As Zn复合污染对小麦幼苗生长及生理生化反应的影响

Effects of As-Zn Combined Pollution on Growth and Physiological and Biochemical Reactions of Wheat Seedling

采用室内培养方法研究了As、Zn复合污染对小麦籽粒发芽及幼苗生理生化反应的影响。结果表明,低浓度Zn(≤100mg·L-1)对小麦生长起促进作用,但随处理浓度增大(300～500mg·L-1)对小麦的生长有明显的抑制作用,表现为发芽势、发芽率、芽长、芽重、根长、根重均减小,叶绿素含量降低,α-淀粉酶活力降低,MDA含量增大;低浓度A(s10mg·L-1)对小麦生长起抑制作用,As浓度越大抑制作用越明显。两者复合处理,As浓度≤20mg·L-1时,As、Zn表现一定的拮抗作用,Zn的加入能够缓解As对小麦幼苗的毒害,促进小麦幼苗的生长及叶绿素含量和α-淀粉酶活力的提高,使小麦幼苗根和芽中As含量下降;当As浓度>20mg·L-1时,二者表现一定的协同作用,加剧了单一污染对小麦幼苗造成的毒害。

The germination of wheat and physiological and biochemical reactions of seedling were studied with a series of experiments on combination of pollutants of As and Zn. The results showed that Zn played a positive effect on wheat grains in the presence of Zn≤100 mg·L^-1. With the increase of treatment concentration, it inhibited wheat growth including decreasing germination rate, germination potential, bud length and weight, root length and weight, weakening activity of or-amylase and increasing content of MDA. At the low level （10mg·L^-1）, As played a negative effect on plants. The higher treatment concentration was, the stronger its negative effects were. When wheat gains were polluted by As-Zn combination, Zn had an antagonism effect on As. When concentration of As was low （≤20 mg·L^-1）, the accession of Zn reduced the poison of As to wheat seedling, promoted growth of wheat seedling and increased content of chlorophyll and activity of α-amylase, decreased content of As in root and bud. In addition, Zn had a synergism effect on As when concentration of As was high （〉20 mg·L^-1）, which aggravated the poison of single pollution to wheat seedling. Otherwise, in any concentration of Zn the accession of As restrained Zn accumulation in root and bud of wheat seedling.