Mutant plantains (Musa spp.) with height reduction obtained by in vitro mutagenesis

Use of biotechnology techniques combined with mutagenesis in Musa spp. allows genetic variability to be increased to improve important agronomic characters. Damage caused to Musa plantations by strong winds and tropical hurricanes makes it necessary to select clones with reduced height and better resistance to wind. The objective of this study is to develop mutant clones of FHIA-21 (Musa AAAB) with reduced height, a good agronomical trait. Multiple buds obtained by in vitro culture were subjected to gamma radiation from ⁶⁰Co sources at dose of 25 Gy. Irradiated buds were multiplied, elongated, rooted, and then planted (10,000 plants) in the field. In the clonal study, 98 mutant clones with lower pseudostem height compared with the original cultivar were selected. Four mutants with reduced height at bunch emergency were selected (IBP 14-23, IBP 17-13, IBP 24-14, and IBP 47-4). Mutants IBP 24-14 and IBP 47-4 showed poor agronomical features, reduced foliar area, and resulted of no commercial value. The results indicated that mutant IBP 14-23 retains the character of resistance to black sigatoka from its parent FHIA-21, combined with important agronomical traits during the third culture cycle, making it a promising cultivar material, representing 0.01% selection efficiency. This is the first report of improvement for height reduction of the tetraploid hybrid FHIA-21 through physical mutagenesis.