6 Wood Discoloration

44 2 Biology
Table 2.9. Species-specific ITS-PCR primers (reverse) with target area (bp) in the ITS II if the
ITS 1 primer of White et al. (1990) is used as forward primer (complemented from Moreth
and Schmidt 2000)
Species Specific primer (5 ′ → 3 ′ ) Target
area (bp)
Serpula lacrymans ATG TTT CTT GCG ACA ACG AC 567–587
CAG AGG AGC CGA TGA ACA AG 459–478
Serpula himantioides TCC CAC AAC CGA AAC AAA TC 410–429
Coniophora puteana AGT AGC AAG TAA GGC ATA GA 614–633
Antrodia vaillantii CAC CGA TAA GCC GAC TCA TT 498–517
ACT GAC TAC AAA ATG GCG CG 445–464
Oligoporus placenta TTA CAA GCC AGC ATA AAC CT 431–450
Donkioporia expansa TCG CCA AAA CGC TTC ACG GT 525–544
Gloeophyllum sepiarium GTT AAT AAA AAC CGG GTG AG 379–398
Fig.2.23. Electrophoresis gel demonstrating species-specific priming PCR. L–A codes of
specific primers which detected isolates of Serpula lacrymans (L), S. himantioides (H),
Coniophora puteana (C), Donkioporia expansa (D), andAntrodia vaillantii (A). M marker
(200–900 bp) (from Moreth and Schmidt 2000)
closely related annulate European Armillaria species A. borealis, A. cepistipes,
A. gallica, and A. ostoyae, exhibited rather similar ITS sequences and also
intraspecific variation, that is a specific primer was only obtained for A. mellea
(Potyralska et al. 2002; also Chillali et al. 1998). In addition, intraspecific
variation may also occur with regard to the geographic origin of isolates
(Kauserud et al. 2004b). The main limitation is, however, comparable to ITS-
RFLPs, that the limited ITS size of only 600–700 nucleotides prevents the design
of a specific primer for all relevant fungi of a certain biotope. In a practical
view, also the technical effort becomes big on that score that a great number of
specific primer has to be used for the diagnosis of an unknown sample.
Microsatellites
Microsatellites or simple sequence repeats (SSR) are hypervariable genomic
regions characterized by short tandem repeat sequences of up to seven nu-
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