Genetic Diversity of Macrophomina phaseolina Populations, the Causal Agent of Sesame Charcoal Rot Using Inter-Simple Sequence Repeat Markers

Macrophomina phaseolina is an important soilborne pathogen causing charcoal rot in many important crop plants including sesame, in Iran. A total of 60 isolates of M. phaseolina were collected from the main sesame producing regions in ten provinces of Iran. The genetic diversity among M. phaseolina populations was estimated using InterSimple Sequence Repeat (ISSR), focusing particularly on geographic differentiation. Five ISSR primers generated 105 discernible DNA bands, of which 85 (77.11%) were polymorphic. The greatest value of variability (PPB: 60.00% H: 0.185 I: 0.284) was estimated for Fars population, whereas the least variability (PPB: 9.52% H: 0.042 I: 0.060) was estimated for Kerman population. Total gene diversity exhibited high levels of variability (HT = 0.186). Analysis of molecular variance indicated a large proportion of genetic variability within populations.