An effective procedure for producing transformed Centaurium erythraea plants from synthetic seeds is described. Explants were encapsulated in 3% sodium alginate with 3% sucrose. Encapsulated hairy roots were cultured on half-strength Murashige and Skoog (1/2 MS) or Woody Plant (WPM) agar-solidified regeneration media supplemented with 6-benzylaminopurine (BAP) or without the cytokinin. The use of WPM with 0.5 mg/L of BAP gave the best shoot formation frequency (86%) and mean number of shoots

more »

... ) per root segment. Shoots rooted with 97% frequency on 1/2 MS without growth regulators. Encapsulated shoot buds were cultured on onethird-strength MS agar medium (1/3 MS) supplemented with indole-3-butyric acid (IBA) (0.05 mg/L). The plantlet conversion frequency was 32%. The encapsulated hairy roots and shoot buds were stored for 4, 6 or 14 weeks at 4°C. Synthetic seeds encapsulated with 3% sodium alginate with 3% sucrose stored at 4°C remained viable for 6 weeks but their developmental parameters significantly decreased. Adding nutrient medium and growth regulator to the alginate matrix increased plantlet recovery from both non-stored and stored synthetic seeds: synthetic seeds retained their viability and ability to form plantlets even after 14 weeks of storage. Regenerated transformed plantlets of C. erythraea were acclimatized in the greenhouse. K Ke ey y w wo or rd ds s: : Centaurium erythraea, hairy roots, transgenic plants, synthetic seeds. * 3% SA + 3% S -3% sodium alginate + 3% sucrose ** 3% SA + M -3% sodium alginate + 3% sucrose + 1/3 MS medium with IBA (0.05 mg/L) Values bearing the same letter within column do not differ significantly at P≤0.05 by the Mann-Whitney U-Test. Data are means ± SE of 3 replicated experiments.