Monitoring of Fusarium circinatum spore loads in South African forest seedling nurseries
This project focussed on the pine pathogen Fusarium circinatum as this fungus is responsible for great economic losses and endangering pine forests worldwide. A better understanding of this pathogen could lead to improved disease management, thus limiting the dispersal of the fungus. A diagnostic...
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2013
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| Online Access: | http://hdl.handle.net/2263/31283 De Wet, L 2011, Monitoring of Fusarium circinatum spore loads in South African forest seedling nurseries, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/31283 > http://upetd.up.ac.za/thesis/available/etd-09232011-091323/ |
| Summary: | This project focussed on the pine pathogen Fusarium circinatum as this fungus is responsible
for great economic losses and endangering pine forests worldwide. A better understanding of
this pathogen could lead to improved disease management, thus limiting the dispersal of the
fungus. A diagnostic technique, whether non-DNA-based or DNA-based, should be chosen
with care to ensure obtaining accurate results, limiting expenses and time needed to complete
a project. This study reviewed the techniques used for the identification and detection of
Fusarium species. Non-DNA-based and DNA-based techniques focus on the morphological
or chemical traits, and nucleotide sequence respectively. This review enabled the selection of
an appropriate detection and quantification technique for F. circinatum, as the advantages and
disadvantages of all techniques were considered and compared.
The intergenic spacer (IGS) region of the ribosomal RNA repeat module is a popular
diagnostic marker for Fusarium species due to the region’s multiple copies in the genome and
fast evolution rate. This marker was evaluated to determine if it could be used for F.
circinatum diagnostics. The results confirmed the IGS region to be a good diagnostic marker,
due to the region’s species specificity, by comparing the IGS region of F. circinatum and
other G. fujikuroi complex species. The results of phylogenetic analysis of all the isolates
included in this study were supported by those of previous studies that also focussed on the
IGS region.
Real-time PCR was used successfully for the detection and quantification of F. circinatum
during past studies. Due to these successes, real-time PCR was chosen as the technique for
the quantification of F. circinatum spores in a pine seedling nursery. The results of this study
showed that the real-time PCR technique employed was specific and sensitive as it allowed
detection of low spore concentrations. The study also showed that there is a correlation
between spore production and temperature and that spore dispersal is possibly, but not
exclusively, due to air movement. Real-time PCR can thus be used for future studies that
focus on the detection and quantification of F. circinatum as this study has shown this
technique to be effective. === Dissertation (MSc)--University of Pretoria, 2011. === Microbiology and Plant Pathology === Unrestricted |
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