Clonal population structure of the chestnut blight fungus in expanding ranges in southeastern Europe
Articolo
Data di Pubblicazione:
2008
Citazione:
Clonal population structure of the chestnut blight fungus in expanding ranges in southeastern Europe / M.G. Milgroom, K. Sotirovski, D. Spica, J.E. Davis, M.T. Brewer, M. Milev, P. Cortesi. - In: MOLECULAR ECOLOGY. - ISSN 0962-1083. - 17:20(2008 Aug), pp. 4446-4458.
Abstract:
Expanding populations are often less genetically diverse at their margins than at the centre
of a species’ range. Established, older populations of the chestnut blight fungus, Cryphonectria
parasitica, are more variable for vegetative compatibility (vc) types than in expanding
populations in southeastern Europe where C. parasitica has colonized relatively recently.
To test whether vc types represent clones, we genotyped 373 isolates of C. parasitica
from southern Italy, Romania, Bulgaria, Macedonia, Greece and Turkey using 11 sequencecharacterized
amplified region (SCAR) markers. Ten SCAR loci and six vegetative incompatibility
(vic) loci were polymorphic in these samples. These populations are clonal by all
criteria tested: (i) among 373 isolates, we found only eight multilocus haplotypes, and the
same haplotypes were found in multiple countries, sometimes separated in time by as
much as 12 years; (ii) the number of haplotypes observed was significantly less than
expected under random mating; (iii) populations are in linkage disequilibrium; (iv) the two
sets of independent markers, SCARs and vc types, are highly correlated; and (v) sexual
structures of C. parasitica were found only in Bulgaria and Romania. One mating type
(MAT-1) was found in 98% of the isolates sampled. In contrast, a population in northern
Italy, in the central part of the range in Europe, had 12 multilocus haplotypes among 19 isolates.
The spread of a few clones could be the result either of founder effect and restricted migration,
or these clones have greater fitness than others and spread because they are better adapted
to conditions in southeastern Europe.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
chestnut blight fungus ; clonal population ; Cryphonectria parasitica ; marginal populations ; population structure ; SCARs
Elenco autori:
M.G. Milgroom, K. Sotirovski, D. Spica, J.E. Davis, M.T. Brewer, M. Milev, P. Cortesi
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