Abstract
Shoot apices of in vitro-grown cultures of banana (Musa spp., AAA Group cv. Highgate) were treated with various concentrations of the mutagens sodium azide, diethyl sulphate, and ethyl methanesulphonate to evaluate their effectiveness in inducing mutations and also with the aim of producing variants tolerant to the fungus Fusarium oxysporum f. sp. cubense. This fungus causes fusarial wilt or Panama disease in banana and plantain. Based on phenotypic variations in regenerated plants, factors of effectiveness were calculated for each treatment. There were no significant differences between the number of variations induced by the mutagens and between different mutagen treatment durations. Regenerated plants were screened for tolerance to the fungus under greenhouse conditions. Twelve weeks after inoculation, 4.6, 1.9 and 6.1% of plants regenerated after sodium azide, diethyl sulphate and ethyl methanesulphonate mutagenesis respectively had less than 10% vascular invasion of their corms with no external symptoms of the disease. These plants were considered to be tolerant and were multiplied, ex vitro, for field screening.