Biotechnological tools for the development of Foc TR4-resistant or-tolerant musa spp. cultivars

Abstract

Bananas and plantains (Musa spp.) are one of the commercially important tropical fruit crops in the world. Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most damaging diseases affecting Musa worldwide. The banana export industry based on the 'Gros Michel' (Musa AAA) cultivar in Latin America and the commercial production of the 'Manzano' (Musa AAB) cultivar in Cuba were decimated during the Foc race 1 outbreak in the twentieth century. Currently, the Foc tropical race 4 (TR4) has caused serious damage to the export standards for the Cavendish subgroup in Southeast Asia and continues to spread among banana-producing countries. Around 80% of banana cultivars produced worldwide are susceptible to this race, which represents an imminent threat for producing countries of Latin America and the Caribbean where the pathogen has not yet been detected. Biotechnological tools offer the opportunity to obtain resistant or tolerant cultivars to Foc through the combination of somatic embryogenesis and breeding techniques. In vitro mutagenesis using gamma radiations with a 60Co source alongside Agrobacterium tumefaciens-mediated genetic transformation with anti-fungal genes will provide mutant and transgenic lines for early screening under various conditions. Tissue culture facilitates the rapid cloning of variants selected from greenhouse and field conditions. In addition, the use of antagonistic bacteria and fungi for the management of the pathogen can increase the resistance level of the new cultivars. In particular, the selection and study of the mechanisms of action of native microorganisms with antagonistic properties against Foc, such as Bacillus and Trichoderma, may contribute to the management of the disease.