重金属胁迫下小豆种子萌发特性及幼苗期富集效应

Germination Characteristics and Accumulation Effects of Adzuki Bean under Heavy Metal Stress

为探究重金属(Cu^2+、Zn^2+、Cr^6+)胁迫下小豆种子萌发特性和幼苗对重金属离子的富集效应,以“晋小豆6号”为材料,设置不同浓度(5、10、50、100、200、300、400mg/L)重金属(Cu^2+、Zn^2+、Cr^6+)梯度,测定小豆种子的发芽指标变化及幼苗根、茎、叶中各种重金属的积累量。结果表明:当Cu^2+浓度为5、300、400mg/L时,小豆种子发芽势高于对照,而在相同浓度的Cr^6+、Zn^2+胁迫下小豆种子发芽势低于对照。3种重金属不同浓度对小豆发芽率整体影响趋势相近,在重金属浓度为50mg/L时小豆幼苗根长最长;当Cu^2+浓度为200~400mg/L时小豆下胚轴长明显短于对照,Zn^2+和Cr^6+浓度为5~400mg/L时,随Zn^2+、Cr^6+浓度升高小豆下胚轴生长呈先升后降的趋势,且都在浓度为100mg/L时下胚轴最长。小豆幼苗对重金属Cu^2+的累积量较高,对Zn^2+的累积量次之,对Cr^6+的累积量最低,且主要集中在根部,只有少量富集在茎和叶片中。适宜重金属浓度对小豆种子萌发具有促进作用,其根部对重金属有良好吸收,种植小豆对改善土壤环境有极大帮助。

In order to investigate the germination characteristics of adzuki bean seeds under heavy metal stress(Cu^2+,Zn^2+,Cr^6+)and the accumulation in seedlings,the germination index of adzuki bean seeds was studied under different concentrations of heavy metal stress(5,10,50,100,200,300,400mg/L)based the material of"Jinxiaodou No.6".And the accumulation of different heavy metals in the roots,stems and leaves of the bean seedlings was measured.The results showed that:when Cu^2+stress concentration was 5,300 or 400mg/L,the germination potential of adzuki bean was higher than that of the control,which was opposite to that of under the same concentration of Zn^2+and Cr^6+stresses.The three heavy metals had the similar effects on germination rate of adzuki bean at different concentrations.While the stress concentration was 50mg/L,the root length of adzuki bean seedlings was significantly longer than that of the control.While Cu^2+concentration was 200-400mg/L,it was observed that the hypocotyl length was shorter than that of the control.As the concentration was 5-400mg/L of Zn^2+and Cr^6+,the growing of hypocotyls of adzuki bean was risen first and then fallen,and the hypocotyl was the longest at the concentration of lOOmg/L.The accumulation of heavy metal Cu^2+was higher in adzuki bean seedlings,followed by Cr^6+and Zn^2+,which mainly enriched in the roots,and partly in the stems and leaves.The suitable concentration of heavy metals can promote the germination of adzuki bean seeds,and the roots can absorb heavy metals well.Planting adzuki beans can make the soil environment better.