Ecophysiology and population biology of the perennial halophytic shrub Allenrolfea occidentalis (S. Wats.) Kuntze (Chenopodiaceae) growing in a salt playa near Goshen, northwestern Utah.

摘要

Allenrolfea occidentalis (S. Wats.) Kuntze (Chenopodiaceae) is a stem succulent halophytic shrub and is widely distributed in inland salt marshes and salt playas of the western United States. The effect of salinity, temperature, and growth regulating compounds on the seed germination, nutrient relations and ecophysiology of A. occidentalis plants in relations to salinity both in the field and laboratory conditions was investigated. The results indicated that the best germination of A. occidentalis occurred in distilled water and seeds could germinate up to 800 mM NaCl at warmer thermoperiod (25-35{dollar}spcirc{dollar}C). Germination percentage decreased with increase in salinity. High salinity did not affect the germination ability of seeds and the seeds promptly germinated when salinity stress was removed. Germination regulating chemicals (betaine, ethephon, fusicoccin, GA{dollar}sb3,{dollar} kinetin, nitrate, proline, and thiourea) were able to alleviate the salinity effect on seed germination. Growth of A. occidentalis was promoted at low density and at 600 to 800 mM NaCl. Growth promotion at above seawater concentration has not been reported before. Allenrolfea occidentalis is an ion accumulating, succulent halophyte and maintain progressively negative water potential with corresponding increase in soil salinity. Increase in the density of plants inhibited growth promotion.