Population genetic structure of Rhizoctonia solani AG 3-PT from potatoes in South Africa.
Rhizoctonia solani AG 3-PT is an important potato pathogen causing significant yield and quality losses in potato production. However, little is known about the levels of genetic diversity and structure of this pathogen in South Africa. A total of 114 R. solani AG 3-PT isolates collected from four geographic regions were analysed for genetic diversity and structure using eight microsatellite loci. Microsatellite analysis found high intra-population genetic diversity, population differentiation and evidence of recombination. A total of 78 multilocus genotypes were identified with few shared among populations. Low levels of clonality (13-39 %) and high levels of population differentiation were observed among populations. Most of the loci were in Hardy-Weinberg equilibrium and all four populations showed evidence of a mixed reproductive mode of both clonality and recombination. The PCoA clustering method revealed genetically distinct geographic populations of R. solani AG 3-PT in South Africa. This study showed that populations of R. solani AG 3-PT in South Africa are genetically differentiated and disease management strategies should be applied accordingly. This is the first study of the population genetics of R. solani AG 3-PT in South Africa and results may help to develop knowledge-based disease management strategies.
Department of Plant Science, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa; Tobacco Research Board, Zimbabwe.
Norman
N
Muzhinji
Department of Plant, Soil and Entomological Sciences, Parma Research and Extension Center, University of Idaho, Parma, ID 83660, USA.
James W
JW
Woodhall
Agricultural Research Council, Private Bag X134, Queenswood 0121, South Africa.
Mariette
M
Truter
Department of Plant Science, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa. Electronic address: Jacquie.vanderwaals@up.ac.za.
Jacquie E
JE
van der Waals
D004271:DNA, Fungal / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D018895:Microsatellite Repeats; D011995:Recombination, Genetic; D012232:Rhizoctonia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D011198:Solanum tuberosum / Q000382:microbiology*; D013019:South Africa
D004271:DNA, Fungal
Genetic diversity; Microsatellite; Population structure; Recombination