Comparison of phosphorus uptake and accumulation capacity among three plant species

Abstract

Aims Phosphorus mining wasteland is a very special kind of degraded ecosystems, where vegetation and land- scape are severely damaged. Our objective was to select plants suitable for phytoremediation of phosphorus-rich soils in mining wasteland. Methods We conducted pot experiments to investigate phosphorus uptake and accumulation capacity in Helian- thus annuus, Sorghum sudanense and Cucurbita moschata grown in soils with different levels of phosphorus sup- ply. The phosphorus concentrations applied are 0, 100, 300, 500 and 700 mg·kg -1 . Phosphorus concentration, phosphorus accumulation, bioaccumulation and translation coefficient of the plants were measured for three growth periods (4 weeks, 7 weeks, 10 weeks), respectively. Important findings Over the same growth period, phosphorus concentration in shoots of the three plant species increased with increasing phosphorus supplies, with the maximum of 9.67 g·kg -1 in H. annuus, 4.86 g·kg -1 in S. sudanense, and 6.32 g·kg -1 in C. moschata. Under the same phosphorus treatments, phosphorus concentration sig- nificantly increased with growth time in shoots of H. annuus, decreased in shoots of S. sudanense, and did not significantly change in shoots of C. moschata. The aboveground total phosphorus accumulation in the three plant species all reached highest values when grown for 10 weeks in soils supplied with 700 mg·kg -1 phosphorus, amounting to 217.83 mg·plant -1 in H. annuus, 93.92 mg·plant -1 in S. sudanense, 135.82 mg·plant -1 in C. mo- schata, respectively. The bioaccumulation and translation coefficients in both H. annuus and S. sudanense ex- ceeded 1.00 under each treatment. The peak values of the two coefficients were 11.39 and 4.09 for H. annuus. In conclusion, the phosphorus uptake and accumulation capacity of the tested plant species were in the order of H. annuus > C. moschata > S. sudanense, and H. annuus can be a possible candidate for phytoremediation of phos- phorus mining wastelands.