Resistência de novo genótipo de bananeira maçã ao Fusarium oxysporum f. sp. cubense e caracterização morfofilogenética do fungo

Abstract

The Brazil produces more than 20 fruits with economic and social importance. Some have high expression on regional markets and others in national and international, among these the banana is the most consumed in Brazil being very requested in foreing market. The Fusarium wilt is a fungical disease caused by Fusarium oxysporum f. sp. cubense (Foc). The pathogen commits the crop productivity and its control is dificulted because the pathogen survival capacity on soil. The “apple” cultivar is highly susceptible to Fusarium wilt, however, in 1990, a new genotype of banana “apple” emerged in Goiás region, supposedly resistant to Fusarium wilt in which has been widely used by the region producers. Because a lack of cientific evidence about the cultivar resistance the Universidade Federal de Lavras (UFLA) and the Empresa de Assistência Técnica e Extensão Rural de Goiás (Emater-Goiás) signed partnership to make studies with this genotipe aiming evidence its resistance. In this way, aimed with this essay evaluate the resistance of the new genotype of banana “apple” to Fusarium wilt and identify using morfological and molecular characters fungi isolates. The first essay was based on the isolation, phylogenetic indentification and agressiveness tests of strains of Foc from three brazilian states. This essay resulted on obtainment of four isolated, all belonging to Fusarium oxysporum f. sp. cubense specie, race 1, with different agressiveness levels and belonging to two diferente lineages. In the second essay, the resistance of the new genotype was evaluated in comparison with others varieties of banana and the traditional banana “apple”, to this, a strain of Foc previously identify by the molecular and morphological methods and that showed high agressiveness was used. The result showed that the new cultivar is moderately resistante to pathogen.