Plant regeneration through leaf culture of Yacon

Abstract

Yacon (Smallanthus sonchifolius), a member of Asteraceae, is an ethnic food of Andeans. Interest in this crop is increasing because of its high fructo-oligosaccharide content in the tuberous roots. Due to the low productivity of viable seeds and virus infections through vegetative propagation, effective methods of in vitro propagation of yacon is being sought. To accomplish this, leaf pieces of yacon were cultured on the gelrite-solidified MS media, supplemented with various combinations of auxins and cytokinins. The most effective means of inducing calli was achieved on a MS medium that was supplemented with 0.1 mg·liter-1 2,4-D and 0.1 mg·liter-1 BAP. Shoot regeneration occurred when the calli were subcultured on the HaR medium (Paterson and Everett, 1985), supplemented with 1.0 mg·liter-1 BAP and 0.1 mg·liter-1 GA3. By sub culturing those calli at a monthly interval, the shoot regeneration continued up to the 10th subculture. The regenerated shoots rooted; the plantlets were well-acclimatized and transplanted successfully to the field. AFLP analysis conducted on the extracted DNA from the regenerants revealed 12 out of the 13 possessed different amplified fragments from those of the mother plants, indicating that the somaclonal mutation took place during the course of callusing and plant regeneration.