CONSTRUCTION OF PHYSICAL MAPS OF MITOCHONDRIAL DNAS IN FUSARIUM SPECIES CAUSING FUSARIUM HEAD BLIGHT

RFLPs in Mitochondrial (mt) DNAs were analyzed using 21 strains from s even Fusarium species that cause fusarium head blight in wheat, includ ing F. graminearum, F. culmorum, F. avenaceum, F. acuminatum, F. sporo trichioides, F. nivale, and F. tricinctum. MtDNA was purified by CsCl ultracentrifugation in the presence of bisbenzimide. Molecular sizes o f mtDNAs were determined after digestion with restriction enzymes. A l arge interspecific variation was observed in mtDNA size: the largest o ne was 116 Kb in strain ARC-2125-1 of F. culmorum, while the smallest one was 49 kb in strain SUF-1121 off. avenaceum. A considerable intras pecific size variation was also detected. All the species were identif ied by their mtDNA restriction patterns and assigned to individual clu sters by UPGMA analysis, except for one strain of F. sporotrichioides. A PstI clone library was constructed from strain KU-1615 of F. gramin earum that is highly pathogenic and produces a large amount of nivalen ol. Using this library, physical maps of F. graminearum and F. culmoru m were constructed. The mtDNA library and physical maps would facilita te species identification and further study of mtDNA polymorphisms in Fusarium species.