Banana is a staple food in many developing countries and an important export commodity for numerous farmers in the tropics. Several diseases threaten world banana production causing signifi cant yield losses every year and, among these, fungal diseases are of major concern. The foliar fungal disease black Sigatoka, the causal agent of which is the airborne fungus Mycosphaerella fi jiensis, is considered the most economically important leaf disease of banana (Churchill 2010). For example, in southern Mexico and throughout Central America it has been estimated that the cost of pesticide sprays to control M. fi jiensis accounts for up to 30% of production costs (Agrios 2005). The intensive fungicide applications are not only expensive for many farmers but also represent a serious health risk to plantation workers and threaten the environment. Another devastating fungal disease is Panama disease caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC). FOC race 1 wiped out the banana industry in the 1950s, when this industry was based on the cultivar “Gros Michel”. Now a new race of this pathogen, FOC race 4, has emerged as a serious threat to the current commercial banana cultivars of the Cavendish subgroup, which are resistant to FOC race 1 but susceptible to FOC race 4 (Ploetz and Pegg 2000; Ploetz 2005). Sources of resistance have been found in wild bananas for these two fungal diseases, however the molecular nature of the resistance is currently unknown. Therefore, knowledge about the genes involved in disease resistance in banana is crucial for the genetic improvement and sustainable production of this crop.