Occurrence of unilateral genetic transfer and genomic replacement between strains of Stereum hirsutum from non-outcrossing and outcrossing populations

Autor: S. J. Broxholme, A.M. Ainsworth, Alan D. M. Rayner, John R. Beeching
Rok vydání: 1990
Předmět:
Zdroj: New Phytologist. 115:119-128
ISSN: 1469-8137
0028-646X
DOI: 10.1111/j.1469-8137.1990.tb00929.x
Popis: SUMMARY Populations of the wood-decaying basidiomycete, Stereum hirsutum (Willd. ex Fr.) S. F. Gray, from different geographical regions, reproduce either by outcrossing or non-outcrossing. Outcrossing generates variable progeny whilst non-outcrossing results in clonal sub-populations. Pairings between single-basidiospore-derived strains from non-outcrossing and outcrossing populations commonly result in mutual rejection or mycelial invasion of the outcrosser by the non-outcrosser. However, on the basis of both morphological evidence and studies of DNA restriction fragment length polymorphisms, some pairings result in unilateral transfer of nuclear DNA from the non-outcrosser into the outcrosser. In some combinations the resultant putative heterokaryon may be stable and give rise to variable basidiospore progeny with unusual development and non-self recognition responses and at least one mating-type specificity evidently transferred from the non-outcrosser. In other, combinations, genomic takeover by the non-outcrosser has been demonstrated, leading respectively to the emergence of mycelial sectors or production of basidiospore progeny in which solely or predominantly non-outcrossing nuclear DNA is associated with outcrossing mitochondrial DNA. These observations add a new perspective to the selective pressures influencing sexual outcrossing and nonoutcrossing and the role and interplay of these breeding strategies in reproductive isolation and speciation.
Databáze: OpenAIRE
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