Optimization of Direct Regeneration of Astragalus verus in in vitro condition

Abstract

Astragalus is one of the most valuable medicinal plants in Iran. The species of Astragalus verus is a native species of tragacant producer. Due to the importance of this species in the production of tragacant, exposed to extinction, the role of seed in its reproduction, as well as the possibility of its reproduction using micropropagation, this study was conducted with the aim of breaking seed dormancy, seed germination and direct regeneration of this plant. First, the effect of surface scratching on breaking of seed dormancy was investigated. Then, the effect of culture medium and sucrose concentration on seed germination and sterile seedling production was studied as factorial based on completely randomized design. The explants of hypocotyle and epicotyle were cultured on MS medium supplied by B5 vitamin containing BAP in 3 levels and IAA in 2 levels due to multiple shoot production. Rooting of multiple shoots was carried out on 1/2MS medium containing IAA in 2 levels and IBA in 3 levels based on completely randomized design with 6 treatments and 5 repeat.Scraping increased the germination rate by an average of 98%. Different media and sucrose concentration had no effect on germination percentage. With increasing sucrose, were increased the stem and root length, fresh weight and seedling dry weight. The highest percentage of shoots was obtained in MS medium containing 2 mg /L BAP without IAA with an average of 4.6 pcs. The highest percentage of rooting was obtained with 1.5 mg/l IAA with an average of 60%. The results of this study can be used in micropropagation, gene transformation and in vitro tragacant production.

Keywords

• astragalus verus
• germination
• multiple shoot induction
• rooting
• seed dormancy