Genetic diversity of Fusarium oxysporum f. sp. cubense isolates from Malaysia

Genetic diversity of Fusarium oxysporum f. sp. cubense (FOC) isolates were analyzed using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR), random amplified microsatellites (RAMS) and restriction fragment length polymorphism of Intergenic Spacer (RFLP-IGS). The three molecular techniques showed intraspecific variations and the banding patterns generated using each technique were highly variable. UPGMA cluster analysis of the combined data of the three techniques showed 35.7 - 100% genetic similarity among the FOC isolates. Based on the dendrogram, most of the isolates including four isolates from Indonesia were clustered together in two main clusters. Sequence analysis of TEF-1α gene of some of the isolates of FOC using parsimony and distance methods also showed intraspecific variations. The highly variable banding patterns shown by using molecular methods supported the hypothesis that the isolates of FOC co-evolved with the edible bananas and dissemination of the pathogen was probably through infected rhizomes.   Key words: Fusarium oxysporum f.sp. cubense, enterobacterial repetitive intergenic consensus PCR, random amplified microsatellites, restriction fragment length polymorphism of Intergenic Spacer.