砂培条件下橡胶树砧穗间矿质养分的积累与分布

在砂培条件下对橡胶树砧穗间几种矿物质养分的积累和分布情况进行研究。研究结果如下：（1）砂培后植株中N、P、K、Ca、Mg含量均有不同程度的增加，但在无外源养分供应条件下，随着接穗的生长，N、P、K、Mg含量增加幅度减小并影响植株正常生长。（2）外源矿质养分利用水平因不同生长阶段而异，N和Ca在第二蓬叶时才开始利用，K和Mg在第一蓬叶时大量利用，而此时P素的利用很少。（3）矿质养分在砧木不同部位和位置的含量水平和分布有明显的差异。韧皮部中累积较多的养分，而Mg主要分布在木质部上部，P主要分布在韧皮部下布。

Accumulation and Distribution of Mineral Nutrition in the rootstock and scion of Hevea Brasiliensis under Sand culture

A study on the accumulation and distribution of several mineral nutrients in the rootstock and scion of Hevea Brasiliensis under sand cultural conditions. The results are as follows： （1） The contents of N, P, K, Ca, Mg were increased in different degrees under sand cultural conditions, but with the growth of scion in the absence of exogenous nutrients, the increment of N, P, K, Mg contents was increased and the normal growth of rubber seedlings was influenced. （2） The capability of utilization for exogenous mineral nutrients varies due to different growth stages, N, and Ca start to bc utilized in the second leaf-whorl stage, K, Mg in the first leaf-whorl stage and the utilization rate of P element was very few at that time. （3） The content level and distribution of mineral nutrients in the different parts and positions of rootstock and scion have significant differences. More nutrients were accumulated in phloem, while Mg is mainly distributed in the upper part of xylem, P mainly distributed in the lower part of phloem.