红壤中La对油菜的剂量效应和临界浓度

通过盆栽试验,研究了红壤中不同浓度La对油菜的生长、产量、叶绿素含量和过氧化物酶活性的影响.结果表明:低浓度La可促进油菜生长并增加产量,但达不到显著水平;300mg·kg^-1以上的高浓度La则显著抑制油菜生长和降低产量.La浓度为600mg·kg^-1时油菜死亡,油菜产量降低一半时的EC50=300mg·kg^-1.La浓度为15 mg·kg^-1时油菜叶片叶绿素和叶绿素a/b分别减少,POD活性随La的浓度的增加和施加时间的延长而逐渐增加.

Does Response of Rape to La and Critical Concentration of La in Red Earth

The effects of different concentration of La added in red soil on the growth, yield, content of chlorophyll and peroxidase(POD) activity of rape were studied by pot experiments The results showed that the growth and yield of rape could be improved by low concentration of La³⁺, however there was no significant difference between the treatment and the control, and inhibited when the dose were more than 300mg·kg^-1 and killed after 600mg·kg^-1 La was added The decrease of chlorophyll content and chlorophyll a/b was observed when the exogenous concentration of La was more than 15mg·kg^-1 POD activity increased gradually with increasing concentration and prolonging reaction The feasible application level of La was suggested to be below 15mg·kg^-1.