Variation in the mitochondrial DNA of the potential biological control agent Chondrostereum purpureum

The mitochondrial DNA (mtDNA) of Chondrostereum purpureum (Pers.:Fr.) Pouzar was extracted and purified, and the size ranged from 51.8 to 66.4 kb. One isolate each from British Columbia, Alberta, Finland, the Netherlands, and New Zealand were found to have identical BamHI mtDNA restriction patterns, resulting in a mitochondrial genome of 63.8 kb. An additional isolate from British Columbia and one from Switzerland had different banding patterns, however, resulting in mitochondrial genomes of 66.4 kb and 51.8 kb, respectively. A sequence-characterized amplified region (SCAR) assay, based on a polymerase chain reaction, was developed to rapidly screen a larger population of 84 isolates from North America, Europe, and New Zealand. Two SCARs, one encoding the NADH 4 gene (3 kb) and the second encoding the ATPase VI and cytochrome b genes (5.1 kb), were digested with 24 restriction enzymes. There were no polymorphisms in the NADH 4 containing SCAR, while a single polymorphism was detected by NsiI in the ATPase VI - cytochrome b containing SCAR. Two mitochondrial haplotypes that were distributed throughout the sample population were thus identified. The coancestry coefficient (<$Q7A0D00000010446D80BFFEFF88A524F5343905055B98C420120907B4DDA9ECB1F0>) for all subpopulations of the sample population was calculated to be 0.0353. The level of gene diversity in the mtDNA ofC. purpureum suggested that the chance introduction of novel mitochondrial genes following biological control applications of the fungus is relatively low.