Seed germination and metal accumulation of Moso bamboo (Phyllostachys pubescens) under heavy metal exposure

Abstract

Along with the increase of economics, heavy metal pollution in soil directly threatens food production security, and the toxicity affects humans because of their longevity and accumulation in organs. Phytoremediation is a new technology that usually employ hyperaccumulator plants to remove pollutants from environment or to render them harmless. The biomass of hyper鄄accumulators discovered before are less, and as a result in actual applications the hyper鄄accumulators are restricted significantly. Moso bamboo ( Phyllostachy pubescens) is not hyperacculator specie, but it has several advantages compared with hyperaccumulators. Moso bambo grows quickly, reaching maximum size within two months with an average height of 15m. In present paper the seeds of Moso bamboo are taken as test materials, the toxicity effects of four heavy metals involving Pb 2+ , Zn 2+ , Cu 2+ and Cd 2+ on seed germination and its accumulation of heavy metals were studied. The results indicated that: (1) The addition of Pb 2+ and Cd 2+ inhibited the germination rate, germination energy, germination index and vigor index of Moso bamboo seed significantly. For the low treatment level of Cu 2+ and Zn 2+ , the germination rate, germination energy, germination index and vigor index increase significantly, while the results were on the contrary for the high treatment level. When the treatment dosage reached to 1600 滋mol / L, the Cd 2+ addition has strong inhibition on seed germination than other three heavy metals. (2) The addition of low levle of Pb 2 + and Zn 2+ would promote the root growth significantly, while with the stress of Cu 2+ and Cd 2+ the root morphology are inhibited. (3) The concentration of Pb 2+ , Zn 2+ , http: / / www.ecologica.cn Cu 2+ and Cd 2+ in shoots of Moso bamboo reached 6810.51, 1387.77, 951.77 and 429.33mg / kg respectively after treating for 10 d. The translocation factor dimension is Zn 2+ >Cd 2+ >Pb 2+ >Cu 2+ , and the tolerance order of bamboo seedlings to heavy metal is: Zn 2+ >Pb 2+ > Cu 2+ >Cd 2+ . In summary, the results of above all would provide useful reference for soil test in future, and it also opens a new perspective for the study of phytoremediation species selection.