Comparative study of in vitro regeneration efficiency of shoot-tip explants of Pelargonium graveolens and some cultivars of banana (Musa spp.) grown in Rwanda in response to different concentrations of cytokinins

This study examined the in vitro proliferation efficiency of shoot-tip explants from four cultivars of banana ( Musa spp ) and one species of Pelargonium graveolens . The explants were cultured on Murashige and Skoog (MS) medium supplemented with growth regulators. The comparative in vitro proliferation efficiency of banana cultivars was in the following order: Bluggoe > Injagi > FHIA-25 > Kamaramasenge, the comparative ratio was 10:7:4:2. The best number of shoot buds proliferation was observed on MS medium supplemented with 100 μM BAP while the quick buds development was observed on culture media with 10 μM BAP. The ANOVA proved that the genotype of explants of banana, the concentration in BAP and their interaction have high significant influence on their in vitro proliferation rate. Bluggoe, Injagi and FHIA-25 were described as subjects favorable for Rwanda’s in vitro propagation program of high-performance plant varieties. P. graveolens required high quantity of hormones and bit complicated disinfection compared to banana. For P. graveolens , the medium MS + 100 mM BAP + 1 mM NAA + 1 mM GA 3 was the best for in vitro regeneration while the addition of 10 and 100 mM Kin favored the rooting. The results of this study contributed a lot to the in vitro regeneration, with minimal explants material of banana ( Musa spp.) and P. graveolens currently carried out in Rwanda by ISAR and IRS, respectively. Key words: Banana cultivars, growth regulators, in vitro proliferation, MS medium, Pelargonium graveolens , ratio, cytokinin/auxin, Rwanda, shoot-tip explants.