In Vitro Based Mass-Screening Technique for Early Selection of Banana Mutants Resistant to Fusarium Wilt

Abstract

Banana and plantains are among the most valuable agricultural commodities in the world. Banana Fusarium wilt, caused by the soil-borne Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases of banana globally. In the 1990s a new strain of Fusarium oxysporum called tropical race 4 (TR4) emerged in Southeast Asia that affected commercial Cavendish plantations. The development of resistant cultivars is an effective strategy for management of the disease. Field-based screening to identify Foc-resistant plants is time-consuming, expensive and is often challenged by variable environmental conditions. Here we present an early selection protocol enabling evaluation of the disease under in vitro conditions. This method provides a preliminary screening and allows evaluation of a large number of in vitro plantlets. Using this method, within a short time and in a small laboratory, breeders can evaluate thousands of banana plantlets, produced via irradiation. Subsequently, putative, disease-resistant mutant lines can be identified and evaluated in the field.