PCR primers for the amplification of mitochondrial small subunit ribosomalDNA of lichen-forming ascomycetes

Four primers for the amplification of mitochondrial DNA of lichen-forming a scomycetes are presented. The primers match the conserved regions U2, U4, a nd U6, respectively, of mitochondrial small subunit (SSU) ribosomal DNA (rD NA). Polymerase chain reaction using different combinations of the primers produced single amplification products from DNA of eight lichen-forming fun gal species but did not amplify DNA of two axenic cultured algal species. T he amplification product obtained from Lobaria pulmonaria was sequenced and the 894-bp sequence was compared with the mitochondrial SSU rDNA sequence of Podospora anserina. The two sequences revealed more than 76% identity in the conserved regions U3 to U5 demonstrating that we amplified mitochondri al DNA. The primers matching U2 and U6 yielded amplification products of 80 0-1000 bp depending on the species examined. The variation observed suggest s that mitochondrial SSU rDNA may be useful for phylogenetic analyses of li chen-forming ascomycetes. (C) 1999 The British Lichen Society.