Effects of NaCl stress on element contents and accumulations of four landscape plant species

Objective  To investigate the effects of NaCl stress on element contents and accumulations of Hibiscus rosa-sinensis, Ixora chinensis, Schefflera arboricola and Cordyline fruticosa, and provide a scientific basis for nutrient management of plants under NaCl stress.

Method  The above four landscape plant species were selected as materials and treated by three NaCl concentrations (0, 0.3% and 0.6%) to analyze the contents and accumulations of Na, Cl, N, P, and K in these plants.

Result  The contents of Na, Cl, N, P, and K in different organs of above landscape plants ranged from 0.30 to 19.66, 0.12 to 25.79, 5.72 to 23.86, 0.92 to 2.86 and 6.77 to 26.67 g·kg^–1, respectively. NaCl stress greatly increased Na and Cl contents in different organs of four species. N contents in all organs of H. rosa-sinensis and I. chinensis significantly increased with the increase of NaCl stress concentration. N contents in all organs of S. arboricola and C. fruticosa, P contents in all organs and K contents in leaves and stems of four species varied irregularly. K contents in roots of four species decreased. NaCl stress increased Na accumulations in all organs of four species (except that in roots of S. arboricola), and Cl accumulations in all organs of H. rosa-sinensis, I. chinensisand C. fruticosa, and decreased N accumulations in all organs of four species except that in roots of H. rosa-sinensis, and P and K accumulations of four species. The change ranges of Na and Cl accumulations were greater than those of N, P and K under NaCl stress, and Na and Cl mainly accumulated in leaves and stems. The ratios of K⁺/Na⁺ in all plant organs decreased with the increase of NaCl stress concentration except that in roots of C. fruticosa. The decrease ranges of K⁺/Na⁺ ratio in leaves and roots of H. rosa-sinensis, S. arboricolaand C. fruticosa were less than those in stems, while those in all organs ofH. rosa-sinensisand S. arboricolawere less compared with I. chinensisandC. fruticosa.

Conclusion  In these four landscape plants, H. rosa-sinensis and S. arboricola have relatively stronger salt-resistance abilities.