硒对铬胁迫下蔬菜幼苗生长的影响

Effects of Se on the Growth of Vegetable Seedlings Under Cr Stress

采用室内培养皿水培方法,考察了Cr3+、Cr6+、Se4+、Se6+对油菜、白菜、萝卜种子发芽与幼苗生长的影响和不同价态硒对铬的拮抗作用。结果表明,不同价态的Cr和Se在低浓度时均能促进植物种子萌发,提高发芽势和发芽率,促进苗与幼根的生长,而高浓度时不利于植物种子萌发和生长。种子根生长的抑制指数与铬浓度的对数呈显著的正相关性。Cr3+对不同蔬菜种子的半数效应量(EC50)为白菜>油菜>萝卜,Cr6+对种子的EC50为萝卜>油菜>白菜;蔬菜种子萌芽和根生长对Se的耐受性为萝卜>白菜>油菜。高价Cr和Se的生理毒性大于低价的Cr和Se。低浓度的Se对不同价态Cr胁迫下蔬菜幼苗生长具有拮抗作用,而高浓度的Se对不同价态Cr胁迫下蔬菜幼苗生长具有协同效应。

Using rape, cabbage and radish seeds as the experimental materials, the effects of selenium or chromium on the growth of vegetable seedlings and effects of selenium on the growth of vegetable seedlings under chromium stress were investigated by water culture. The results showed that various valence chromium and selenium at low concentration could improve germination force, germination rate, germination index, vigor index and inhibition index of vegetable root growth, but at high concentration had inhibition effect on the germination and growth of seeds. There was a significantly positive correlation between the logarithm of chromium and selenium concentration and the inhibition index of the seedling root growth. The resistance of germinating seed against Cr and Se varied with the vegetables. ECso （mg·L^-1） of Cr^3＋ was 24.01 for rape, 28.25 for cabbage and 23.93 for radish, and ECso （mg·L^-1） of Cr^6＋ was 5.16 for rape, 4.14 for cabbage and 9.32 for radish. EC50 （mg·L^-1） of Se^4＋ was 0.89 for rape, 1.89 for cabbage and 6.63 for radish, and ECso （mg· L^-1） of Se^6＋ was 0.47 for rape, 1.44 for cabbage and 4.76 for radish. The inhibition effect of Cr on seed germination and the growth of seedlings was stronger than that of Se, and the inhibition effect of Cr^6＋ and Se^6＋ was stronger than that of Cr^3＋ and Se^4＋ respectively. Low concentration of selenium had antagonistic effect on the growth of vegetable seedlings under chromium stress, while, the selenium at high concentration had synergistic action.