MITOCHONDRIAL-DNA RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS IN NATURAL-POPULATIONS OF LENTINULA-EDODES

A survey of mitochondrial DNA (mtDNA) restriction fragment length poly morphisms (RFLPs) in 51 wild strains from different geographical popul ations of the basidiomycete Lentinula edodes was carried out to examin e genetic relatedness. Thirty-eight of the 51 strains were from Japan, seven from Papua New Guinea, four from New Zealand, one from Borneo, and one from Thailand. EcoR I or BamH I digests of mtDNAs from these s trains produced 24 and 12 distinct RFLP patterns, respectively. By com bining the RFLP patterns obtained with the two endonucleases, mtDNAs f rom the 51 wild strains of L. edodes could be assigned to 28 different mtDNA phenotypes. A similarity matrix calculated between all pairs of mtDNA phenotypes based on the presence or absence of comigrating rest riction fragments was analysed with UPGMA and Fitch-Margoliash analyse s. Results of both analyses were highly consistent and showed that the mtDNA phenotypes of L. edodes could be divided into five major cluste rs, each of which accommodates a geographically distinct population. T he phylogenetic relationships among the natural populations of L. edod es deduced from the present study were consistent with previous isozym e analyses. This suggests that L. edodes includes some distinct groups with genetic divergence in both mitochondrial and nuclear genomes.