Restriction fragment length polymorphisms in mitochondrial DNAs of Armillaria: identification of North American biological species

Mitochondrial DNA (mtDNA) restriction fragment patterns of 23 isolates from eight North American biological species of Armillaria were compared. Whole-cell or mtDNAs were digested separately with Eco RI, Bam HI and Hin dIII and probed with either mtDNA or cloned fragments of mtDNA in Southern hybridizations. Cluster analysis (UPGMA, Unweighted Pair-Group Method using Arithmetic means) indicated that mtDNA fragment patterns were similar among isolates of the same, and dissimilar among isolates of different, biological species. Furthermore, analysis of mtDNA fragment patterns allowed correct identification of the biological species to which each of the 23 isolates in the sample belonged. Although mtDNA fragment patterns were very similar within biological species, each isolate had a unique overall pattern. Because of the dissimilarity of mtDNA fragment patterns between biological species, other approaches are needed to resolve phylogenetic relationships within Armillaria