HIGH FREQUENCY REGENERATION OF CRITICALLY ENDANGERED ENDEMIC PLANT CENTAUREA LYCAONICA

Abstract

Centaurea lycaonica is a critically endangered endemic plant species found in Turkey. In this study in vitro culture techniques were evaluated as an ex situ strategy for conservation of this species. Achenes were surface sterilized and cultured either in MS medium alone or along with GA(3) in an attempt to induce germination. It was observed that the overall germination rate was low and that the highest rate (20%) was obtained when hormone-free MS medium was used. For axillary shoot pro-pagation, nodal explants were cultured on MS me-dium supplemented with BAP, Kin or TDZ. The highest shoot number (8.7 shoots per explant) was obtained on MS medium supplemented with 0.5 mg L BAP. Leaf explants were removed from the in vitro axillary shoots that were used as explants and cultured on medium including BAP, Kin, TDZ alone or with NAA. The calli obtained exhibited differences in morphology which appeared to be dependent on type and combination of PGR used. It was found that BAP was the only PGR that was capable of eliciting a positive response with respect to shoot regeneration. The highest shoot number (32.3 shoots per explant) was obtained on MS medium supplemented with 0.5 mg L-1 BAP and 0.2 mg L-1 NAA. Regenerated shoots were transferred into various rooting media. The best rooting rate (90%) was obtained on MS medium supplemented with 2 mg L-I IAA. Rooted shoots were successfully acclimatized and were observed to grow vigorously under ex vitro conditions.