Pre-selection of banana somaclones resistant to Fusarium oxysporum f. sp. cubense, subtropical race 4

Tamyres Amorim Rebouças; Anelita de Jesus Rocha; Tamires Sousa Cerqueira; Poliana Ramalho Adorno; Rafael Queiroz Barreto; Mileide Dos Santos Ferreira; Lucymeire Souza Morais Lino; Vanusia Batista de Oliveira Amorim; Janay Almeida Dos Santos-Serejo; Fernando Haddad; Claudia Fortes Ferreira; Edson Perito Amorim

doi:10.1016/j.cropro.2021.105692

Pre-selection of banana somaclones resistant to Fusarium oxysporum f. sp. cubense, subtropical race 4

Crop Prot. 2021 Sep:147:105692. doi: 10.1016/j.cropro.2021.105692.

Affiliations

¹ Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brazil.
² Universidade Federal do Recôncavo da Bahia, Cruz das Almas, Bahia, Brazil.
³ Embrapa Mandioca e Fruticultura, Rua Embrapa, s/n CP 007, Chapadinha, Cruz das Almas, Bahia, Brazil.

Abstract

- Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases affecting banana crops worldwide. Therefore, the development of resistant cultivars is a promising alternative to mitigate the effects of the disease on banana plantations. The objectives of this study were to induce somaclonal variation in banana cultivars of the Silk and Cavendish types and to select somaclones resistant to subtropical race 4, thereby enabling the production of fruit in areas where this race is present. Shoot clump apexes of the Grand Naine and Maçã (Silk) cultivars were grown in MS medium. The cultures were subcultured four times. They were then challenged with fusaric acid (FA) in an experiment consisting of four treatments with different concentrations (0.1, 0.2, 0.3, and 0.4 mM) and five repetitions, each consisting of a Petri dish containing seven multiple shoot clumps in MS culture medium supplemented with 2.5 mg/L benzylamine purine. Multiple shoot clumps without the addition of FA were also used in the experiment, and were subcultured three times and maintained in a dark room. The multiple shoot clumps that survived the treatment with FA were transferred to MS medium and maintained in the growth chamber in the presence of light. The regenerated plants were later planted in tanks containing soil infested with an isolate classified as Foc subtropical race 4 (Foc STR4), and were evaluated for resistance to the pathogen at 90 days after inoculation (d.a.i.). Pathogen structures were confirmed by root clarification and root staining technique. All somaclones of the Maçã (Silk) cultivar were susceptible to Fusarium wilt and two somaclones of the Grand Naine cultivar were selected as resistant. The addition of FA as a selective agent was effective in the selection of somaclones among plants of the Grand Naine cultivar, as shown by the selection of two somaclones resistant to Foc STR4. The next step will consist of the agronomic and market potential validation of the selected somaclones, aiming to confirm their potential use by producers.

Keywords: Genetic improvement; Musa species; Plant health; Somaclonal variation.