Breaking seed dormancy and micropropagation of perennial vulneraria milkvetch (Astragalus vulnerariae DC.)

In this study, an efficient system to break seed dormancy and plant regeneration was established for perennial vulneraria milkvetch (Astragalus vulnerariae DC.). The seed coat dormancy could be easily released using 40% sulphuric acid treatment for 15 minutes, which made the seed coat permeable without damaging zygotic embryos. The tissue culture studies reported regeneration on 5 explants, which had variable effects on shoot regeneration, using MS medium containing variable concentrations of Kin–NAA and BAP–NAA. Maximum shoot regeneration of 86.67% with 4.47 shoots per explant was noted on MS medium containing 0.5 mg·l–1 Kin – 0.5 mg·l–1 NAA on hypocotyl explants. No shoot regeneration was noted on cotyledon leaf and shoot nodes using MS medium containing any concentration of BAP–NAA. Maximum shoot regeneration of 50% with 3 shoots per explant was also observed on 1 mg·l–1 BAP – 0.5 mg·l–1 NAA on epicotyl explants. MS medium containing Kin–NAA induced hypocotyl explant shoots had rooting percentage of 36.67% on 0.5 mg·l–1 IBA, whereas, MS medium containing BAP–NAA induced hypocotyl shoots had rooting percentage of 46.67%. The in vitro cultured plants had an acclimatization rate of 78%. Aesthetically attractive, economical, easy to maintain and water efficient vulneraria milkvetch is currently not available in landscaping. The system of plant regeneration and adaptation suggested by this paper may help to dissipate it to a broad range of water scarce environments as a sustainable and inexpensive choice.