The inheritance of mitochondrial DNA (mtDNA) in sexual crosses was inv
estigated to expand our understanding of the large genetic divergence
in mtDNAs among natural populations of the higher basidiomycete Pleuro
tus ostreatus. Reciprocal crosses were made between compatible monokar
yons with distinguishable mtDNA restriction fragment length polymorphi
sms (PFLPs). Almost all of the dikaryons produced by these crosses had
mtDNA genotypes from one of the parental monokaryons. However, for di
karyons isolated from the junction-zone of crossed monokaryons, recomb
inant mitochondrial genomes commonly appeared. These results showed th
at P, ostreatus mtDNA can be inherited biparentally, via mtDNA recombi
nation, as well as uniparentally. Further, it was suggested that mtDNA
recombination may be an important source of variation in mitochondria
l genomes among natural populations of P. ostreatus.