Effects of lanthanum on growth and polyphyllin content of Paris polyphylla Smith var. chinensis (Franch.)Hara

Four-year-old Paris polyphylla Smith var. chinensis seedlings were cultured in five different concentrations (0, 5, 20, 80 and 160 mg/L) of lanthanum (La) solution. The effects of different application levels of La on the growth and rhizome saponin content were studied by comparing different vegetative growth indexes and components of rhizome saponins of P. polyphylla var. chinensis, as determined by HPLC. Results showed that La significantly impacted the growth and polyphyllin content of P. polyphylla var. chinensis. Polyphyllin content showed an increasing trend with the increase in La concentration; however, La concentrations of 160 mg/L inhibited P. polyphylla var. chinensis growth, which reduced plant height and increased specific leaf area. Overall, this study suggests that a La concentration of 80 mg/L is most conducive to the growth and accumulation of saponin in P. polyphylla var. chinensis.