稀土元素在甘蔗(Saccharum officinarum L.)体内运转、分配及其对磷、钾素吸收的影响

应用放射性同位素~(141)Ce、~(32)P及~(86)Rb研究了甘蔗(Saccharum officinarum L.)对稀土元素饰的吸收及其对磷、钾素(以~(86)Rb代K)吸收的影响。结果表明,甘蔗可以通过其根系或叶片吸收稀土元素铈。甘蔗对铈的吸收,在处理后第1—7天,随着时间增加而增加。处理后第7天吸收达到高峰(最大值),约为第1天吸收的2—3倍,以后缓慢下降。甘蔗植株对铈的吸收利用率仅为0.836—3.240％。铈在甘蔗各器官中的分配,喂饲根部处理表现为:根>茎>叶;涂布叶片处理表现为:叶>茎>根。300、500、800ppm的R(NO_3)_3·4H_2、Ce、La、Sm、Pr、Nd和Y的硝酸化物处理,均能提高甘蔗根系对磷(~(32)P)、铷(~(86)Rb)的吸收;而1000ppm的各种稀土元素处理则表现较明显的抑制作用。200ppm的R(NO_3)_3·4H_2·O、Ce、La、Sm、Pr、Nd及Y的硝酸化物处理能显著地提高甘蔗根系的活力,比对照提高22.33—44.54％。其中尤以Ce、La的硝酸化物及R(NO_3)_3·4H_2O为最显著。

STUDIES ON THE ABSORPTION, DISTRIBUTION OF RARE EARTH ELEMENTS AND ITS EFFECT ON ABSORPTION OF PHOSPHORUS AND POTASSIUM IN SUGARCANE (Saccharum officnarum L.)

Study on the absorption,distribution and translocation of rare earth elements (RE) and their effets on absorption of phosphorus and potassium (86Rb as tracer) in sugarcane (Saccharum officinarum L.) showed that the sugarcane could absorb soluble RE fast by its root or leaves.Within the 1-7 days after treatment,the absorption rate of cerium (141Ce) in organs of the plant increased with the time.At the 7th day after treatment,the absorption rate of 141Ce by sugarcane plant reached the maximum which was about 2-3 times of that at the 1st day and after that it gradually decreased.The utilization efficiency of cerium (141Ce) by sugarcane plant was 0.836-3.24%.The absorption and distribution of RE in sugarcane plant varied with the treatment methods.It was shown that about 90% 141Ce in nutrient solution was concentrated in the roots while only about 10% of them was transfered into the shoots.The distribution and accumulation of 141Ce in sugarcane plant was in order of root>stem>leaf.If smeared on the leaf of sugarcane,the distribution and accumulation of 141Ce in sugarcane plant was in order of leaf>stem>root.When treated with 300,500 and 800ppm R ( NO3)3·4H2O,Ce,La,Sm.Pr,Nd and Y,the absorption and translocation rate of phosphorus and rubidium in sugarcane were increased.After treatment of 300 ppm R(NO3)3·4H2O,the absorption and translocation rate of phosphorus and rubidium in sugarcane were increased too.Low concentration of RE increased the absorption and translocation rate and utilization efficiency of phosphorus and rubididm in sugarcane plant,but higher concentration of RE had a significant role of inhibition.After treatment of 200 ppm R(NO3) 3·4H2O,Ce,La,Sm,Pr,Nd and Y the root activity increased 22.33-44.54% compared with control.