磷对超积累植物——东南景天生长和积累锌的影响

Effects of phosphorus on the growth,zinc absorption and accumulation in hyperaccumulator-Sedum alfredii Hance

通过溶液培养试验 ,探讨了东南景天植株体内磷锌相互关系 .结果表明 ,在一定范围内供磷 ( 0 5— 2 0mmol·L- 1)能明显促进东南景天的生长 ,显著提高叶片、茎和根的生物量 .适当的增磷 ( 0 5— 1 0mmol·L- 1)极显著提高东南景天叶片、茎的锌含量和地上部的锌积累量 ;高磷 ( 2 0mmol·L- 1)则降低地上部的锌含量和积累量 .无论在何种磷锌水平处理下S(地上部的锌积累量 ) R(根系的锌积累量 )比值始终大于 1,表明在东南景天植株体内可能存在明显的“增磷诱导锌需求 (Phosphorus inducedzincrequirement)”现象 .从植物修复角度来说 。

In this paper,we investigated the interactions between P and Zn in Sedum alfredii Hance in hydroponic culture to compare with a non-hyperaccumulator Sedum emarginatum Migo.Biomass (dry matter) of leaves,stems and roots of Sedum alfredii Hance increased significantly with increasing P supplies from 0.5 to 2.0mmol·L^(-1) at all Zn levels.Zn contents and amounts of Zn accumulated in leaves,stems and roots of Sedum alfredii Hance increased significantly with increasing P concentrations in nutrient solution (for leaves and stems from 0.5 to (1.0mmol·L^(-1),)for roots from 0.5 to 2.0mmol·L^(-1)) at all Zn levels,and a higher P supply at 2.0mmol·L^(-1) remarkably reduced Zn concentrations and accumulation in leaves and stems of Sedum alfredii Hance.It was also found that there were a higher ratio of shoot Zn accumulation/roots Zn {(S/R>1)} in any P and Zn treatments,suggesting that appropriate P application enhanced Zn absorption,translocation from root to shoot and accumulation in shoots of Sedum alfredii Hance.From these results indicated that “phosphorus-induced Zn requirement” was evident in Sedum alfredii Hance.With respect to phytoremediation,the application of P at appropriate rates may be useful approach to enhancing the growth and Zn accumulation in Sedum alfredii Hance for phytoremediation of the Zn-contaminated soils.