Molecular Characterization of Fusarium Oxysporum F. Sp. Cubense of Banana

Problem statement: Morphological characterization of Fusarium species which emphasize on microscopic and cultural characteristics are not sufficient to characterize Fusarium Oxysporum F. sp. Cubense (FOC) from banana as these characteristics could easily influence by environmental factors. As an alternative molecular methods were used to characterize and to assess genetic variation of FOC from different banana cultivars. Knowledge on the genetic variation is important to determine the genetic relationship between FOC isolates from different banana cultivars. Approach: Two PCR-based methods, Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) and restriction analysis of the Internal Transcribed Spacer and 5.8S regions (ITS+5.8S regions) were used to characterize Fusarium Oxysporum F. sp. Cubense (FOC) isolates from different banana cultivars. The genetic relationship of the FOC isolates were analyzed using Un-weighted Pair-Group Method with Arithmetic Averages (UPGMA) cluster analysis based on Jaccard Similarity Coefficient. Results: Restriction patterns of the ITS+5.8S regions using nine restriction enzymes namely, Alu I, Eco RI, Eco 88I, Bsu RI, Bsu 15I, Hin fI, Hin 6I, Msp I and Taq I and ERIC-PCR showed low variation among the FOC isolates studied, indicating close relationship among the isolates. Un-weighted Pair-group Method with Arithmetic Averages (UPGMA) cluster analysis based on Jaccard Similarity Coefficient showed that the FOC isolates were grouped into two main clusters with similarity value of 41.4-100% in PCR-RFLP of ITS + 5.8S and 45-100% similarity based on ERIC-PCR analysis, respectively. Cluster analysis of the combined data also showed that the FOC isolates were grouped into two clusters, sharing 42.9-100% similarity. Conclusion/Recommendations: The results of the present study indicate that the FOC isolates were closely related regardless of banana cultivars and location.