Seed priming on germination and establishment of Astragalus brachyodontus species efficiency in greenhouse under water stress conditions

Early establishment of rangeland plant species, especially in arid and semi-arid regions, is a considerable issue to increase their yield. In order to investigate the effects of seed priming on changes in yield of the Astragalus brachyodontus pasture species, the present study was carried out in the greenhouse with factorial design. Three treatments of hydro-priming (distilled water), osmopriming (Polyethylene Glycol with two levels of -0.4 and -0.8 MPa) and hormone priming (gibberellic acid) as the first factor, and three levels of deficit irrigation stress (100% field capacity, 75% field capacity and 50% field capacity) were considered as the second factor and 3 populations (Zanjan, Qom and Khalkhal) as the Third factor with 3 replications. The results showed that seed priming, deficit irrigation stress, populations and their interactions had a significant effect at the 1% probability level on all investigated traits. The soil water reduction caused a significant decrease in seedling germination percentage, stem length and weight, but the root length increased and the root weight first increased and then decreased intensively. The maximum yield of height (11.0267 cm), root length (30.6467 cm), stem weight (1.1700 g) and root weight (1.3664 g) was related to Zanjan population in normal irrigation. The treatment of -0.4 MPa osmopriming had the highest values in root length (33.1556 cm), stem weight (1.2144 g) and root weight (1.4800 g). Generally, according to the present research, -0.4 MPa osmo-priming and hormone priming with gibberellic acid were introduced as treatments to improve the Astragalus brachyodontus species performance in the greenhouse under the severe deficit irrigation stress condition. This results can be considered to improving the establishment and performance of this native valuable forage, in breeding programs and rangeland development, to improve its initial establishment in deficit irrigation conditions.