Ms Ariska Van Der Nest
Biochemistry, Genetics and Microbiology
My PhD project focuses on the diversity and invasion biology of two important pine needle pathogen genera, Dothistroma and Lecanosticta.
Lecanosticta acicola is the causal agent of brown spot needle blight of pines. This disease affects pine seedlings as well as young trees and causes premature defoliation that leads to stunted growth and in severe cases mortality of the trees. It is currently listed as an A2 quarantine pathogen in several European countries and evidence suggests that the pathogen was introduced from North America into Europe on two different occasions. As the origin of this species is still unknown and previous studies suggests that Central America could be the origin, one aspect of my project focuses on investigating the diversity of Lecanosticta in this region further.
Dothistroma needle blight is caused by two morphologically indistinguishable species, Dothistroma pini and D. septosporum. D. septosporum has a worldwide occurrence while D. pini has only been recorded in the Northern hemisphere. Although population studies have been done to understand the movement of the pathogens (especially D. septosporum), little is known about the co-occurrence of these species and the movement between native and non-native Pinus species. This aspect will also be further investigated in this study.
Presentations and Posters
van der Nest, A., Wingfield, M.J., Barnes, I. 2018. The rising threat of novel pine needle pathogens from Central America under expanding global cultivation. 44th Conference of the South African Association of Botanists, 9-12 January 2018, Pretoria, South Africa. p91.
Barnes, I., van der Nest, A., Ortiz, P., Wingfield, M. 2017. New cryptic species and a putative center of diversity for the pine pathogens Dothistroma and Lecanosticta. IUFRO 125th Anniversary Congress, 18-22 September 2017, Freiburg, Germany. p221.
van der Nest, A., Wingfield, M.J., Barnes, I. 2017. Diversity of Lecanosticta species in Central America suggests a centre of diversity for an important group of pine needle pathogens. 50th Anniversary Congress of the Southern African Society for Plant Pathology, 15-18 January 2017, Champagne Sports Resort, Drakensberg. Poster 26.
van der Nest, A., Wingfield, M.J., Barnes, I. 2016. The phylogenetic diversity of Lecanosticta in Central America suggests a centre of diversity for this genus. 4th Joint congress of the SA Society for Bioinformatics and the SA Genetics Society, 20-23 September 2016, Durban, South Africa. p35
van der Nest, A., E.T. Steenkamp & G.J. Marais. 2009. Phylogenetic relatedness of Phoma sorghina as a mycotoxigenic fungus in South Africa. International Society for Mycotoxicology conference, 9-11 September 2009, Tullin, Austria.
van der Nest, A., Steenkamp, E.T., Marais, G.J. 2009. Phylogenetic definition of Phoma sorghina based on the ITS, EF-1α and β-tubulin gene regions. 46th Congress of the Southern African Society for Plant Pathology and 6th Congress of the African Mycological Association (AMA), 25 – 28 January 2009, Villa Via Hotel, Gordon’s Bay, South Africa. p110.
van der Nest, A., Steenkamp, E.T., Marais, G.J. 2008. Phylogenetic diversity of Phoma sorghina in Southern Africa. Biennial Conference of the South African Society for Microbiology (Bio-08), Rhodes University, 21-25 January 2008. p 40.
van der Nest, A., Steenkamp, E.T., Marais, G.J. 2008. Phylogenetic variation within Phoma sorghina sensu lato. 20th Biennial congress of the South African Genetics Society, h Biennial congress of the South African Genetics Society, Sanlam Auditorium, University of Pretoria, 27 – 29 March 2008. p 81.
van der Nest, A., Steenkamp, E.T., Marais, G.J. 2007. Phoma sorghina: a review on the complexity of its taxonomy and ecological distribution. Abstracts of the 45th Congress of the South African Society for Plant Pathology, Kopanong, 21 – 24 January 2007. p53.
van der Nest, A., Marais, G.J., Lübben, A. 2006. The role of mycotoxigenic fungi in commercially produced animal feed. Abstracts of the 14th Biennial Conference of the South African Society for Microbiology, CSIR International Convention Centre, 9-12 April 2006. p130.
van der Nest, A., Marais, G.J., Lübben, A. 2006. Fungi and their mycotoxins associated with animal feed in South Africa. Abstracts of the 44th Congress of the South African Society for Plant Pathology, Magalies Park Country Club, 22-25 January 2006. p74.