重金属铅锌镉对紫茎泽兰种子萌发及幼苗根长的影响

Effects of Lead,Zinc and Cadmium Stresses on Seed Germination and Seedling Root Growth of Eupatorium adenophorum

试验以紫茎泽兰(Eupatorium coelestinum L.)种子为材料,研究了重金属铅(Pb)、锌(Zn)、镉(Cd)单一及复合胁迫对种子萌发及幼苗根长的影响。结果表明,当Pb浓度在100～4 000μmol/L时,紫茎泽兰种子的发芽率、发芽指数和发芽势都随着Pb浓度的增加而降低,但是当Pb浓度为100～200μmol/L时,其发芽率、发芽指数及发芽势都比对照高,其中在100μmol/L处理下其发芽率、发芽指数及发芽势都是最高的,分别为94.67%、42.25和89.67%;在Zn浓度为100～4 000μmol/L范围内,紫茎泽兰种子的发芽率、发芽指数和发芽势随着Zn浓度的增加而降低;在Cd浓度为20～1 000μmol/L范围内,紫茎泽兰种子的发芽率、发芽指数和发芽势都随着Cd浓度的增加而降低;在低浓度Pb(100μmol/L)+Zn(100μmol/L)复合胁迫下,其发芽率是最高的,为94.67%,之后随着复合浓度的增加,其发芽率、发芽指数和发芽势呈下降趋势;紫茎泽兰种子的发芽率、发芽指数和发芽势随着复合重金属Pb+Cd、Zn+Cd、Pb+Zn+Cd浓度的增加而降低。无论是在单一还是复合重金属处理下,紫茎泽兰的幼苗根长与对照相比明显受到抑制。

Using Eupatorium adenophorum as material, effects of single or combinative stress of Pb, Zn and Cd on seed germination and seedling root growth of E. adenophorum were investigated. The result showed that germination rate, ger- mination index and germination energy of E. adenophorum seeds decreased as the Pb treated concentration increasing with the extent of 100- 4 000μmol/L. Germination rate, germination index and germination energy were higher than that of control when Pb concentration was within the extent of 100 - 200 μmol./L, and the highest germination rate, germination index and germination energy was 94.67% ,42.25 and 89.67% respectively at 100μmol/L of Pb treated. Germination rate,germination index and germination energy of E. adenophorum seeds decreased as the Zn concentration increasing, within the extent of 100-4 000μmol/L. The germination rate, germination index and germination energy of E. adeno- phorum decreased as the Cd concentration increasing, within the extent of 20-1 000μmol/L. Under lower combinative stresses with Pb（ 100μmol/L） ＋ Zn （100μmol/L）, the germination rate of E. adenophorum seeds was highest and reached to 94.67% ,but germination rate, germination index and germination energy showed downward trend as Pb ＋ Zncombined treatment concentration increased. Germina- tion rate, germination index and germination energy of E. adenophorum seeds decreased as Pb ＋ Cd, Zn ＋ Cd, Pb ＋ Zn ＋ Cd concentration increasing . Despite of single or combinative treatment with heavy metals, the seedling root length of E. adenophorum was inhibited significantly than that of control.