不同磷处理下两种生态型粗齿冷水花的富磷特征及根系形态差异

Phosphorus accumulation and root morphological difference of two ecotypes of Pilea sinofasciata grown in different phosphorus treatments

采用水培试验,以矿山生态型和非矿山生态型粗齿冷水花为材料,设置50,100,200,400和800 mg/L五个磷处理,探讨2种生态型粗齿冷水花对磷的富集能力以及根系形态的差异。结果表明,1)随着供磷浓度的增加,2种生态型粗齿冷水花生物量均呈先增高后降低的趋势,并在磷400 mg/L时最大;而不同供磷浓度下,均表现为矿山生态型生物量高于非矿山生态型。2)2种生态型粗齿冷水花根、茎、叶磷含量随着供磷浓度的增加而增加,且矿山生态型高于非矿山生态型,其中叶片磷含量最高能达到22.85 g/kg。3)在一定范围的高磷水平下,矿山生态型粗齿冷水花的总根长、根系表面积、根系总体积和侧根数均大于非矿山生态型,而平均直径差异不大。表明高磷条件下矿山生态型粗齿冷水花具有较好的富磷能力,而良好的根系形态是其富磷的重要特征。

Elevated phosphorus （P） concentrations in surface runoff from P-enriched agricultural soils have been commonly considered an important cause of the eutrophication of freshwater bodies. Plant-assisted approaches have proven effective in ameliorating the ecological hazards of excessive soil P. A hydroponic experiment was carried out to investigate the phosphorus （P） accumulation and root morphological difference of the two ecotypes of Pilea sinofasciata grown under five （0, 100, 200, 400 and 800 mg/L） P levels. The biomass of the mining ecotype （ME） of P. sinofasciata was significantly higher than that of the non mining ecotype （NME）. Biomasses of both ecotypes initially increased but then decreased with increased P concentration. The highest biomass （400 mg/L） and P concentrations of root, stem, and leaf of both ecotypes increased with P concentra- tion. P concentration of the ME was higher than that of the NME and peaked at 22. 85 g/kg. Total root length, total root surface area, total root volume and number of lateral roots of the ME were higher than those of the NME. With an increase in P concentration, total root length, total root surface area, total root volume and number of lateral roots of the ME initially increased but then decreased. The average root diameters of the ME and NME were not significantly different at high P levels, and the difference between ecotypes was not sig- nificant. These results indicate that overall, ME has better P accumulation than NME and better root morpho- logical characteristics such as total root length, total root surface area, total root volume and number of lateral roots, features that are important for a high P uptake ability. It confirmed that the ME ecotype of P. sinofhsci ata has superior efficiency for removing P from hydroponic conditions and could be a potential choice for cleaning P from contaminated water.