Conditions and stimulation for germination in Bromus auleticus seeds

Abstract

Bromus auleticus Trin. ex Nees is a perennial species with high forage production, good nutritional quality in a critical period of the year (autumn – winter), and long persistence. This work studied: I) the effect of temperature and light on B. auleticus seed germination, II) the effect of laboratory seed treatments on germination stimulation immediately after harvest. In I), three alternating temperatures: 20-30, 15-25 and 10-20°C (the lower temperature maintained by 16 hours), and two constant temperatures: 10 and 20°C were tested. Light treatments were: a) no light, and b) 8 hours of light followed by 16 hours of darkness. The following treatments were tested to stimulate germination: a) control: with distilled water, b) 0.2% potassium nitrate solution instead of water, c) 0.05% gibberellic acid solution instead of water, and d) prechilling at 7°C for 7 days. Results showed that B. auleticus can germinate in a range of temperatures between 10 and 25°C, either constant or alternating, with light or without it. For germination trials, constant temperature at 20°C gave the highest germination velocity. Germination was increased by prechilling and use of gibberellic acid, probably because of the hormonal nature of dormancy in this species.