Somatic embryogenesis and in vitro rosmarinic acid accumulation in Salvia officinalis and S-fruticosa leaf callus cultures

The effect of explant age, plant. growth regulators and culture conditions on somatic embryogenesis and rosmarinic acid production from leaf explants of Saliva officinalis and S. fruticosa plants collected in Greece was inves tigated, Embryogenic callus with numerous spherical somatic embryos could b e induced on explants derived from both species and cultured for 3 weeks on a Murashige and Skoog (MS) medium supplemented with 1.8-18 mu M 2,4-dichlo rophenoxyacetic acid (2,4-D) and kinetin (Kin) or 10.5-21 mu M 1-naphthalen acetic acid and 6-benzyladenine, Only explants from young plants (with six to eight leaves) responded to the culture treatments and, in general, low l ight intensities (50 mu mol m(-2) s(-1)) favoured callus formatian and indu ction of somatic embryos. Somatic embryos were further developed on the sam e medium. Heart-and torpedo-shaped embryos (1-2 mm long) were subcultured o n a growth-regulator-free MS medium for maturation, Maximum rosmarinic acid accumulation in S. officinalis and S. fruticosa callus cultured on 4.5 mu M 2,4-D and 4.5 mu M Kin was 25.9 and 29.0 g/l, respectively.