Review on Broken-down Resistance to Diseases and Its Management; the Hidden Challenge in Breeding and Production of Banana and Plantains in Developing Countries

Abstract

Resistant breakdown is the genetic vulnerability that is devastating agriculture breeding and production of banana worldwide, therefore threateningburgeoning population.It takes 15 to 20 years for banana breeding pipeline and other stakeholders to release a cultivar that is fully evaluated to farmers. Disease like fusarium wilt disease (race 1) was reported to wipe away Gros Michel and the Tropical Race 4 (TR4) has wiped away all cultivars which were resistant to race1. Again banana breeding for resistant to sigatoka successively bred and released many hybrids but of recently of these hybrids including FHIA hybrids, Yagambi KM 5, Paka, young Calcutta 4 and T8 has lost their resistant to sigatoka. Due to political and commercial pressures, it is true that most of the released resistant cultivars are from single effective genes. Though durable resistance with a single dominant gene has been a serious challenge to achieve in breeding, this is because of broken-down resistance. This review used online resource to identify some causes of broken resistance in banana and provided some possible solutions to increase durability. Causes of broken resistance includes the practice of monoculture in large area, illegal use of chemicals, multiple infections, evolution of pathogens as the result of recombination, mutations, nature of interaction exhibited by released cultivars, low genetic base in banana, gene flow, through introductions of pathogens and climate change. It is widely accepted that different agronomic practices combined with strategic breeding and release of cultivars can elongate durability of resistant cultivars to pathogens in agricultural system. Through all the literature searched it is being unveiled yet the factors that govern quality and durability of resistance in resistant cultivars. I hereby conclude that breeding for resistance to diseases in banana should go par pursue with other disease management strategies. This is aimed at increasing durability of resistance to diseases in this highly expensive produced banana and plantain hybrids.