高磷对矿山生态型水蓼磷富集特性的影响

Effect of high phosphate supply on P accumulation characteristics of mining ecotype of Polygonum hydropiper

采用土培试验,以磷富集植物矿山生态型水蓼为研究对象,研究了高磷条件下(P 800 mg/kg)矿山生态型水蓼4周、8周、12周的磷富集特性,为利用矿山生态型水蓼提取土壤或水体中过量的磷,防治磷的非点源污染提供理论依据。结果表明,1)高磷处理下,矿山生态型水蓼根干重在4周、8周、12周时分别为不施磷处理的4.50、8.12、3.17倍;茎干重分别为不施磷处理的6.83、11.47、15.14倍;叶干重分别为不施磷处理的5.77、10.49、7.11倍。矿山生态型水蓼生物量在12周达到最大,增加幅度明显高于非矿山生态型。2)高磷处理下,矿山生态型水蓼各器官磷含量明显高于不施磷处理,且随着生长期延长逐渐降低。矿山生态型水蓼磷富集系数均大于1,且在高磷处理下高于非矿山生态型。各生长期下,矿山生态型磷迁移率均大于50%,且在高磷处理下分别为不施磷处理的1.21、1.21、1.20倍。矿山生态型水蓼地下部与地上部磷积累量在12周时,分别达到9.76、105.12mg/plant,DW,为非矿山生态型的2.29、3.29倍。3)矿山生态型水蓼根系酸性磷酸酶活性在8周时达到峰值,在4周和8周时表现为高磷处理大于不施磷处理且显著高于非矿山生态型(P<0.05)。而植酸酶活性随生长期延长逐渐降低,在12周时表现为高磷处理大于不施磷处理且高于非矿山生态型。表明在高磷处理下,矿山生态型水蓼对磷具有较强的吸收和积累能力,是一种理想稳定的磷富集材料。

In order to provide a theoretical basis for extracting the excess phosphorus（P） in soil or water, preventing non-point source pollution, it was necessary to determine the P accumulation characteristics in a mining ecotype（ME）of Polygonum hydropiper screened as P enrichment plant earlier, with a nonmining ecotype（NME）as contrast. Pot experiments were carried out in a screenhouse on the farm of Sichuan Agricultural University, Sichuan province, China in 2011. The effect of P-enriched treatment （P 800 mg/kg） on the characteristics of P accumulation in the ME of P. hydropiper at different growth periods（4 weeks, 8 weeks, 12 weeks）was analysed. 1）With growth period prolonged, the biomass of root, stem and leaf in the ME of P. hydropiper ascended and reached a maximum in 12 weeks at P-enriched condition. The increment of the ME was significantly higher than that of the NME additionally. Dry weight of root of the ME with P-enriched treatment was 4.50, 8.12 and 3.17 times compared with control at 4, 8 and 12 weeks respectively; and that of stem was 6.83, 11.47 and 15.14 times respectively; while that of leaf was 5.77, 10.49 and 7.11 times respectively. 2）Each organ of the ME with P-enriched treatment showed a significantly higher P concentration comparing with control, and the P concentration generally showed decreasing trend with the growth period prolonged. Bioaccumulation coefficient of the ME was more than 1; moreover, the ME was apparently higher than the NME. While its translocation rate was more than 50%, and the ME with P-enriched treatment was significantly higher which was 1.21, 1.21 and 1.20 times of the no phosphate treatment, respectively. Besides, P accumulation in root and shoot of the ME with P-enriched treatment reached 9.76 mg/plant, DW and 105.12 mg/plant, DW respectively, which were 2.29 and 3.29 times higher than the NME at 12 weeks. 3）Activity of acid phosphatase （Apase） in the ME reached its peak at 8 weeks. Compared with control, the ME was obviously higher, and it was significantly higher than that of the NME with P-enriched condition at 4 weeks and 8 weeks（P〈0.05）. Nevertheless, phytase activity in the ME gradually dropped with the growth period prolonged, while it showed higher with P-enriched treatment than that of control only at 12 weeks, and the ME was higher than the NME. The ME of P. hydropiper shows high absorption capacity and accumulation ability of P under P-enriched condition. Thus, it can be used as a kind of ideal and stable P enrichment material.