In vitro effects of gibberellic acid and sucrose concentration on micropropagation of two elite sweet potato cultivars in Rwanda

The current study aimed at evaluating the effect of gibberellic acid (GA3) and sucrose on in vitro propagation of two elite sweet potato cultivars (Ukerewe and Gihingamukungu). Nodal explants from in vitro growing plantlets were harvested and cultured on Murashige and Skoog media supplemented with 2.5, 5, 10, 20 and 40 μM, GA3. In a separate experiment, sucrose was evaluated at 30, 60, 90, 120, 150, 180 and 210 mM. For Ukerewe, the explants cultured on medium supplemented with 10 µM GA3 recorded the longest (2.78 ± 0.36 cm) microshoots.. On the other hand, cultivar Gihingamukungu explants cultured on media supplemented with 2.5 GA3 µM produced the longest ((3.23 ± 0.40 cm) microshoots. Nodal explants from the two cultivars cultured on media supplemented with sucrose 150 mM yielded the longest microshoots (2.51 ± 0.26 and 2.34 ± 0.24 cm, respectively). From the results of the current study, it can be concluded that for micropropagation of the cultivar Ukerewe 10 µM GA3 should be used while 2.5 GA3 µM should be used for micropropagtion of cultivar Gihingamukungu. The regenerated plantlets were successfully weaned in the greenhouse. The protocol developed in this research will open new prospects for massive propagation of the elite sweet potato cultivars in Rwanda.