Studies On Physiological Characteristic And Turf Establishment Under Sea-Salt Stress In Paspalum Vaginatum

Seashore paspalum(paspalum vaginatum) is a perennial warm-season turfgrass, which usually grow in seashore sand and has tremendous salt tolerance. It can normally grow in soils with salt content of 0.25%. Moreover, seashore paspalum is excellent in the resistence of drought, waterlogging, shade and trampling. There are 300,700km~2 saline land in China and the establishment of turf in saline land is continually expanding. In this experiments, growth and morphological characteristics, the content of ion and changes in antioxidant system of leaves in seashore paspalum (cv:Adalay)were studied in a pot experiment under 0, 6.8, 13.6, 20.4, 27.2 and 34g/L sea-salt concentration. Turfgrass establishment methods under sea-salt stress were also preliminarily researched.The results showed that, the width of leaf, diameter of erect and stolon, dry weight of root, stem and leaf decreased significantly with sea salt concentration increasing and negative correlated significantly (p<0.01) with conductivity value of sea-salt solution.The content of Na~+ in leaf and stem increased with sea-salt concentration increasing. The content of Na~+ in root under 6.8g/L sea-salt stress was not significantly changed compared with control. And the concentration of Na~+ under the other treatments were higher significantly (p<0.05)than that under control and sea-salt concentration of 6.8g/L. The content of K~+ in leaf was almost 25mg/g with salinity increasing. The content of K~+ in stem was decreased gradually with sea-salt concentration increasing .The maximum content of K~+ in root reached 6.4mg/g at the sea-salt concentration of 20.4g/L. However, it decreased when the sea-salt concentration reached 34g/L, which was still higher than that of control.With sea-salt concentration increasing, the content of water and chlorophyll in leaf decreased. Activity of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) increased. Activity of CAT did not differ significantly among the treatment above 6.8g/L salt concentration. SOD and CAT activity basically showed stable after 14 days salt treatments. POD activity was stable after 21 days salt treatment except 34 g / L sea-salt stress. The content of malondialdehyde(MDA) increased gradually with increasing sea-salt concentration and prolonging stress days. The content of MDA was stable after 21 days under sea-salt stress. Proline (Pro)accumulated under 20.4, 27.2 and 34g/Lsea-salt concentration stress and the accumulation is proportional to the sea-salt concentration.Time of turf formation prolonged with increasing sea-salt concentration by plugging and stolonizing establishment methods. The plugging has less time of turf formation than stolonizing under the same sea-salt concentration stress. The plugging can form turfgrassland but stolonizing can not under 20.4g/L and 27.2g/L sea-salt stress. Area of turfgrassland could not extend under 34g/L sea-salt stress through the two turf establishment methods. The growth rate of erect , dry weight of above-ground and under-ground part , height of turf by two turf establishment decreased with increasing sea-salt concentration. The growth rate of stolon under 13.6g/L and 20.4g/L sea-salt stress was significantly (p<0.01) lower than that under control and 6.8 g / L sea-salt stress.