矿山生态型和非矿山生态型粗齿冷水花富磷能力的比较

【目的】研究适宜施氮条件下磷富集植物粗齿冷水花的磷积累能力，可为有效利用该植物提取土壤中过剩的磷、减少磷的面源污染提供理论依据。【方法】以两种生态型粗齿冷水花 (Pilea sinofasciata) 为研究对象，进行土培盆栽试验，供试土壤为灰潮土，每盆 (8 L) 装土8 kg。分别施磷0、400、600、800 mg/kg，陈化8周。幼苗种植前，每盆施入140 mg/kg尿素。移栽9周后收获，测定植株生物量、磷含量，分析了土壤速效磷含量。【结果】1) 在供试施磷量范围内，两种生态型粗齿冷水花地上部、地下部生物量在施磷600 mg/kg时达最大，此时矿山生态型地上部、地下部生物量分别是其不施磷对照的2.37和3.69倍，非矿山生态型地上部、地下部生物量是其不施磷对照的4.63和7.36倍，矿山与非矿山生态型地上部生物量最大值分别可达28.6 g/株和31.9 g/株。矿山生态型生物量在不施磷和施磷400 mg/kg时显著大于非矿山生态型，在施磷600、800 mg/kg时两生态型间无明显差异。2) 随施磷量增加，两种生态型粗齿冷水花地上部磷含量和矿山生态型地下部磷含量均表现为先升高后降低，在施磷800 mg/kg时显著降低，而非矿山生态型地下部磷含量随施磷量增加而增加，在施磷800 mg/kg时达最高。各磷处理下，矿山生态型地上部磷含量均显著高于非矿山生态型，而地下部磷含量低于非矿山生态型。3) 高磷处理显著增加了两种生态型粗齿冷水花地上部、地下部磷积累量，且在施磷600 mg/kg时植株磷积累量最大，矿山生态型与非矿山生态型地上部磷积累量最高分别可达195 mg/株和182 mg/株。在不施磷和施磷400 mg/kg时，矿山生态型地上部磷积累量显著高于非矿山生态型，在施磷600、800 mg/kg时两生态型间无明显差异。4) 不同磷处理下，两种生态型磷富集系数远大于1，磷转移率大于80%；矿山生态型的磷提取率和移除量在不施磷和施磷400 mg/kg时均大于非矿山生态型，在施磷600、800 mg/kg时两生态型间无明显差异。【结论】适宜施氮条件下，粗齿冷水花在施磷600 mg/kg时表现出较强的磷富集能力。与非矿山生态型相比，矿山生态型在不施磷和施磷400 mg/kg时对磷的积累能力和富磷潜力更强；在施磷600、800 mg/kg时两生态型植株对土壤磷的富集能力无明显差异。

Comparison of phosphorus accumulation capacity in Pilea sinofasciata between mining ecotype and non-mining ecotype

【Objectives】The accumulation ability of phosphorus (P) in Pilea sinofasciata, a P-enrichment plant, was investigated to provide a theoretical basis for extracting excess P in soil.【Methods】The seedlings of P. sinofasciata were cultured in the pots in a greenhouse under natural light at Sichuan Agricultural University, Sichuan Province, China in 2017. The responsive effects of high phosphorus treatments including 400, 600, 800 mg/kg were analyzed by profiling the high-P tolerance and accumulation capability in P. sinofasciata under application of optimum nitrogen (N 140 mg/kg). The used soil was a typical calcareous alluvial soil containing various concentrations of phosphorus (P 0, 400, 600, 800 mg/kg) and cultured for 8 weeks, and total of 140 mg/kg of nitrogen was applied. After continuously culturing for another 9 weeks, the plants were harvested. Both the biomass and the phosphorus accumulation in plant were determined, and the available-P concentration in soil was analyzed.【Results】1) The biomass of shoot and root in both ecotypes significantly increased when supply of phosphorus was P 600 mg/kg, and then decreased under supply of P 800 mg/kg. Biomass of shoot and root in mining ecotype (ME) were increased 2.37 and 3.69 folds compared with the control under supply of P 600 mg/kg, respectively. And biomass of shoot and root in non-mining ecotype (NME) were increased 4.63 and 7.36 folds compared with the control under supply of P 600 mg/kg, respectively. The maximum shoot biomass in both the ME and NME were observed under supply of P 600 mg/kg, and were 28.6 g per plant and 31.9 g per plant, respectively. The biomass of shoot and root in the ME were significantly higher than those in the NME under supply of P 0 or 400 mg/kg. However, no difference was found under supply of P 600 or 800 mg/kg. 2)The phosphorus concentration in the shoot of both ecotypes and in the root of the ME significantly increased when supply of phosphorus was P 600 mg/kg, and decreased under supply of P 800 mg/kg. However, the phosphorus concentration in the root of the NME was increased when supply of phosphorus was increased to P 800 mg/kg. The phosphorus concentration in the shoot of the ME was significantly higher than that of the NME, but the phosphorus concentration in the root of the ME was lower than that of the NME. 3) The high phosphorus treatment significantly improved phosphorus accumulation in the shoot and root of two ecotypes. The maximum phosphorus accumulation in the shoot of the ME and NME occurred at supply levels of P 600 mg/kg, and were 195 mg per plant and 182 mg per plant, respectively. The phosphorus accumulation in the shoot of the ME was significantly higher than that of the NME under supply of P 0 or 400 mg/kg. However, no difference was found under supply of P 600 or 800 mg/kg. 4) Under the condition of phosphorus treatment, the bioaccumulation coefficient in both ecotypes was more than 1, while its translocation rate was higher than 80%. Moreover, the extraction rate and the removed phosphorus in the ME were higher than those in the NME under supply of P 0 or 400 mg/kg. However, no difference was found under supply of P 600 or 800 mg/kg.【Conclusions】Under condition of optimum N dosage, P. sinofasciata showed great P accumulation potentials under supply of P 600 mg/kg. The phosphorus accumulation capacity of the ME was higher than the NME under supply of P 0 or 400 mg/kg, however, no difference was found under supply of P 600 or 800 mg/kg.