Micropropagation of Solanum quitoense var. quitoense by apical bud, petiole and hypocotyl culture.

The development of in vitro propagation methods can improve the current commercial use and conservation of plants like naranjilla (Solanum quitoense), a distinctive Andean crop and key emerging agricultural product. In the present study, we report in vitro culture protocols for naranjilla apical buds, hypocotyls and petioles. In apical bud culture, MS medium supplemented with 0.10 mg l-1 1-naphtaleneacetic acid (NAA) produced longer plantlets with greater number of leaves. Hypocotyl culture yielded higher number of shoots when using older explants in MS medium supplemented with different combinations of NAA, 6-benzylaminopurine (BAP) and gibberellic acid (GA3). Petiole culture produced a significantly higher number of shoots per explant, with more abundant and bigger leaves, when using MS medium supplemented with 0.02 mg l-1 NAA, 4.50 mg l-1 BAP and 1.00 mg l-1 GA3. A factorial analysis reveals that the interaction between GA3 and NAA/BAP plays an important role in shoot regeneration. These results provide new tools for the in vitro regeneration of naranjilla plants, improving on previously reported protocols for this species by using alternative explant types and regeneration protocols.