THE EFFECT OF SALINITY AND TEMPERATURE ON THE GERMINATION OF POLYMORPHIC SEEDS AND GROWTH OF ATRIPLEX TRIANGULARIS WILLD.

Abstract

Polymorphic seeds of Atriplex triangularis were germinated at various temperatures (5–15 C, 5–25 C, 10–20 C, 20–30 C) and salinity regimes (0 to 1.5% NaCl) in order to determine their germinability and early seedling growth under these conditions. Larger seeds generally had a higher germination percentage in saline medium. The rate and percentage of germination decreased with increased salinity stress. A thermoperiod of 25 C day and 5 C night, 12 hr/12 hr, temperature enhanced germination of seeds. Early seedling growth is promoted in larger seeds at lower salinity, and at high‐day and low‐night temperatures. Polymorphic seeds have different physiological requirements which provide alternative situations for seed germination in natural habitats.