Best practices for initiation of banana and plantain (Musa spp.) cultures

Banana is a staple food and income crop world-wide. Here, we identified the best practices for the initiation of banana (Musa spp.) cultures. The cultivars studied included East African highland bananas (Mshare/Mchare and Nshakara) and plantains (Mzuzu), which are highly demanded by farmers. The following factors were assessed: sterilization techniques for rainy and dry seasons, explant size, effect of benzylaminopurine (BAP) concentration on regeneration of cultures, effect of ascorbic acid on culture browning, and culturing conditions. We found that treatment with ethanol alone (70%) or in combination with sodium hypochlorite (1%) yielded a relatively higher proportion (≥ 96%) of aseptic culture establishment in both rainy and dry seasons. Explant size affected the survival and regeneration of cultures where small explants (˂ 10 mm) like meristem dome showed relatively slower re-growth and high mortality in contrast to large explants (≥ 10 mm). Moreover, culturing in BAP-supplemented Murashige and Skoog medium (MS) significantly enhanced the greening/shoot regeneration percentage at 14 d. However, there was no significant increase in number of green shoots/culture regeneration at BAP concentrations of 5 mg/l, 6 mg/l, and 8 mg/l for Nshakara and 3 mg/l, 5 mg/l, and 6 mg/l for Mzuzu. Browning decreased by 18% when explants were pre-treated with 100 mg/l ascorbic acid for 10 min. Further, growth conditions such as light were a relatively greater determinant for regeneration of initiated banana cultures. Therefore, our findings suggest the use of appropriate sterilization techniques, explant size, growth regulators, and conditions to ensure sufficient production of planting materials.