Effects of salinity and temperature on tuber sprouting and growth of Schoenoplectus nipponicus

Abstract

AbstractIn a scenario of climate change and intensive land‐use change, the issue of salt marsh degradation caused by global warming and soil salinization is becoming more serious. A climate chamber experiment was conducted to examine the responses of tuber sprouting and seedling growth of Schoenoplectus nipponicus to variations in the temperature regimes (20/10, 25/15, 30/20 and 35/25°C; 12‐h light/dark 12‐h photoperiod) and different salt concentrations (0, 50, 75, and 100 mmol/L salinity). Results showed that the final sprouting percentage decreased with the increase in salinity and increased with the rising temperature. Salinity lower than 50 mmol/L was the most favorable for tuber sprouting. Under high salinity (75 and 100 mmol/L salinity), the inhibition of tuber sprouting at 20/10°C was greater than other temperature regimes. Along the temperature gradients, both plant height and leaf N content increased, and root length decreased under non‐saline‐alkali conditions, while plant height, leaf N content, and root length declined significantly under salt stress (50, 75, and 100 mmol/L salinity). With the increase in temperature, the production of tubers under the control treatments was enhanced significantly, but that under salt stress declined significantly. Under 0 mmol/L salinity, the accumulation of biomass in various organs increased with rising temperature. Biomass accumulation increased first and then declined for plants grown under salt stress, with a peak value of 25/15°C. Root: shoot ratio was reduced significantly under the combination of high salt stress (75 and 100 mmol/L salinity) and high temperatures (30/20°C and 35/25°C). Our study will contribute to a better understanding of the influence of climate warming and increasing serious human disturbances on this important wetland species.