Three genetic groups of the Eucalyptus stem canker pathogen Teratosphaeria zuluensis introduced into Africa from an unknown source.
The Eucalyptus stem canker pathogen Teratosphaeria zuluensis was discovered in South Africa in 1988 and it has subsequently been found in several other African countries as well as globally. In this study, the population structure, genetic diversity and evolutionary history of T. z uluensis were analysed using microsatellite markers to gain an enhanced understanding of its movement in Africa. Isolates were collected from several sites in Malawi, Mozambique, Uganda and Zambia. Data obtained were compared with those previously published for a South African population. The data obtained from 334 isolates, amplified across eight microsatellite loci, were used for assignment, differentiation and genetic diversity tests. STRUCTURE analyses, θ st and genetic distances revealed the existence of two clusters, one dominated by isolates from South Africa and the other by isolates from the Zambezi basin including Malawi, Mozambique and Zambia. High levels of admixture were found within and among populations, dominated by the Mulanje population in Malawi. Moderate to low genetic diversity of the populations supports the previously held view that the pathogen was introduced into Africa. The clonal nature of the Ugandan population suggests a very recent introduction, most likely from southern Africa.
Department of Plant Production and Soil Science, Forest Science Postgraduate Programme, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa. jolanda.roux@fabi.up.ac.za.
Luke
L
Jimu
Department of Microbiology and Plant Pathology, FABI, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
ShuaiFei
S
Chen
Department of Microbiology and Plant Pathology, FABI, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
Michael J
MJ
Wingfield
Bindura University of Science Education (BUSE), P. Bag 1020, Bindura, Zimbabwe.
Eddie
E
Mwenje
Department of Microbiology and Plant Pathology, FABI, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
Jolanda
J
Roux
D017954:Africa South of the Sahara; D001203:Ascomycota / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D005052:Eucalyptus / Q000382:microbiology*; D056426:Genetic Loci; D014644:Genetic Variation; D005838:Genotype; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D005810:Multigene Family; D010935:Plant Diseases / Q000382:microbiology*; D018547:Plant Stems / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
Admixture; Evolutionary history; Genetic diversity; Multi-locus genotype; Population structure