Influence of salinity and temperature on the germination of Haloxylon recurvum Bunge ex Boiss

The stem succulent perennial halophyte Haloxylon recurvum Bunge ex. Boiss. grows and produces seed under highly saline conditions and seeds are deposited in saline soils. Experiments were conducted to determine the effect of salinity and temperature on the germination of seeds. Results indicate that seeds can germinate at very high salt concentrations (500 mM). However, highest germination percentages were obtained in distilled water. Cooler thermoperiods promoted germination, while high temperatures significantly inhibited the germination of seeds at all NaCl concentrations tested. Rate of germination decreased with increases in salinity. At higher thermoperiods the rate of germination was significantly lower in comparison to lower thermoperiods. Seeds recover after being transferred to distilled water and recovery was higher from higher salinity concentrations and lower thermoperiods. Final recovery germination percentages in high salt treatments were significantly lower than non-saline controls, indicating that exposure to high concentration of NaCl permanently inhibited germination. (C) 1996 Annals of Botany Company