Seed germination characteristics of Halogeton glomeratus
Halogeton glomeratus (Bieb.) C.A. Mey, an annual forb in the family Chenopodiaceae, is widely distributed in the inland salt deserts of western North America. Experiments were conducted to determine the effects of NaCl and temperature on seed germination and the recovery of germination responses after transfer to distilled water. Seeds of H. glomeratus were germinated at various temperature regimes (515°C, 1020°C, 1030°C, 1525°C, 2030°C, and 2535°C), and salinities (0, 200, 400, 600, 800, and 1000 mM NaCl) in a 12 h dark : 12 h light photoperiod. Increases in NaCl concentration progressively inhibited seed germination, and this inhibition was more substantial in the dark than in the photoperiod treatment. Seed germination at concentrations higher than 800 mM NaCl was low (10%). Cooler temperatures significantly inhibited germination in all treatments. A temperature regime of high night (25°C) and high day (35°C) temperatures led to higher germination. Rate of germination decreased with an increase in salinity and was highest at 2535°C and lowest at 515°C temperature regimes. Seeds were transferred from salt solution to distilled water after 20 days, and those from high salinities recovered quickly at all temperature regimes. Recovery germination percentages from the highest salinity treatment varied from 51 to 100% at various temperature regimes.Key words: Great Basin desert, Halogeton glomeratus, halophyte, recovery of seed germination, salt deserts, temperature regime.