Abstract

Soil fungi, Fusarium solani and Fusarium oxysporum f. sp. passiflorae are among the pathogens of greatest economic importance to the passion fruit culture. Little is known about the genetic variability of these pathogens from different regions. The genetic variability of F. solani and F. oxysporum f. sp. passiflorae isolates from Pantanal, Amazon and Cerrado of Mato Grosso State, Brazil, was studied with the help of molecular markers inter-simple sequence repeat amplification (ISSR) and inter-retrotransposon amplified polymorphism (IRAP). The molecular identification of the isolates was performed by partial sequencing of the internal transcribed spacer (ITS) of the rDNA region. High genetic variability among isolates of F. solani and F. oxysporum f. sp. passiflorae was found. The dendrogram generated by UPGMA divided the fungi isolates in two large groups, however, with grouping tendency according to the biome of collection only for F. oxysporum f. sp. passiflorae. There was no significant correlation between geographic distance and genetic similarity for F. oxysporum f. sp. passiflorae and F. solani.

Key words: Collar rot, Fusarium wilt, passionflower, Passiflora edulis, inter-simple sequence repeat amplification (ISSR), inter-retrotransposon amplified polymorphism (IRAP).