GENETIC DIVERSITY OF FUSARIUM VERTICILLIOIDES ISOLATES FROM MAIZE IN IRAN BASED ON VEGETATIVE COMPATIBILITY GROUPING
A. Mirzadi Gohari, M. Javan-Nikkhah, G.A. Hedjaroude, M. Abbasi, V. Rahjoo, N. Sedaghat
Genetic diversity among Fusarium verticillioides isolates was analyzed using vegetative compatibility groups (VCGs). Forty-four isolates of F. verticilliodes from stalks and seeds were recovered in maize-producing areas in Iran during 2004-2005. Chlorate-resistant nitrate non-utilizing (nit) mutants were recovered from selected isolates of F. verticillioides and used in complementation (heterokaryon) tests. Vegetative compatibility tests by pairing nit mutants identified 25 VCGs among 44 isolates. Twenty-one isolates belonged to single-member VCGs and the remaining 23 isolates belonged to four multimember VCGs. VCG1 was the largest group and included 17 isolates, whereas the other three multimember VCGs contained two isolates each. It is concluded that natural populations of F. verticillioides in Iran are genetically highly divergent and include isolates representing a potential risk for disease development.