Abstract

Recent research on the evolution, phylogeography and population genetics of the dry rot fungusSerpula lacrymansis reviewed. The fungus causes severe damage to construction wood in temperate regions worldwide. Multi-locus genetic analyses have shown thatS. lacrymansincludes two cryptic species currently referred to as var.shastensisand var.lacrymans. Both lineages occur naturally in high altitude regions, but var.lacrymanshas also spread from its natural range in Asia, and established itself in indoor environments in temperate regions worldwide. Japan was apparently colonized independently from Europe, North and South America by var.lacrymans. The population found in Australia and New Zealand seems to represent a mixture of the Japanese and the Euro-American lineages. Little genetic variation exists in the founder populations of var.lacrymansworldwide. Due to the introduction of a limited number ofvic(vegetative incompatibility) alleles into the founder populations, genetically different individuals often cannot recognize self from non-self through the vegetative incompatibility response. Moreover, only a low number of MAT (mating) alleles seem to be present in Europe. Genetic analyses of the European and Japanese indoor populations have shown thatS. lacrymansmainly spreads sexuallyviabasidiospores. Surprisingly, an excess of heterozygotes has been observed in the founder populations. This could be due to heterozygote advantage caused by a limited number of MAT alleles. Recent analyses of theS. lacrymansgenome provide new opportunities for further research on the dry rot fungus.

Published in

Fungal Biology Reviews
2012, volume: 26, number: 2–3, pages: 84-93

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