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1 Jaarverslag / Annual Report 2005

University of Pretoria CONTENTS (click on headings for text)

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Annual Report 2005�


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Doserende personeel / Lecturing staff

Prof Cloete TE: DSc(Pret) Prof Korsten L: PhD(Pret) Prof Nel LH: PhD(Pret) Pri Sci Nat – Professor and Head Professor Professor

Dr Pietersen G: PhD Dr Wolfaardt F: PhD Prof Aveling TAS: PhD(Natal) Accociate Professor Snr Lecturer Associate Professor

Prof Venter SN: PhD Prof Coutinho TA: PhD (Natal) Prof Theron J: PhD(Pret) (Pret) Snr – Associate Professor Associate Professor Associate Professor

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Prof Labuschagne N: DSc(Agric) Dr Viljoen A: PhD (UOVS) – Snr Dr Steenkamp E: PhD (Pret) (Pret) Pri Sci Nat – Associate Professor Lecturer Snr Lecturer Miss Markotter W: MSc (Pret) Miss M Thantsha: MSc (Pret) Jnr Lecturer Jnr Lecturer

Technical assistants

Ms van Dyk K: MSc(Pret) Mr Pretorius M: BSc(Hons)(Pret)


Mrs Truter M: MSc(Pret) Mrs Bosch A: Nat. Diploma Support Staff Mrs Madelein Botha (Secretary) Mrs Bettie van Rooyen (Secretary) Mrs Lilian Motale Mr Albert Molefe Industry Funded Staff (Citrus and Subtropical) Ms A Redmond: Technical Assistant Ms T Beart: Technical Assistant Ms D Muller: Administrative assistant Dr L Meyer: Research Assistant Mrs K Zeeman: Technical Assistant Ms C Joubert: Research Assistant Mrs A Lombard: Technical Assistant Mrs R Jacobs: Research Assistant Dr T Regnier: Research Assistant


Back (left to right): L. Swart, A. Szmyd-Potapczuk, A. van der Nest, N. van Zyl, B. Hinze, J. Kehrhahn, A.C. Botha, N.K. Scheepers, J. Moulder, G Ross, L.J. Anderson, C.L. Johnson

Middle: A. van der Merwe, M. Veenendal, C.W. Beukes, B. van der Merwe, M.M. van der Berg, I.C. Lee, M.N.B. Phahladira, O. Makhari, I. du Plooy

Front: H. Geyer, M. Makinta, F.J.J. van der Walt

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MSc-Students

Mr D H F du Plessis Mr J M Pretorius Ms A Swanepoel Ms P A Medronho Ms L Burger Ms M Sorrill Ms H J Roos Mr S Omar Ms H Joubert Ms M Nieuwoudt Mr L T Lekoana Mr M L Coetzee Mr Tsivhandekano Mr P Mashau Ms A Hammerbacher Ms B Nel Ms G Fourie Ms L Botha

Mr S J Verwey Mr J Boshoff Mr R Bagnall Mr T J Tshifaro Ms M Wilmot Ms C Brady Ms L Burke Mr W le Roux Ms H Said Mr N van Blerk Ms M Naidoo Ms K Stewart Mrs J Mavhungu Ms B Porter Ms I Greyling Ms C Brady Ms L Stronkhorst Ms A Belgrove

Ms A Ramaite Mrs R Maluleke Ms I Molobela Ms P Randima Ms P Phasha Ms L Grobler Ms A Willis Ms W Keesenberg Me V Govender Ms A Bouwer Ms D Pavlic Mr M Abdo Ms S Groenewald Ms R van Zyl Ms O Koch Ms N P Phalatsi Mr P Coetzee


PhD-Students

Ms B Steyn Mrs E M du Plessis Mr A Hassen Mr H Baimey Ms S Athman Ms S Capindu Mr A Fourie Mrs E Madoroba Me W du Plooy Me I Paul Me M van Eeden Me E de Jager Mr S B Mekbib Mr C van Ginkel Ms M Visser Ms N v/d Berg Mr J de Graaf Mr S Kappindu

Mrs S September Ms M Nambabi Mr R Kirkpatrick Ms M Said Ms K Surridge Ms M Thantsha Mr J Gumbu Mr S Phophi Me J v/d Waals Mr B Maseko Ms R Jacobs MsT Goszczynska Mr G Weldem Mrs E M du Plessis Mr M Bogale Ms J Weyer Ms W Markotter


1. Prof T E Cloete: Elected as a Senior Fellow of WISA 2. Prof T E Cloete: Finalist NSTF Science and Technology Awards for 2005. Category:

Achievement over a lifetime. 3. Prof T E Cloete: Finalist NSTF Science and Technology Awards for 2005. Category: Capacity

building over the past 10 years. 4. Prof T E Cloete: SA Akademie vir Wetenskap en Kuns. Havenga Prys (Biologie) 5. Prof L Korsten: Uitnemende Presteerder toekenning, UP.

Mr M Pretorius

Maree Pretorius matriculated in Potchefstroom and enrolled for a B.Sc. degree at the University of Pretoria which he completed in 1999. He also completed his B.Sc. (Hons) in the Department of Microbiology and Plant Pathology and is currently finishing his Masters degree. His research focuses on the identification of genes involved in Bacillus cereus biofilm formation. He has recently characterized several biofilm impaired mutants and identified the genes involved. He was appointed as a technical assistant in the department in 2005, and his responsibilities include the presentation of practicals for the third year courses in virology, molecular microbiology and molecular genetics of bacteria.

Prof S N Venter During the period of 19 September - 16 December 2005 I had the opportunity to work at the Laboratorium voor Microbiologie (LMG), University of Ghent, Belgium as part of my sabbatical. This was a follow-up on a visit paid to the same laboratory by Teresa Couthino, a co-investigator of this research project two years ago. My host was Prof Jean Swings and I worked closely with Ilse Cleenwerck, Katrien Engelbeen and Dr Marc Vancanneyt, staff members of the BCCM/LMG bacterial culture collection. The research formed part of the South African/Flemish bilateral scientific and technological cooperation agreement. Supplementary funding for the visit

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was obtained from the National Research Foundation. During the last ten years, plant pathogenic isolates of the genus Pantoea have emerged as a serious pathogen of plantation species and agricultural crops. The specific identity of these pathogens and their relationship to known pathogenic Pantoea species still need to be established. On the basis of an AFLP-system developed by one of my students it became evident that we may be dealing with a number of potentially new species associated with disease of Eucalyptus, maize and onion. The objective of my research at LMG was to study these strains in order to determine their taxonomic position.

The research team at the University of Gent are recognised as experts in the field of bacterial taxonomy and classification and were responsible for the description of most of the known Pantoea species. They are one of the few laboratories in the world where DNA:DNA hybridisation can be performed, a technique essential for the description of new species. The prime focus during my stay was to conduct DNA:DNA hybridizations between selected strains representing the various sub-clusters observed in the AFLP tree. The hybridization method is based on fluorometric measurements and requires large quantities of high quality DNA. During my stay most of my time went into the preparation of DNA form the selected strains which was then followed by performing DNA:DNA hybridizations. The results confirmed that we are dealing with potentially new species but indicated that we need to review the current Pantoea species and unnamed hybridization groups falling within this genus to get clarity on the taxonomic position of our strains. The final review of this genus will now be conducted using a multi-locus sequence analysis (MLSA) approach.

The time spent at the laboratory was very productive and the interactions with LMG staff and student enriching and enjoyable. The non-academic highlights of my visit included being part of the first winter snow, meeting with Sinter Klaas and appreciating Flemish culture and hospitality.

Wanda Markotter

Twice in the past year, from 1 April - 12 May 2005 and from 5 July 2005 – 13 January 2006, I have been conducting my research towards a PhD degree in the USA, at the Centers for Disease Control and Prevention, Atlanta, Georgia. My host at this Institution was Dr. Charles Rupprecht, Chief of the CDC rabies section and Director of the WHO collaborating centre on rabies. Funding for this visit was obtained from various sources including the National research foundation (NRF), University of Pretoria International affairs office and from the host institution (CDC). This study visit followed on previous successful collaborations establish by Prof. Nel (Department of Microbiology and Plant Pathology, UP) where he also visited

this facility on sabbatical leave in 2001 and another student from his research group, Miss. Jacqueline Weyer, also completed part of her PhD study in this facility during 2004/2005 on a CDC scholarship. Dr. Rupprecht, together with two final year veterinary students, visited Prof. Nel’s laboratory in August 2004 in an extension of this existing collaboration and with a view of strengthening the surveys of rabies and rabies related viruses in Africa. My research at this facility focused on the epidemiology and pathogenesis of two African rabies-related viruses: Lagos bat virus and Mokola virus. Lagos bat virus (LBV) belongs to genotype 2 of the Lyssavirus genus in the Rhabdoviridae family and Mokola virus to genotype 3. LBV was recently identified again in South Africa, after no reported cases for thirteen years. Several isolations of Mokola virus were also made

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in South Africa from cats in the last decade also after a long (apparent) absence (25 years). Commercially available rabies vaccines do not protect against LBV and Mokola infection. For further protection strategies, the information on the potential impact on human and animal health is crucial. Previous pathogenesis studies indicated that LBV might be of limited pathogenicity, because mortality in laboratory mice was only observed when they were inoculated intracerebrally and not peripherally. This is in contrast with classical rabies virus (lyssavirus genotype 1) that are highly pathogenic and lethal to mice when inoculated via both routes. The new cases identified of rabies-related viruses in South Africa renewed the interest in these viruses particularly because so little is known about their pathogenicity, epidemiology and their significance in the veterinary and public health sectors. The rabies unit at the CDC is equipped with a facility to handle Mokola virus and Lagos bat virus combined with an experimental animal facility. Trained personnel were available to assist in all parts of this research project and this laboratory is considered the world leader in the field. I have really enjoyed working here and have generated highly publishable data (the next step….). Among others, the comparative pathogenicity of LBV within the lyssavirus genus was elucidated for the first time. Our new data contradict the general dogma that LBV is not pathogenic in mice and by implication, terrestrial animals and humans. In addition ,DNA sequencing data generated indicated that genetic distances between available LBV isolates were greater than intragenotypic distances described for other lyssavirus representatives, indicating great variability between isolates classified as Lagos bat virus due to extended periods of evolution on the African continent. Acknowledgements I would like to thank the NRF, University of Pretoria and the host institution for the financial assistance to make this visit possible. I am also very grateful towards the director of the rabies unit, Dr. Charles Rupprecht, for the expertise assistance and intellectual support provided during my research visit to his facility. I also received excellent assistance and support from all the personnel at the host institution in various parts of this project. Last but not least, thank you to my PhD promoter, Prof. Louis Nel for his support and the arrangement of this opportunity.

1. PROF. E.W. KITAJIMA: University of Sao Paulo, Brazil. December 12 – 15, 2005. 2. DR REBECCA GANLEY: Forest Research, New Zealand 3. ULRICH MARKMANN:, University of, Germany 4. LARS KORSTEDE: University of, Germany 5. LARS NEVELING: University of, Germany 6. MARIUS SCHWERDTFEGER: University of, Germany

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Prof P Ashton, CSIR, Pretoria, Prof H Kasan, Randwater, Prof WOK Grabow, Pretoria, South Africa Johannesburg, South Africa South Africa

Prof T Couthino: The phytopathogenic bacteria research group has a collaborative project on the Genus Pantoea with the Laboratory for Microbiology at the University of Gent, Belgium. This project is jointly funded by the Flemish and South African Governments. Dr. SN Venter completed a sabbatical at the University of Gent from September to December 2005. In November, Professor Coutinho visited the University to discuss progress on the project and planned the research for 2006. Prof TE Cloete: • IWA Executive Committee Meetings, London, February 2005 • IWA Strategic Council Meetings, Maastricht, The Netherlands, April 2005 • IWA Executive Committee Meetings, Singapore, July 2005 • IWA Strategic Council Meeting, Mexico, October, 2005 Dr G Pietersen: • Visit International Potato Center (CIP), Lima, Peru. Attend IX International Plant Virus

Epidemiology Symposium. Lima, Peru 4-7 April, 2005. Prof L Korsten: • Keynote speaker at International Conference on Postharvest Technology and Quality

Management in Arid Tropics at Sultan Qaboos University, Sultanate of Oman. January • Represented South Africa at the Joint Working Group meeting of ISO 22003 in Paris, France to

develop an auditing standard for the new food safety management system of ISO 22000, June

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• The Netherlands, Belgium and Sweden following the citrus export chain as part of the Citrus fruit chain project, partially sponsored by Dole EU, August.

• Peru to do a study of agricultural export potential in Peru sponsored by the World Bank, August.

• Eurepgap congress in Paris, France, sponsored by the DTI and SANAS, October. • FAO training course presented in Tanzania for postharvest technology, sponsored by the FAO,

Ocktober. • Represented South Africa as technical expert for the new food safety management system at

the Joint Working Group meeting of ISO 22003 in Denmark, sponsored by DTI and SABS, December.

• Dr E Steenkamp • Research visit to the Department of Biochemistry, University of Montreal, Montreal, Canada. 15

March 2005 – 25 April 2005. • Fusarium Laboratory Workshop, Kansas State University, Manhattan, Kansas, USA. 26 June –

1 July 2005. Dr A Viljoen • Uganda: Research visit for collaboration on banana weevil and bacterial wilt, and attendance of

the Biotechnology Steering Committee meeting in Kampala. 13-16 February. • Benin: Cotonou for GCP meeting, 21-28 May • France: INIBAP in Montpellier and INRA in Dijon, 1-4 June. • USA: Cornell University, North Carolina State University, APS meeting, 13 July – 4 August • Italy: GCP meeting in Rome, 1-4 October Jacqueline Weyer (PhD student of Prof L H Nel) I was invited to further my research in a collaborative effort of Prof Louis Nel’s laboratory and the Rabies Unit of the Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America. I spent 13 months (August 2004 – September 2005) as a research fellow in these laboratories. During my stay I primarily worked on the development of recombinant rabies vaccines based on the poxvirus system. This formed part of the body of work for my PhD study. In addition I received training regarding several facets of rabies diagnostics and virology at the hand of the experts in this laboratory. Rene Sutherland (MSc student of Dr A Viljoen) USA: Training in plastid transformation at the University of Central Florida, Orlando. 25 July - 12 August Gerda Fourie (MSc Student of Dr A Viljoen) Australia: Collection of Fusarium isolates at QDPI, Brisbane. 6-14 March Tanja Gevers (MSc Student of Dr A Viljoen) USA: Training in site-directed mutagenesis at Cornell University, New York. 13 July – 4 August Joanne Fouche (PhD Student of Dr A Viljoen) Uganda: Visit NARO research on bacterial wilt. 13 – 16 February, 17 – 22 April


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Innovative applied research in water resource management Unsafe drinking water places tremendous stress on the health and lives of millions of people living in isolated rural areas with no access to potable water. The resultant spread of water-borne diseases, including cholera, is especially severe in developing countries, causing some 60 percent of all infant mortality. There is an urgent need, globally, for practical, inexpensive and sustainable technologies that provide people in rural communities with access to potable water. Solar pasteurisation alleviates health risks The effective microbial purification of drinking water is an important consideration in preventing the transmission of waterborne diseases. Conventional water treatment processes commonly use chemical disinfectants, which are relatively expensive and require skilled labour in its application. While effective in developed areas, the challenge lies in providing a practical treatment solution for communities in rural areas. A team of researchers at the Department of Microbiology and Plant Pathology at the University of Pretoria has addressed this challenge head on with the design of a solar pasteurisation system that enables communities to cost-effectively purify contaminated water. Water samples taken from a river were heated with solar energy at different temperatures and indicators of microbiological pollution used to monitor the disinfection process. The results indicated that solar pasteurisation at temperatures

exceeding 65°C for a minimum of 60 seconds could successfully and cost-effectively decontaminate water. The solar panels are made of black plastic piping. Operating the system is straight forward, requiring skills easily transferable to members of rural communities. Contaminated water is added to the system and exposed to sunlight until the desired temperature is reached. This brings the bacteriological standard of the water to a recognised level for potable water. Depending on the need, systems can be constructed to produce from a few litres to a few thousand litres of potable water per day. The solar pasteurisation system can also be applied to help prevent the spread of diseases such as cholera, which is transmitted through infected drinking water and food contaminated with the Vibrio cholerae bacterium. Sudden large outbreaks such as the one in KwaZulu Natal in August 2000, which developed in the most serious cholera epidemic yet experienced in South Africa with more that 30 000 cases reported in 2001, are usually caused by a contaminated source of drinking water. The greatest risk occurs in communities with poor sanitation and unsafe drinking water. Improvements in water supply and sanitation in rural areas to alleviate health risks are often the more difficult to achieve as it requires technological intervention. The manage-ment of the cholera epidemic in KwaZulu Natal has shown, however, that with the right intervention historically dreaded diseases can be controlled despite large numbers of infections. Detecting microbial waterborne pathogens Population growth and globilisation have

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increased the rapid movement of people across continents, escalating the spread of new strains of waterborne pathogens world-wide. This presents a significant challenge in water resource management, for which comprehensive reviews of the latest available information is fundamentally important. Experts of international standing, led by Prof Eugene Cloete, Head of the Department of Microbiology and Plant Pathology at the University of Pretoria, recently published the book Microbial Waterborne Pathogens. The book is widely regarded as a complete reference book for academics, practitioners, advanced students and regulatory authorities on the microbiological quality and safety of potable water. It reviews the latest information on all the existing and emerging pathogens including bacteria, viruses and protozoa, and their epidemiology. The book looks at pathogen detection methods and control strategies in water resources and supplies, and covers the link between climate and disease, indicating future approaches for dealing with this important aspect as we face of the effects of global climate change. This book makes a valuable contribution to a better understanding of traditional and new strains of waterborne pathogens in its presentation of the latest available information in this field. Helping manage industrial water systems The use of water is integral to most industrial production processes, such as in the mining and food and beverage industries. Given the imperative on these industries to conserve and optimally utilise water resources, two research projects have been undertaken by the Department to assist industry to reduce consumption and alleviate environmental impact. A multi-disciplinary project for the mining industry has resulted in the patenting of an integrated and managed passive treatment process that uses naturally available energy

sources to treat mine waste water. Managed by Pulles Howard and de Lange and incorporating input by researchers of the Universities of Pretoria, Rhodes and Witwatersrand, the process addresses the problem of acidification and salinisation at operating, defunct and closed mines in South Africa. The final phase in the IMPI Process (Integrated Managed Passive treatment process) development programme, currently underway, is the design and implementation of full-scale low cost, low maintenance and self-sustaining treatment systems within the mining industry. And to assist the food and beverage industry to meet ever-increasing food safety requirements, the now internationally patented Rotoscope Biofouling Monitor effectively monitors the formation of unwanted biofilm and releases biocide to disperse the build-up before the biofilm becomes a serious problem. Initially reported on in 2003 when international patents were pending, the Rotoscope – which is significantly more affordable than other monitoring systems – is being manufactured and marketed to the food and beverage industry by BTC Products and Services. Additional research highlights at the Department of Microbiology and Plant Pathology include: • assisting government to develop

policies to improve the water management systems in industry, which involves determining the industries that use water and the quantities used, as well as the amount and composition of the effluent produced looking at bacteria that are resistant to the biocides used to kill them to assist both industry and the manufacturers of the biocides developing biological control methods to combat the Eutrophication of dams, using the bacteria kill the toxin-


producing algae that case the Eutrophication and are harmful to humans and animals and aesthetically problematic

• Investigating, with the CSIR, a viable alternative to waterborne sanitation such as eco sanitation or dry sanitation, for which one thousand dry vault latrines have been installed in KwaZulu Natal.

• examining two eco-friendly disinfection techniques using chlorine dioxide or the electrochemical activation of water, both of which show decided promise for industrial application as well as in the provision of potable water.

Bacterial pathogens in water The research focus entails the development of detection and identification methods, as well as a study of the fate (survival) of water-borne pathogens. Detection, typing and identification methods for Vibrio cholerae in surface and drinking water sources are developed. The prevalence of bacterial pathogens in biofilms associated with drinking water is investigated, as is the survival of pathogens in fresh water sediments. Environmental biotechnology The use of micro-organisms to inhibit pollution is researched. Emphasis is placed on water pollution with special reference to waste water, industrial waste water, industrial effluent cooling water and water supply.

1) Epidemiology and control of spread of grapevine leafroll disease. Financed by Winetech (South African Wine Industry) 2002-2006/ Epidemiologie en beheer van wingerrolblaarsiekte. Befondsing deur Winetech (Suid-Afrikaanse Wyn Industrie). Grapevine leafroll disease is a serious disease of grapevines. A number of viruses are associated with it. Planting material from which viruses have been eliminated remains susceptible to viruses and when planted in vineyards often become infected again. In this project we intend clarifying the epidemiology of the disease in the South

African industry by determining the most important means of spread of the disease by obtaining dynamic spread data within vineyards over a number of years. This will allow us to target the most important sources of infection and means of spread for development and evaluation on methods of control. Wingerdrolblaarsiekte is ‘n baie ernstige siekte van wingerd. Verskeie viruses word met die siekte geassosieër. Voorplantings material, vry gemaak van viruses, bly egter vatbaar en word gereeld her-besmet sodra dit in wingerde uitgeplant word. In hierdie projek beoog ons om meer inligting oor die epidemiologie van hierdie siekte te verkry deur die mees algemene verspreidings metodes van die siekte te bepaal. Om dit te bepaal word die dinamiese verspreidings data van die siekte in wingerde gemonitor oor verskeie seisoene. Hierdeur kan die belangrikste verpreidingsmetodes beheer word deur toepaslike beheerstrategieë te ontwikkel. 2) Prevention of grapevine leafroll disease spread between successive vineyards at the same site. Funding by Winetech 2004-2011. Voorkomming van wingerrolblaarsiekte verspreiding tussen agtereenvolgende wingerde op dieselfde perseël. Befondsing deur Winetech 2004-2011. Infection of certified planting material, free of viruses, by grapevine leafroll disease is a major problem for the South African Wine Industry. A number of sources and means of spread have been identified in South Africa through spatio-temporal analyses of spread of grapevine leafroll disease in foundation- and mother-blocks. Circumstantial evidence has been obtained that leafroll infection of a newly established block occurred due to the presence of grapevine leafroll disease infection in the preceding vineyard on that site. The aim of this project is to confirm the spread of leafroll between two successive vineyard blocks and perform a field experiment designed to assess control methods such as the use of fallow periods and systemic


insecticide use with or without herbicide to prevent the perpetuation of grapevine leafroll infection from a preceding vineyard. Die besmetting van virus-vry, gesertifi-seerde wingerd voorplantingsmateriaal deur wingerrolblaarvirus is ‘n belangrike problem vir die Suid-Afrikaanse Wyn Industrie. Verskeie bronne en verspreidingsmetodes van die siekte is al in Suid-Afrika ge-identifiseer. Omstandigheidsbewyse is verkry van oordraging van rolblaar siekte na nuwe wingerde, weens die teenwoordigheid van die siekte in ‘n vorige wingerd op daardie perseel. Die doel van hierdie projek is om die die verspreiding van rolblaar tussen twee agtereenvolgende wingerde te bevestig, en ‘n veldproef te doen om beheer strategieë soos braklê van grond, sistemiese insekdoder- en onkruiddoder toedienings te ewalueer. 3) Establishment of a diagnostic capacity for the detection of viruses and other graft-transmissible pathogens of Citrus. Funding by Citrus Research International (2005-2007). Vestiging van ‘n diagnostiese vermoë vir die opsporing van viruses en ander ent-oordragbare siektes van Sitrus. Befonds deur Citrus Research International (2005-2007) Rapid, sensitive and accurate diagnosis and identification of pathogens is fundamental to development of strategies for their management and control, whether by phytosanitary legislation, certification schemes, vector control, resistance selection and breeding, or cultivation practices. Development of such techniques is also an essential first-step in most research actions involving such pathogens. In support of the local citrus industry the aim of this project is to establish a diagnostic capacity (ELISA- or PCR-based) locally to detect the major graft-transmissible diseases of citrus. To address the control of citrus tristeza virus (CTV) by cross protection, and to exploit the probable underlying mechanism of RNA-silencing, it is imperative that information on the variability of this virus be obtained locally. Micro-array based analysis is ideally suited to this, and such a technique is being developed.

Vinnige, sensitiewe en akkurate diagnose en opsporingstegnieke vir patogene is onderliggend tot die ontwikkelling van beheer strategieë vir sulke patogene. Dit sluit fitosanitêre beheer, sertifiserings-skemas, vektor-beheer, weerstands-teling, en bewerkingspraktyke in. Die ontwikkeling van sulke tegnieke is ook ‘n belangrike eerste stap in meeste navorsingsprojekte oor sulke patogene. Ter ondersteuning van die Sitrus bedryf is die doel van hierdie projek die daarstelling van ‘n diagnostiese (ELISA en PKR gebaseerde) vermoëe teen al die ent-oordragbare siektes van sitrus. Om die beheer van sitrustristezavirus (CTV) met kruisbeskerming te verbeter, en die moontlike onderliggende “gene-silencing” metode te benut, is dit belangrik verder dat inligting oor die lokale variasie van CTV bepaal word. Daar word beoog om dit te bereik deur die ontwikkeling van ‘n “micro-array chip”. Fusarium diversity in SA The objective of this research programme is to obtain a global idea of the evolution of species in the fungal genus Fusarium. The research focuses strongly on relationships within and among species, but also on deeper taxonomic relationships among sections and/or species complexes. Accordingly, our major goals are to: • characterise Fusarium species that are

of ecological, agricultural, commercial and medicinal value using morphology- and DNA-based approaches;

• analyse the population biology of these important species using cultural and molecular characters; and

• build an overall picture of the relationships among Fusarium groups, sections and species complexes using molecular phylogenetic approaches.

Rhizobial diversity associated with indigenous legumes. Our overall objective is to characterise the diversity of rhizobia associated with Southern African legumes, especially those that are of agricultural, commercial and medicinal value. To accomplish this, we isolate and identify the rhizobial bacteria


from the root nodules of legumes from various regions in Southern Africa. Such identifications are generally achieved with a combination of traditionally used morphology and biochemical tests, as well as DNA-based approaches. These bacteria are also evaluated for their ability to nodulate and to fix atmospheric nitrogen. Ultimately these data provide an indication of the distribution of rhizobial species and their ecological significance for indigenous legumes. ��

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Litchi The South African litchi growers experience a high percentage of losses at the export end of the fruit chain, which prevent them from attaining premium prices on the export markets. Understanding the factors that contribute to postharvest decay and managing it more effectively to ensure quality remains a critical aspect for the industry if future growth is to be ensured. In addition, recent international requirements to ensure product safety have forced the industry to become Good Agricultural Practices compliant and adopt food safety systems such as HACCP and/or BRC. Although producers remain responsible for the product until it is sold at the retail end, they do not control the product once it leaves the farm gate. Reliance on exporters, importers, distributors etc. therefore becomes critical. If handlers of the fruit further down the chain do not similarly comply with basic hygiene standards and careful handling practices, product quality can be severely compromised. A recent study by Prof Korsten’s team on citrus indicate that this might play a far more important role than previously anticipated and that the blame for poor quality should not necessary only be placed on the shoulders of the producer. Litchi, which is a far more fragile fruit, might even be more affected than citrus. Food safety and quality is a shared responsibility and require a holistic approach to achieve the ultimate goal of best quality consistently. Further, a

critical need exists to find a replacement for SO2 fumigation for litchis since the EU and the USA will not accept fruit treated with sulphur. This places pressure on the local industry to urgently find an effective alternative which is part of this project’s main objectives. Mushroom In the commercial cultivation of mushrooms, compost colonized with mushroom mycelium is covered with a casing layer, to initiate development of mushrooms. In this layer the switch from vegetative (mycelium) to reproductive (mushroom) growth takes place. Physical, chemical and microbiological factors determine the suitability of a casing material. Peat neutralized with calcitic lime is the most widely used casing material for mushroom cultivation throughout the world. Its water holding capacity and structural properties are widely accepted as ideal for the purpose of casing. However, problems associated with its use, especially regarding its availability which is directly linked to the depletion of our natural reserves and the alteration of ecosystems, have led to the search for alternative materials. Standard physical, chemical and biological methods need to be defined and used as parameters in the evaluation of different agricultural waste products (i.e. citrus, sugarcane and grape byproducts) as potential casing materials. Physical parameters are essential in defining substrates for casing materials, because the main role of such substrates is to provide the proper physical conditions for mushroom development. The most important parameters are: pH, electrical conductivity, bulk density, porosity and water holding capacity. If so, then it should be possible by means of tests to predict whether a particular substrate has the potential to be a good casing material. Furthermore, this information might allow us to alter a particular casing material to improve on its cropping potential. In order to have performance characteristics at least equal to peat, competitive cost, stable quality, continuity of supply, free from pests and diseases and easy to handle are some


of the characteristics that can be used to screen byproducts. Citrus The South African citrus industry is the 12th largest citrus producer in the world, and the third biggest exporter of the fresh fruit. Currently 60% of all citrus produced in South Africa is exported fresh to mainly European countries. Currently, the industry is negotiating market access into the USA and China which will cause significant growth in this sector. However, with increased free trade comes new restrictions in the form of phytosanitary barriers to trade. Citrus Black Spot caused by Guignardia citricarpa Kiely is one of the most important fruit diseases on citrus in South Africa and other mainly southern hemisphere countries. The disease does not occur in European citrus producing countries and has therefore become a major barrier to trade despite the more than 80 years of unrestricted exports from South Africa to the EU. In order to remain competitive on the European markets and to access new markets, a risk assessment study had to be done to ensure continued access into the EU. Comments and concerns from the EU on the RA document from South Africa have been addressed during the initial phase of the citrus research program. With this new application the industry requires that we develop an effective long term strategy to manage the disease by means of more effective monitoring of inoculum levels, using biological control systems and improving the disease forecasting model to incorporate actual direct monitoring of the pathogen into the model. In addition, ensuring that the South African citrus industry remains competitive on the international markets, it will have to consider new sweeping changes to maximum residue levels required for most pesticides and the continuing loss of postharvest fungicides. In order to ensure top quality produce that can sustain the export distance, new environmentally friendlier control products will have to be developed, registered and commercialized. The second main objective

of this research program was therefore to develop alternative disease control products for the South African citrus industry.

DISEASES OF INDIGENOUS FOOD CROPS GROWN BY RESOURCE-POOR FARMERS

Many of the 20 000 indigenous plant species described in South Africa not only provide for the daily needs of millions of people but are also rich sources of genetic material from which selections can be made for commercial utilisation. The production of food in increasing quantities is a challenge for coexistence of our national and international societies. In this activity the industrialized countries are making important progress. However, in South Africa, a "developing country", there are still difficulties for achieving the production of agricultural products in qualities and quantities sufficient for maintaining a properly sustained population. About half of the food produced for human consumption on land is estimated to be lost through the ravages of insects, fungi and other organisms. Attacks start prior to harvest and continue during subsequent transport and storage. Even a modest reduction in the percentage losses through such causes, will consequently have a not inconsiderable impact on the production levels achieved in a country.

Cowpea

Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important legume crops in Africa. Cowpea grows on a wide variety of soils from sandy to heavy clays but grows better on well-drained ‘sandy substrates’. Cowpea is relatively more tolerant to drought stress than other common legumes. Propagation of cowpea is by seed. Common cowpea is traditionally grown in Africa intercropped with cereals like millet, sorghum or maize, at wide spacing.

Africa has the lowest average yield of cowpea (200kg/ha) as compared to 1ton/ha in the USA and between 500-600 kg/ha in other countries. Among the limiting factors


to cowpea production is diseases and insect pests. Cowpeas are attacked by at least 35 major diseases caused by fungi, bacteria, viruses and nematodes. In other countries the major diseases include Septoria leaf spot S. vignicola and S. vignae, Cercospora leaf spot (C. canescens and C. cruenta), anthracnose, web blight, scab and brown blotch. The research group does surveys and research on the diseases of cowpea on small-holder farms in the Mpumalanga, KwaZulu-Natal and Northern provinces. As the crop is grown in greater abundance, in closer proximity to one another or once monoculture is introduced, the potential threat of diseases and epidemics may become a reality. Authorative and timely disease recognition is crucial. Pathogens need to be recognized quickly in order to be contained and then eliminated before they become so well-established that eradication is no longer a practical option. Even more crucial is the recognition of possible harmful species in or on seeds and plant materials. In both these cases, adequately knowledgeable staff must be readily available for both survey and diagnostic work, and in addition these personnel require speedy channels to access specialists with the necessary resources to advise quickly on problematic cases. Reliance on distant overseas identification centres cannot provide the timely service

vital for effective preventative measures. The programme has been expanded to include Bambara groundnut.

Seed Pathology

Some research is also being done on seed pathology, vigour and fungicide treatment of maize and legumes grown by small-holder farmers. Prof. Aveling is Vice-Chairperson of the Storage Committee of the International Seed Testing Association, member of the Plant Disease Committee of the International Seed Testing Association and member of the Scientific Programme Advisory Committee (SPAC) for the 28th International Seed Testing Association Symposium to be held in Brazil in 2007.

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Molecular biology and virology: Gene manipulation technology is used in the study of aspects of gene expression and protein function in a variety of micro-organisms, including a number of important viruses. Molecular genetic analysis is also implemented in the diagnostics and taxonomy of various important groups of viruses, bacteria and fungi.

1. ADANDONON, A., AVELING, TAS., LABUSCHAGNE, N & AHOHUENDO, BC. 2005. Etiology of and effect of environmental factors on damping-off and stem rot of cowpea in Benin. Phytoparasitica 33: 65-72.

2. ADANDONON, A., AVELING, TAS., VAN DER MERWE, A. & SANDERS, G. 2005. Genetic variation among Sclerotium isolates from Benin and South Africa, determined using mycelial compatibility and ITS rDNA sequence data. Australasian Plant Pathology 34: 19-25.

3. AVELING, TAS & POWELL, AA. 2005. Effect of seed storage and seed coat pigmentation on susceptibility of cowpeas to pre-emergence damping-off. Seed Science and Technology 33(2): 461-470.

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4. BOGALE M; WINGFIELD BD; WINGFIELD MJ; STEENKAMP ET. 2005. Simple sequence

repeat markers for species in the Fusarium oxysporum complex. Molecular Ecology Notes 5:622-624.

5. BRITZ H, COUTINHO TA, WINGFIELD BD, MARASAS WFO & WINGFIELD MJ 2005. Diversity and differentiation in two populations of Gibberella circinata in South Africa. Plant Pathology 54: 46-52.

6. COETSER, S.E. AND CLOETE, T.E. 2005. Biofouling and Biocorrosion in Industrial Water Systems. Critical Reviews in Microbiology. 31:213-232

7. D L COYNE , A TCHABI, H BAIMEY, N LABUSCHAGNE AND I ROTIFA. 2005. Distribution and prevalence of nematodes (Scutellonema bradys and Meloidogyne spp. ) on marketed yam (Dioscorea spp. ) in west Africa. Field Crops Research Vol 96(1)pp142-150.

8. DE GRAAF, J., GOVENDER, P., SCHOEMAN, A.S. AND VILJOEN, A. 2005 Efficacy of pseudostem and pheromone seasonal trapping of the banana weevil Cosmopolites sordidus in South Africa. International Journal of Pest Management 51: 209-218.

9. GOVENDER, V., KORSTEN, L. & SIVAKUMAR, D. 2005. Semi-commercial evaluation of Bacillus licheniformis to control mango postharvest diseases in South Africa. Postharvest Biology and Technology 38: 57-65.

10. H BAIMEY, D COYNE & N LABUSCHAGNE, 2005. Assessment of inoculation methods in evaluating response of yam cultivars to infection by Scutellonema bradys. Nematology 7:375-379.

11. KRITZINGER, Q., LALL, N., & AVELING, T.A.S. 2005. Antimicrobial activity of cowpea (Vigna unguiculata) leaf extracts. South African Journal of Botany 71(1): 45-48.

12. L. H. NEL, C. T. Sabeta, B. von Teichman, J. B. Jaftha, C. E. Rupprecht and J. Bingham. 2005. Mongoose rabies in southern Africa: a re-evaluation based on molecular epidemiology. Virus Research, Vol 109 (2) pp 165-173.

13. Louis H Nel. 2005. Vaccines for lyssaviruses other than rabies. Expert Reviews of Vaccines, Vol 4 (4) pp 533-540

14. MAILA, P.M. and CLOETE, T.E 2005. “Multispecies and Monoculture Rhizoremediation of Polycyclic Aromatic Hydrocarbons (PAHs) from the Soil”. International Journal of Phytoremediation. 7:87-98.

15. MAILA, P.M. and CLOETE, T.E. 2005. Evaluation of microbial communities colonizing stone ballasts at diesel depots. The Environmentalist (Formerly Water, Air & Soil Pollution). 24 (3): 187-193.

16. MALULEKE, R. and CLOETE, T.E. 2005 The use of the Rotoscope as an on-line, real-time, non-destructive method for biofilm monitoring. Water Science and Technology , Vol 52; 211-216

17. MNISI SM, LOUW ME, THERON J. 2005. Cloning and characterization of a carboxylesterase from Bacillus coagulans 81-11. Curr Microbiol. 50, 196-201.

18. NDUNGURU, J., LEGG, J., AVELING, T., THOMPSON, G. & FAUQUET, C. 2005. Molecular biodiversity of cassava begomoviruses in Tanzania: Evolution of cassava geminiviruses in Africa and evidence for East Africa being a center of diversity of cassava geminiviruses. Virology Journal 2: 21 doi: 1186/1743-422X-2-21.

19. NDUNGURU, J., TAYLOR, N.J., YADAV, J., ALI, H., LEGG, J., AVELING, T., THOMPSON, G. & FAUQUET, C.M. 2005. Application of FTA paper technology for sampling, recovery and molecular characterization of viral pathogens and transgenes from plant tissues. Virology Journal 2:45 doi:10.1186/1743-422X-2-45

20. OBERHOLSTER, P.J., BOTHA, A-M., MULLER, K. and CLOETE, T.E. 2005. Assessment of the genetic diversity of geographically unrelated Microcystis aeruginosa using amplified fragment length polymorphisms (AFLPs). African Journal of Biotechnology, Vol 4 (5), pp.


389-399 21. OBERHOLSTER,P.J., BOTHA, A.-M. and CLOETE, T.E. 2005. Using a battery of

bioassays, benthic phytoplankton and the AUPR PVAP method to monitor long-term coal tar contaminated sediment in the Cache la Poundre River. Water Research. 39; 4913-4924

22. PAUL, I., VAN JAARSVELD, A.S., KORSTEN, L. AND HATTINGH, V. 2005. The potential global geographical distribution of Citrus Black Spot caused by Guignardia citricarpa (Kiely): likelihood of disease establishment in the European Union. Crop Protection 24: 297-308.

23. PAVLIC D, SLIPPERS B, COUTINHO TA, GRYZENHOUT M & WINGFIELD MJ 2005. Lasiodiplodia gonubiensis sp. nov., a new Botryosphaeria anamorph from native Syzygium cordatum in South Africa. Studies in Mycology 50: 313-322.

24. SILIMELA, M. AND KORSTEN, L. 2005. Effect of wool-lined plastic caps impregnated with Bacillus licheniformis or copper oxychloride and sun-protector to prevent sunburn and control mango fruit diseases. Journal of Horticultural Science & Biotechnology 80: 512-516.

25. SIVAKUMAR, D., REGNIER, T., DEMOZ, B. AND KORSTEN, L. 2005. Effect of different postharvest treatments on overall quality retention of litchi fruit during low temperature storage. Journal of Horticultural Science & Biotechnology 80(1): 32-38.

26. SLIPPERS B, FOURIE G, CROUS PW, COUTINHO TA, WINGFIELD BD, CARNEGIE AJ & WINGFIELD MJ 2005. Speciation and distribution of Botryosphaeria spp. on native and introduced Eucalyptus trees in Australia and South Africa. Studies in Mycology 50:343-358.

27. SLIPPERS B, JOHNSON GI, CROUS PW, COUTINHO TA, WINGFIELD BD & WINGFIELD MJ 2005. Phylogenetic and morphological re-evaluation of the Botryosphaeria species causing diseases of Mangifera indica. Mycologia 97: 99-110.

28. SLIPPERS B, SUMMERELL BA, CROUS PW, COUTINHO TA, WINGFIELD BD & WINGFIELD MJ 2005. Preliminary studies on Botryosphaeria species from Southern Hemisphere conifers in Australasia and South Africa. Australasian Plant Pathology 34:213-220.

29. STEENKAMP ET; WRIGHT J; BALDAUF SL. 2005. The protist origins of animals and fungi. Molecular Biology and Evolution 23(1): 93-106.

30. WOLMARANS, E., DU PREEZ, H.H., DE WET, C.M.E. and VENTER, S.N. 2005. Significance of bacteria associated with invertebrates in drinking water distribution networks. Water, Science and Technology, 52(8), 171-175.

1. PIETERSEN, G. 2005. Spatial and temporal analysis of spread of grapevine leafroll disease in South Africa. IX International Plant Virus Epidemiology Symposium. Lima, Peru 4-7 April, 2005.

2. WEYER, J., VILJOEN, G. J., & NEL, L H., 2005. Alternative recombinant poxvirus vaccines for rabies. Proceedings of the 7th Southern and Eastern African Rabies Group/World Health Organization Meeting, Manzini, Swaziland. Editions Foundation Marcel, Merieux 17, rue Bourgelat, 69002 Lyon – France. pp 79-84.

3. SABETA, C. T., & NEL, L.H., 2005. Canid rabies in South Africa and Zimbabwe – a review. Proceedings of the 7th Southern and Eastern African Rabies Group/World Health Organization Meeting, Manzini, Swaziland. Editions Foundation Marcel, Merieux 17, rue Bourgelat, 69002 Lyon – France. pp 135-139.

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1. COUTINHO TA - 2005: Introduction and Prospectus on the survival of Ralstonia

solanacearum. In: Bacterial wilt disease and the Ralstonia solanacearum species complex. Ed. By C. Allen, P Prior and AC Hayward. APS, St Paul, USA.

2. NEL, L.H., & WEYER, J. “Emerging infectious waterborne diseases: Viral agents”. In: Microbial Waterborne Pathogens. TE Cloete, J Rose, LH Nel and T Ford (eds). IWA publishing, London ISBN 1 84339 055 8. pp 78-88

3. NEL, L.H., & MARKOTTER, W. “Emerging infectious waterborne diseases: Bacterial agents”. In: Microbial Waterborne Pathogens. TE Cloete, J Rose, LH Nel and T Ford (eds). IWA publishing, London ISBN 1 84339 055 8. pp 55-77

4. NEL, L.H., MARKOTTER, W., & WEYER, J. “Emerging infectious waterborne diseases: Protozoal agents”. In: Microbial Waterborne Pathogens. TE Cloete, J Rose, LH Nel and T Ford (eds). IWA publishing, London ISBN 1 84339 055 8. pp 89-99

1. Prof T E Cloete: Editor: Basic and Applied Microbiology, 2005 2. Prof J Theron: Editor: Proceedings of the Electron Microscopy Society of Southern Africa,

Volume 35: Zoology and Medicine Divisions 1. NEL, L.H., CROWTHER, J & VILJOEN, G.J., (Authors) - 2005. “Molecular Diagnostic PCR

Handbook. Springer, Dordrecht, The Netherlands. 307 pages ISBN 1-4020-3403-2.

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Invited speaker 1. CLOETE, T.E. and THANTSHA, M.S. Probiotics. What we know and what we need to

know. SAAFost Conference on Probiotics. Midrand, November 2005. 2. KORSTEN, L. 2005. Towards one food control. SAAFoST Food Safety Initiative, 2004-

2006. 14 April 2005, Radissons Hotel, Cape Town. 3. PIETERSEN, G., 2005. Epidemiology and Control of Grapevine leafroll virus. Vinpro Farmers

Day, Robertson and Worcester 11 May 2005. 4. PIETERSEN, G., 2005. Epidemiology and Control of Grapevine leafroll virus. Vinpro Farmers

Day, Malmesbury and Vredendal, 12 May 2005. 5. PIETERSEN, G., 2005. Epidemiology and Control of Grapevine leafroll virus. Vinpro Farmers

Day, Vredendal, 12 May, 2005. 6. PIETERSEN, G., 2005. Epidemiology and Control of Grapevine leafroll virus. Ernita Open

Day, Wellington, 22 June, 2005. 7. VENTER, SN. Food and waterborne disease and the traveller. Invited speaker at the training

course for the Diploma in Travel Medicine organised by the South African Society of Travel Medicine, Johannesburg, 20-22 May 2005.

Papers

1. AVELIING, T.A.S. 2005. CHAIRPERSON: Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay. Chairperson of Session: Pathogen identification & characterization.

2. BEKKER T, LABUSCHAGNE N, KAISER C. 2005. Application of soluble silicon to avocado Persia Americana Mill plants for the prevention and cure of Phytophthora Cinnanmoni root rot. Combined Congress 2005 of the Soil Science Society of S A, the S A Society of Crop Production, the S A Weed Science Society, and the SA Society for Horticultural Sciences.

3. BRADY, C.L., VENTER, S.N., CLEENWERCK, I., VANCANNEYT, M., SWINGS, J. and COUTINHO, T.A. 2005. Development of an AFLP-based typing systems for the genus Pantoea. Oral presentation a the 43d South African Society for Plant Pathology, Hartenbos, 23-26 January 2005.

4. COYNE D L, WILLIAMSON, V M, LALBANNA, A B, TCHABI, A, BAIMEY, H & LABUSCHAGNE, N. 2005. Analysis of the pathogenic, morphological and genetic variability of Scutellonema bradys on yam in West Africa .17th Symposium of the NSSA 22-25 May, 2005.

5. DU PLOOY, H., AVELING, T.A.S. & LABUSCHAGNE, P.M. 2005. Mycogone perniciosa on Agaricus bisporus. 15-17 February 2005. South African Mushroom Grower’s Conference, Port Elizabeth.

6. HAMMERBACHER, A., T.A. COUTINHO, B.D. WINGFIELD & M.J. WINGFIELD. (2005) Effect of inoculum concentration, plant vigour and wounding on infection of Pinus patula by Fusarium circinatum. Proceedings of the 43rd Annual Congress of the Southern African Society for Plant Pathology, Hartenbos, Mossel Bay 23-26 January.

7. KORSTEN L. Measurement Conference, National Laboratory Association. 5-7 September 2005. Emperors Palace Convention Resort, Johannesburg.

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8. KORSTEN, L. 2005. Ethics in laboratories, what you should know and be prepared for. Test and Measurement Conference 2005. Emperors Palace Convention Resort. 5-7 September 2005.

9. KORSTEN, L. 2005. Improving litchi quality and shelf life through the export chain focusing on various aspects from production to consumption. Litchi Research Symposium, Tzaneen Country Lodge, 25 May 2005. .

10. KORSTEN, L. 2005. Pre-harvest factors on post-harvest decay and loss of quality and shelf life. Litchi Research Symposium, Tzaneen Country Lodge, 25 May 2005.

11. KRITZINGER, Q. & AVELING, T.A.S. 2005. Prospects and problems associated with cowpea cultivation by resource poor farmers in Mpumalanga, South Africa. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay.

12. LABUSCHAGNE, P.M., AVELING, T.A.S. & KORSTEN, L. 2005. Mushroom casing. 15-17 February 2005. South African Mushroom Grower’s Conference, Port Elizabeth.

13. LOMBARD, L., T.A. COUTINHO AND M.J. WINGFIELD (2005) Cylindrocladium pauciramosum infecting Acacia mearnsii seedlings in South Africa. Proceedings of the 43rd Annual Congress of the Southern African Society for Plant Pathology, Hartenbos, Mossel Bay 23-26 January.

14. MEYER, L., JACOBS, R. AND KORSTEN, L. Citrus Black Spot a Phytosanitary risk for South Africa. Test and Measurement Conference 2005. Emperors Palace Convention Resort 5-7 September 2005.

15. PIETERSE, Z., AVELING, T.A.S. & LABUSCHAGNE, P.M. 2005. Interaction between Agaricus bisporus and Mycogone perniciosa. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay.

16. PIETERSE, Z., AVELING, T.A.S. & LABUSCHAGNE, P.M. 2005. Interaction between Agaricus bisporus and Mycogone perniciosa. 15-17 February 2005. South African Mushroom Grower’s Conference, Port Elizabeth.

17. TRUTER, M. & KORSTEN, L. 2005. A sampler to dertermine the available Guignardia citricarpa inoculum on citrus leaf litter. SASPP congress, Hartenbos.

18. TRUTER, M., PAUL, I., MEYER, L. & KORSTEN, L. 2005. Citrus black spot – A review. SASPP Congress, Hartenbos.

Posters 1. ADANDONON, A., AVELING. T.A.S., LABUSCHAGNE, N. & TAMO, M. 2005. Control of

Sclerotium-caused cowpea damping off and stem rot using Moringa oleifera extract and biocontrol agents. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. Hartenbos Beach Resort, Mossel Bay, 23-26 January 2005.

2. ATHMAN, S.Y., DUBOIS, T., GOLD, C.S., COYNE, D., LABUSCHAGNE, N. AND VILJOEN, A. 2005. Inhibitory effects of culture filtrates of endophytic Fusarium oxysporum isolates to motile stages of the banana nematode, Radopholus similis Cobb. 17th Symposium of the Nematology Society of Southern Africa, South Africa, 21-25 May 2005.

3. BELGROVE, A., NEL, B. AND VILJOEN, A. 2005. The application of non-pathogenic Fusarium oxysporum endophytes for the biological control of Fusarium wilt of banana. Joint congress of the 43rd Congress of the Southern African Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23 – 26 January 2005.

4. BOSHOFF J, LABUSCHAGNE N & REGNIER T. 2005 Determining the modes of action of potential biocontrol agents against Pythium wilt and root rot of lettuce. 43rd SASPP Congress. 13-26 Jan 2005. Hartenbos Beach Resort Mosselbay.


5. DEGRAAF, J. GOVENDER, P., VILJOEN, A. AND SCHOEMAN, A.S. 2005. Population

dynamics of the banana weevil, Cosmopolitus sordidus (Germar) in South Africa. 15th Meeting of the Entomological Society of South Africa, Grahamstown, South Africa. 10-13 July 2005.

6. DU PLOOY, H., AVELING, T.A.S. & LABUSCHAGNE, P.M. 2005. Development of wet bubble disease (Mycogone perniciosa) during the various cultivation stages of Agaricus bisporus. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay.

7. FOURIE G; STEENKAMP ET; GORDON TA; VILJOEN A. A. 2005. Multigene phylogeny determines the relatedness among vegetative compatibility groups (VCGs) within Fusarium oxysporum f.sp cubense. Proceedings of the 43rd Congress of the SASPP, Stellenbosch.

8. FOURIE, G., STEENKAMP, E., GORDON, T.A., AND VILJOEN, A. 2005. A multigene phylogeny determines the relatedness among vegetative compatibility groups (VCGs) within Fusarium oxysporum f.sp. cubense. Joint congress of the 43rd Southern African Plant Pathology Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23-26 January 2005.

9. GEVERS, T., GROENEWALD, S. AND VILJOEN, A. 2005. Comparative Analysis of a MAP kinase-coding gene (fmk) in Fusarium oxysporum. Joint congress of the 43rd Congress of the Southern African Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23 – 26 January 2005.

10. GREYLING, I., BRADY, C.L., NAKABONGE, G., VENTER, S.N., CLEENWERCK, I., VANCANNEYT, M., SWINGS, J., ROUX, J., WINGFIELD, M.J. and COUTINHO, T.A. 2005. Bacerial blight and die-back of Eucalyptus in Uganda. Poster presentation at the 43d South African Society for Plant Pathology, Hartenbos, 23-26 January 2005.

11. JACOBS, A., P.S. VAN WYK, W.F.O. MARASAS, B.D. WINGFIELD, T.A. COUTINHO & M.J. WINGFIELD (2005) A new Fusarium species in the Gibberella fujikuroi complex from pineapple in South Africa. Proceedings of the 43rd Annual Congress of the Southern African Society for Plant Pathology, Hartenbos, Mossel Bay 23-26 January.

12. KALONJI, J.B., AVELING, T.A.S., LABUSCHAGNE, N. & VAN DER WAALS, J. 2005. Efficacy of fungicides and biological control agents against seedling diseases of lettuce. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay.

13. KVAS M; MARAIS GJ; STEENKAMP ET; LÜBBEN A. 2005. Mycotoxigenic fungi associated with commercial pet food. Proceedings of the 43rd Congress of the SASPP, Stellenbosch.

14. MEHL, J.W.M., A. HAMMERBACHER, T.A. COUTINHO, M.J. WINGFIELD & B.D. WINGFIELD (2005) Detection of the pitch canker fungus, Fusarium circinatum, in pine seeds. Proceedings of the 43rd Annual Congress of the Southern African Society for Plant Pathology, Hartenbos, Mossel Bay 23-26 January 2005.

15. MEYER, J.B., PIETERSEN, G., NEL, L.H., and KASDORF, G.G.F., 2005. Characterisation of BSV isolates and the development of a TAS ELISA detection method. Proceedings of the 43rd Congress of the South African Society for Plant Pathology. Hartenbos, Mossel Bay, 23-26 January, 2005, Pg. 103

16. MEYER, J.B., VAN DER MERWE, M, PIETERSEN, G., and KASDORF, G.G.F., 2005. Reliable detection of banana mild mosaic virus with a nested PCR designed for members of the Foveaviridae. Proceedings of the 43rd Congress of the South African Society for Plant Pathology. Hartenbos, Mossel Bay, 23-26 January, 2005, Pg. 104


17. MUNRO, C., FOURIE, G. AND VILJOEN, A. 2005. The Application of PCR-RFLP’s for rapid

identification of Mycosphaerella species from Banana leaves in South Africa. Joint congress of the 43rd Congress of the Southern African Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23 – 26 January 2005.

18. RAMUSI, T.M., AVELING, T.A.S., VAN DER WAALS, J. & LABUSCHAGNE, N. 2005. Biological and fungicidal control of seedling diseases of cowpea caused by Fusarium solani, Pythium sp. and Rhizoctonia solani. Joint Congress of Southern African Society for Plant Pathology, African Mycological Association and Medical Mycology in Africa. 22-25 January 2005. Hartenbos Beach Resort, Mossel Bay.

19. SORRIL, M.J., THERON, J., BÖHMER, B., LEKOANA, T., MAREE, F., ESTERHUYSEN, J., PHIRI, O.C., VOSLOO, W. AND VAN RENSBURG, H.G. (2005). Application of recombinant SAT2 foot-and-mouth disease virus non-structural 3ABC polyprotein, in a diagnostic ELISA. South African Society for Biochemistry and Molecular Biology XIXth Conference. 16 – 20 January 2005, Stellenbosch, South Africa.

20. SUTHERLAND, R., ESCALANT, J.V., KUNERT, K. AND VILJOEN, A. 2005. Applications of cell and tissue culture in banana (Musa spp.). Joint congress of the 43rd Southern African Plant Pathology Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23-26 January 2005.

21. SUTHERLAND, R., ESCALANT, J.V., KUNERT, K. AND VILJOEN, A. 2005. Establishment of a transformation facility for engineering banana for disease and pest resistance in South Africa. Joint congress of the 43rd Southern African Plant Pathology Society for Plant Pathology, 5th African Mycological Association, and inaugural symposium of the African Society for Medical Mycology, Hartenbos, South Africa, 23-26 January 2005.

Invited speaker 1. KORSTEN, L. 2005. Advances in control of postharvest diseases in tropical fresh produce.

International Conference on Postharvest Technology and Quality Management in Arid Tropics. Sultan Qaboos University, Sultanate of Oman, 24-26 January, Oman.

2. KORSTEN, L. 2005. Factors affecting the flow of Africa’s food exports. Accreditation Awareness Workshop, 15 June, Lusaka, Zambia. Organised by Ministry of Commerce, Trade and Industry, Republic of Zambia.

Papers 1. ADANDONON, A., AVELING, T.A.S. & TAMO, M. 2005. A new laboratory technique for

rapid screening of cowpea cultivars for resistance to damping-off and stem-rot caused by Sclerotium rolfsii. 1st International Edible Legume Conference in conjunction with 4th World Cowpea Congress, 17-21 April 2005, International Convention Centre, Durban, South Africa.

2. LH NEL. Lyssaviruses in Africa: Recent experiences in South Africa. The 16th International Conference on Rabies in the Americas. Ottawa, Ontario, Canada 2005

3. PIETERSEN, G. 2005. Spatial and temporal analysis of spread of grapevine leafroll disease in South Africa. IX International Plant Virus Epidemiology Symposium. Lima, Peru 4-7 April,

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2005. 4. SURRIDGE, A.K.J., MOLBELA, I.P., WEHNER, F.C. AND CLOETE, T.E. 2005. Molecular

identification and confirmation of toluene and naphthalene degrading capacity of bacteria isolated from the rhizosphere of weeds in a polyaromatic hydrocarbon polluted soil in South Africa. Diffuse pollution specialist conference (WISA). 9-12 August. Sandton Convention Center, Johannesburg, South Africa.

Posters 1. AVELING, T.A.S., KRITZINGER, Q., PAKELA, Y.P. & REGNIER, T. 2005. Seed

pathological aspects of cowpea II. 4th Annual Conference: USAID-African Partnership in Biotechnology: The path to product development. 15-17 November 2005, Centurion Lake Hotel, Centurion, South Africa.

2. BÖHMER, B., SORRIL, M.J., MAREE, S., THERON, J., MAREE, F.F., ESTERHUYSEN, J., LEKOANA, T., PHIRI, C., VOSLOO, W. AND VAN RENSBURG, H.G. (2005). Recombinant SAT2 foot-and-mouth disease virus non-structural 3ABC polyprotein, in a diagnostic ELISA. 2005 EUROpic: XIIIth Meeting, 23-29 May 2005, Lunteren, The Netherlands.

3. KIGGUNDU, A., KUNERT, K., VILJOEN, A.. PILLAY, M., GOLD, C. AND MICHAUD, M. 2005. Engineered cysteine proteinase inhibitors (cystatins) for the transgenic control of banana weevil (Cosmopolites sordidus). The 2nd Meeting on Biotechnology, breeding and Seed Systems for African crops, Rockefeller Foundation and Kenya Agricultural Research Institute, Nairobi, Kenya 24th – 27th January 2005.

4. LE ROUX, W.J. and VENTER, S.N. 2005. Population dynamics of V. cholerae in an inland catchment in South Africa. Poster presentation at Vibrio 2005, Ghent, Belgium, 7-8 November 2005.

5. MAREE, F.F., BÖHMER, B., LEKOANA, T., ESTERHUYSEN, J., THERON, J., DE BEER, T., JOUBERT, F., VOSLOO, W. AND VAN RENSBURG, H.G. (2005). Phylogeny, antigenic variation and epitope prediction of the capsid-coding regions of the South African Territories (SAT) types of foot-and-mouth disease virus. 2005 EUROpic: XIIIth Meeting, 23-29 May 2005, Lunteren, The Netherlands.

6. PIETERSEN, G. 2005. Spatial and temporal analysis of spread of grapevine leafroll disease in South Africa. IX International Plant Virus Epidemiology Symposium. Lima, Peru 4-7 April, 2005.

7. RUSHWORTH, S., SAID, M.D. and VENTER, S.N. 2005. Cholera outbreak in KwaZulu-Natal, South Africa: 2000 – 2004. Poster presentation at Vibrio 2005, Ghent, Belgium, 7-8 November 2005.

8. VILJOEN, A., GEVERS, T., GROENEWALD, S. AND VAN DEN BERG, N. 2005. Comparative analysis of a pathogenicity-encoding and cell wall-degrading gene in Fusarium oxysporum f.sp. cubense. 2005 Annual meeting of the American Phytopathological Society, Austin TX, USA, 30 July – 3 August 2005.


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MSc – MICROBIOLOGY 1. Ms A Ramaite: The selection of lactic acid bacteria to be used as starter cultures for Ting Production (2005) Supervisor: Prof T E Cloete 2. Ms I Molobela: Development of rhizoremediation as a treatment technology in the removal of Polycyclic

aromatic hydrocarbons (PAH) from the environment. (2005) Supervisor: Prof T E Cloete 3. Ms P Storey:

The role of a second RGD motif in the 1D protein of a Namibian SAT1 foot-and-mouth disease virus for target cell attachment. (cum laude) Supervisor: Prof J. Theron Co-Supervisor: Dr H.G. van Rensburg

4. Me HM Said Clinical relevance of Salmonella enterica isolated from water and food in Eritrea. (2005) Supervisor: Prof SN Venter

5. Draginja Pavlie Botryosphaeria species on native South African Syzygium cordatum and their potential threat to Eucalyptus (2005) Supervisor: Prof TA Coutinho Co-Supervisor: Prof MJ Wingfield

7. Ms CL Brady Taxonomy of Pantoea associated with bacterial blight of Eucalyptus 2005

Supervisor: Prof SN Venter Co-Supervisor: Prof TA Coutinho

8. Ms LM Burke Fate of Salmonella Typhimurium in biofilms of drinking water distribution systems. Supervisor: Prof SN Venter Co-Supervisor: Prof VS Brözel

9. Mr WJ Le Roux Polulation dynamics of Vibrio cholerae in the Vaal Barrage catchment.

Supervisor: Prof SN Venter

MSc – PLANT PATHOLOGY

1. Ms V Govender: MSc Plant Pathology: Evaluation of biological control systems for the control of post-harvest diseases in mango Supervisor: Prof L Korsten Co-supervisor: Dr T Regnier

2. Ms W Havenga: MSc Microbiology Cum Laude: Mode of action of Bacillus subtilis as biocontrol agent of avocado postharvest diseases Supervisor: Prof L Korsten

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3. Ms B Demoz: MSc Plant Pathology, Cum Laude: Honeybee dispersal of antagonist to avocado flowers to control stem-end rot pathogens Supervisor: Prof L Korsten

6. Mrs M. Truter (MSc cum laude): Etiology and alternative control of potato rhizoctoniasis in South Africa.

Supervisor: Prof F C Wehner 7. M M Geldenhuis

Studies on fungi associated with dying Schizolobium parahybum in Ecuador. (2005) Supervisor: Prof MJ Wingflied Co-Supervisor: Prof J Roux and Prof BD Wingfield

8. J. Boshof Biological control of Pythium wilt and root rot in hydroponically grown lettuce. Promotor: Prof N Labuschagne Co-promotor: Prof L Korsten

MINSTAGRAR (PLANT PATHOLOGY) 1. Ms Fhumalani Mashau:

MInstAgrar (Plant Protection) Cum Laude: Risk assessment of fire blight on pears Supervisor: Prof L Korsten

PhD – PLANT PATHOLOGY 1. Mr Q. Kritzinger:

PhD 2005 Mycotoxins and medicinal compounds of cowpea Supervisor: T.A.S. Aveling Co supervisors: N. Lall

2. Mr J. Ndunguru: PhD 2005 Molecular characterisation and dynamics of cassava mosaic geminiviruses in Tanzania Supervisor: T.A.S. Aveling Co supervisors: G. Thompson, J. Legg, C. Fauquet

3. Mrs E.J. van der Linde: PhD 2005 Ergot of nut sedge in South Africa Supervisor: F.C. Wehner Co supervisors : T.A.S. Aveling

4. B. Hugues: Scutellonema Bradys as a pathogen of yam in Benin. Promotor: Prof N Labuschagne Co-promotor: Prof A H Mac Donald; Dr D Coyne

university of pretoria · mrs e m du plessis mr a hassen mr h baimey ms s athman ms s capindu mr a...

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