锌镉单一胁迫荠菜和地肤子的生长特性及对重金属的积累特征

The Growth Characteristics and Accumulation Abilities of Heavy Metals of Brassica juncea and Kochia Scoparia Under Zn and Cd Stress

以荠菜和地肤子为供试植物,通过水培实验,研究荠菜和地肤子在Zn、Cd单一胁迫下的生长特征、生化指标以及对锌镉吸收积累的规律。结果表明:Zn、Cd对荠菜和地肤子种子萌发、芽和根的伸长均产生抑制作用;在Zn、Cd单一胁迫下,随着处理浓度的升高,荠菜和地肤子体内游离脯氨酸含量均呈现先升后降趋势,地肤子体内过氧化物酶活性呈现一定的上升态势;从总量上来看,随着Zn、Cd单一处理浓度的增加,荠菜和地肤子体内各部分的累积量也相应增加。Zn胁迫下,荠菜的Zn积累量呈现为地上部分>根系。在Cd胁迫下,低浓度Cd^(2+)小于5 mg/L时,荠菜和地肤子均表现为根系>地上部分;高浓度Cd^(2+)大于15 mg/L时,则表现为地上部分>根系。综合实验结果,可初步判断荠菜和地肤子能积累和忍受一定量的Zn、Cd,荠菜和地肤子根茎发达,生长过程中通过根系带走部分重金属Zn、Cd,因此荠菜和地肤子具有修复重金属Zn和Cd污染土壤的潜能。

Using Brassica juncea and Kochia Scoparia as experimental plant,through the hydroponic experiments,the growth characteristics,biochemical index and accumulation abilities of heavy metals of B.juncea and K.Scoparia under Zn,Cd stress were studied.The results showed that Zn and Cd inhibited the germination,bud and root elongation of B.juncea and K.Scoparia;Under the stress of single zinc(Zn)and single cadmium(Cd),with the increase of treatment concentration,the free proline in B.juncea and K.Scoparia increased firstly then reduced,the peroxidase in K.Scoparia increased;In terms of the total amount,with the increase of treatment concentration,the accumulation of various parts of B.juncea and K.Scoparia were also increased correspondingly.Under Zn stress,the accumulation of Zn in the aerial parts of B.juncea was higher than that of roots.Under Cd stress,when the low concentration of Cd^2+was less than 5 mg/L,the roots of B.juncea and K.Scoparia were higher than the aerial parts.When the high concentration of Cd^2+was greater than 15 mg/L,the aerial parts were higher than the roots.The results of the present study suggested that B.juncea and K.Scoparia were able to accumulate and tolerate in a certain amount of Zn and Cd.In a conclusion,the B.juncea and K.Scoparia have a promising remedial potential for Zn and Cd contamination soil,because they have the well developed rhizome which have the absorbing and accumulation function for Zn and Cd from the contaminated soil.