Responses of Portulaca oleracea Linn. to selenium exposure

摘要

The present study was investigated to evaluate the uptake and accumulation of selenium (Se) by the stem cuttings of Portulaca oleracea L. grown in alfisol amended with various concentrations of Se. P. oleracea accumulated a maximum of 63.4 mu gg(-1) dry weight in a short growth period of 42days. The order of accumulation of Se among the plant parts was leaves (31.5gg(-1))>stems (16.4gg(-1))>roots (15.5gg(-1)). The accumulation potential was fourfold higher than the plant available concentration of 15.2gg(-1) of Seg(-1) of soil (diethylenetriaminepentaacetic acid extracted). Although the plant was able to accumulate Se in their tissues, increase in Se concentrations in soil caused a concentration-dependent decrease in the growth rate of plants (regeneration of leaves, number of leaves, number of roots, root length, stem length and biomass).