Germination of two native wheatgrass (Agropyron) species under different temperature and water potential regimes

Abstract

Native wheatgrass species are important for land reclamation or rangeland re-seeding. The objective of this study was to evaluate seed germination of slender wheatgrass (Agropyron trachycaulum Link Malte) and northern wheatgrass (Agropyron asystachyum (Hook.) Scribn.) under different temperatures and water potentials. Over a 10 d period, germination was studied in four growth chambers with constant temperatures of 5, 10, 20 and 25°C and water potentials of –1.0, –0.8, –0.6, –0.4, –0.2 and 0.0 Mpa at each temperature. Two wheatgrass species showed a good germination at or higher than –0.4 Mpa water potentials when temperature was 20-25°C, but the percentage was reduced at or lower than –0.6 Mpa. Compared to northern wheatgrass, higher percent of seed germinated for slender wheatgrass at lower water potential, but slender wheatgrass required higher germination temperature.