Shoot tips (3–4 mm) were cut from young plants (7 days) and then placed on Petri dishes, on 12 inducing media. All media contained macroelements and a four times higher concentration of microelements as in MS medium, vitamins from B5 medium, 100 mg l-1 of myo-inositol, 0.5 g l-1 of proline and 3% sucrose. They differed with BAP content (2, 4, 6 mg l-1) and NAA (0.2, 0.4, 0.6 mg l-1). Explants were kept for 2 weeks in the dark at 23°C, then placed on MS medium complemented with 0.4 mg l-1 of BAP

more »

... and 0.04 mg l-1 of NAA, and brought to cultivation room. After 4 and 8 weeks, 2–3-leaved shoots were cut and placed in half-strength MS medium without hormones in order to root them. All three alfalfa varieties showed the ability for plant regeneration from the apical buds. Single shoots developed from explants induced on control mediums without cytokinin. The highest shoot regeneration efficiency (4.24–4.45) was observed after induction on media containing 2 mg l-1 of BAP. At the highest BAP concentration (6 mg l-1), the number of regenerated shoots decreased. Great differences as regarding the shoots regenerated by particular explants were observed (from 1 up to 11). About 52% of the shoots formed visible roots within 4 weeks. Almost 100% of the rooted plants transferred from in vitro cultures to pots survived.