相比,含量增加了7.5%—251.6%.在V、Cr单一胁迫下,随着金属浓度增加细胞膜透性增大,比对照增加17.8%—59.8%,根系活力则下降8.1%—53.0%;复合胁迫时细胞膜透性先下降后上升,但始终高于对照,比对照增加了0.6%—126.2%;根系活力呈先升高后下降的趋势,降低6.1%—97.3%.研究表明在低浓度范围,复合胁迫在一定程度上可以缓解单一金属对小麦的毒害,对小麦幼苗生长具有拮抗作用;在高浓度范围两种金属复合胁迫对小麦幼苗的损伤和毒害作用比单一金属伤害更为严重,表现为协同作用.单一胁迫中Cr对小麦幼苗的毒性比V大.

英文摘要：

Effects of V,Cr single and combined stress on the growth and physiological characteristics of wheat seedling were studied by water culture.The results showed that with the increase of V,Cr concentrations,fresh weight,plant height and chlorophyll content of wheat seedling increased first and decreased afterwards.At low concentrations（V≤5 mg · L-1,Cr≤10 mg · L-1）,fresh weight,plant height and chlorophyll content were higher than those of the control,while at high concentrations（V〉5 mg · L-1,Cr〉10 mg · L-1）,they decreased by 0.2%—46.8%,0.8%—40.7% and 2.5%—76.9% respectively.The content of malondialdehyde（MDA） increased with increasing stress by 7.5%—251.6% respectively compared to the control.In V,Cr single treatment condition,the cell membrane permeability（CMP） increased and the activities of root subsystems decreased by 17.8%—59.8% and 8.1%—53.0% respectively with increasing stress,compared to the control.In V,Cr combined treatment condition,the cell membrane permeability decreased first and increased afterwards,and the activities of root subsystems increased first and decreased afterwards with increasing stress.The permeability increased by 0.6%—126.2% and the activities decreased by 6.1%—97.3%,compared to the control.The low concentration of V,Cr combined stress had antagonistic effect on the growth of wheat seedling,while,the high concentration of V,Cr had synergistic action.Toxicity and injury of V,Cr combined stress were higher than that of individual V,Cr treatment.The toxic harm of Cr stress was stronger than V stress.