Molecular Ecology (2012) 21, 4452-4471

Guillermo Pérez, Bernard Slippers, Michael J. Wingfield, Brenda D. Wingfield, Angus J. Carnegie and Treena I. Burgess (2012)
Cryptic species, native populations and biological invasions by a eucalypt forest pathogen
Molecular Ecology 21 (18), 4452-4471
Abstract: Human-associated introduction of pathogens and consequent invasions is very evident in areas where no related organisms existed before. In areas where related but distinct populations or closely related cryptic species already exist, the invasion process is much harder to unravel. In this study, the population structure of the Eucalyptus leaf pathogen Teratosphaeria nubilosa was studied within its native range in Australia, including both commercial plantations and native forests. A collection of 521 isolates from across its distribution was characterized using eight microsatellite loci, resulting in 112 multilocus haplotypes (MLHs). Multivariate and Bayesian analyses of the population conducted in structure revealed three genetically isolated groups (A, B and C), with no evidence for recombination or hybridization among groups, even when they co-occur in the same plantation. DNA sequence data of the ITS (n = 32), β-tubulin (n = 32) and 27 anonymous loci (n = 16) were consistent with microsatellite data in suggesting that T. nubilosa should be considered as a species complex. Patterns of genetic diversity provided evidence of biological invasions by the pathogen within Australia in the states of Western Australia and New South Wales and helped unravel the pattern of invasion beyond Australia into New Zealand, Brazil and Uruguay. No significant genetic differences in pathogen populations collected in native forests and commercial plantations were observed. This emphasizes the importance of sanitation in the acquisition of nursery stock for the establishment of commercial plantations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Treena Burgess, Bernard Slippers, Michael J. Wingfield, Brenda D. Wingfield, Angus J. Carnegie

Research topic(s) for pests/diseases/weeds:
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Teratosphaeria nubilosa	Eucalypt (Eucalyptus)	Australia (South+SE)
	Teratosphaeria nubilosa	Eucalypt (Eucalyptus)	New Zealand
	Teratosphaeria nubilosa	Eucalypt (Eucalyptus)	Uruguay
	Teratosphaeria nubilosa	Eucalypt (Eucalyptus)	Australia (Western)