Greenhouse pre-screening of banana somaclones derived from the Grand Naine cultivar (Cavendish, AAA) resistant to Fusarium oxysporum f . sp. cubense, subtropical race 4

Abstract

Banana production is affected by several pests and diseases, of which Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is notable. Despite the different control measures and management used to contain Fusarium wilt, the development of resistant cultivars has been the best approach to combating this disease. This study explores a biotechnological approach with the potential to induce somaclonal variation using the plant growth regulators Thidiazuron (TDZ) and paclobutrazol® (PBZ) in the banana cultivar ‘Grand Naine’ (Cavendish, AAA), and proposes a greenhouse pre-screening based on inoculation bioassays with Foc, using the commercial cultivar Grand Naine as a susceptible control. The somaclonal variants showed 3.5% of highly resistant plants, which were immune to Foc inoculation in the first round of tests. Of these, thirteen (43.3%) maintained their resistance response when subjected to a second test in an experiment with replicates. In addition, histological analysis of roots demonstrated the absence of pathogen structures, such as hyphae, conidia, or chlamydospores, within the tissues of these somaclones. This study provides Cavendish somaclones that have never before been generated and pre-selected under greenhouse conditions. These somaclones will be further evaluated for agronomic and market potential, as well as for validation of resistance stability, with the aim of future recommendation to farmers and use in breeding programs.

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