Genetic variability of Fusarium oxysporum f. sp. cubense isolates obtained from banana orchards of the north of Minas Gerais

Banana is one of the most consumed tropical fruits in the world, accounting for approximately 10% of world trade in fruits. Panama disease, caused by Fusarium oxysporum f. sp. cubense is a major disease of banana. RAPD marker have been used for taxonomic studies, analysis of variability of virulence in pathogenic fungi, characterization of races and variability inter and intra-specific populations from different regions. The objective of present study was to evaluate the genetic variability of 36 isolates of F. oxysporum f. sp. cubense using RAPD marker. Thirteen RAPD primers were selected and data analysis was performed using the similarity coefficient of Nei and Li. A total of 178 bands were obtained, of which 167 (93.82%) showed polymorphism at least two isolates and only 11 (6.18%) showed monomorphism, demonstrating the high variability among isolates. The genetic distances ranged from 5.7 to 54.6%, and the average distance of 30.2%. According to cluster analysis (UPGMA) no correlation among isolates were found. The results suggest a high genetic variability among isolates and no correlation between molecular groupings and their geographical origin were observed.