Dr Marieka Gryzenhout
Position
Senior Lecturer
Department
Genetics
Address
GENETICS
IB 116
R7352
UV
Telephone
051/401-2857
Office
Biology Building
Information

Short CV

Since my post-graduate studies at the University of Pretoria, I have been passionate about studying fungi (mycology). During my PhD I developed a world monograph of the important tree pathogen fungal family Cryphonectriaceae. The book publication was preceded by 25 internationally reviewed publications, which was also done as collaborations with fellow students or other scientists. My research instilled in me a hunger to discover fungal species, describe them and untangle taxonomic problems. Moreover, I have a practical approach and making my knowledge available to diverse end-users who do not necessarily have the appropriate skills and background, is gratifying. Skills in classical taxonomy, especially when paired with molecular approaches, are scarce in any biological field. My current position as biosystematist in the Department of Genetics at the University of the Free State, is thus conducive to follow my research ideals fully.

During my Claude Leon post-doctoral fellowship at UP I developed a project with Prof Bernard Slippers to use next generation sequencing to study fungal endophytes of trees. This Thuthuka project funded three MSc students of which I was the primary supervisor. This project set the stage to combine classical taxonomical approaches with deep amplicon sequencing approaches to study the fungal compliments in natural substrates.

After my move to UFS as senior lecturer, I continued my studies on fungi. I lectured in the Plant Pathology division of the Department of Plant Sciences and thus expanded my experience in agriculture and plant pathology. It is, however, more as a mycologist for which I am known nationally and internationally. In my current position in the Department of Genetics, I thus still use fungi as subjects to practice biosystematics and biodiversity associated studies.

I engage with the public to promote the study and bioexploration of fungi. This was in the form of outings, education and identifications for the public, and resulted in a number of popular articles and a pocket guide in book form that is still sold. My current involvement with the endeavor MushroomMap hosted by the University of Cape Town will lead to the publication of more guides, continued engagement of citizen scientists (Gryzenhout 2015) and hard core research when proper distributions and records of our indigenous fungi are mapped and modelled for the first time.

Publications

Please see CV.

Publications (Short List)

Please see CV.

Research

My current and future studies still continue on the theme of biosystematics and the related topics of biogeography, biodiversity and diagnostics. Overall, projects are now incorporating comparisons not only within tree species or between different tree species, but also incorporating other types of plants such as grasses and shrubs, and other niches such as soil, water and air. Comparisons are also done in agroecosystems vs. natural or pristine ecosystems.

For this a model group of fungi is used with the eventual aim to study patterns of infection, to determine if fungal species are restricted to certain niches or areas of endemism, or whether they occur more commonly as previously thought. In the process a number of novel species will be discovered and described, which will aid in resolving existing taxonomical issues in the model group. Ecological information, geographical distributions and host associations of known species will be expanded and will contribute to our understanding of these species, especially if these fungi are problem species in plant, food or health security.

The model group selected for the various surveys and comparisons is the important genus Fusarium that causes problems as contaminants and rotters of food, toxin producers, and pathogens of humans, animals and plants. Species are known from all continents and substrates on earth. An established but developing phylogenetic and taxonomic base is already available but still open for significant improvement, revision and addition. The first of our publications along this theme (Gryzenhout et al. 2016) already showed the occurrence of a grain crop pathogen in an indigenous native tree and pecan, without showing external disease symptoms.  Manuscripts planned for 2017 represent new disease reports, and reports on novel species and a high level of biodiversity across South Africa.

World wide distributions, including in Africa, exists for some Fusarium species but overall species in this genus is vastly under sampled and poorly characterized relative to recent classifications. This group has great potential for novel and groundbreaking research that is also internationally relevant. Besides generating a large amount of novel data, our research will significantly contribute to the understanding of the systematics, biology, ecology and impact of these fungi across the world. Due to the incredibly high citations linked to Fusarium species (2268 Fusarium related publications in 2016 alone), our research will be highly citable and relevant internationally and will be conducive to finding solutions to the problems these fungi cause.

Current surveys focus mostly on soils from the various biomes of South Africa. This is due to the common occurrence of Fusarium in soil, and the fact that windblown fusaria from plants may also end up in top soils. To facilitate a series of publications, surveys have been planned according to ecological questions and to investigate the occurrence of plant and human pathogens in these different areas and niches. Conventional isolations have been and will be done on samples across South Africa to build a collection of isolates that are essential for morphological descriptions, multi-gene phylogenetic analyses and accurate identification. A parallel environmental sequencing approach is also followed for which Fusarium specific techniques are being refined by an MSc student. Such a technique would enable large scale and higher resolution surveys to generate in depth distribution data.

Other projects include comparisons of fusaria as endophytes from indigenous plant species. During collections, soils are also collected from the direct area to enable comparisons between plant- and soil-associated fusaria. Plants also include crops where the co-occurrence of fusaria can be compared between the different crops, but also with naturally occurring plants in the surrounding environment. Since Fusarium spp. are important pathogens of crops, such studies will enhance our knowledge of the ability of such species to infect different plant tissues and substrates, and their ability to occur elsewhere than the crop plant. Such information will improve control strategies.

MushroomMap is an online initiative driven by a team of scientists and citizen scientists.  Through the involvement of citizen scientists (Gryzenhout 2015) it is possible for the first time to make a hugely significant impact on biodiversity assessment of fungi in Southern Africa.  Research using this tool aims to document accurate distributions of target fungi for the first time and to compile lists of fungal species that are based on observations and not just past collection data.  Biosystematics will also be used to describe novel species that are prominent, but also to aid in predicting phylogeography and biodiversity. 

Generated information will be incorporated in future in the first Fungal Atlas for South Africa, and thus will for the first time make fungi as visible as other biological groups such as birds, for which such endeavors have already been active.  Datasets are crucial to put fungi in a more prominent place in biodiversity and conservation circles.  Due to ongoing efforts in Africa (Gryzenhout et al. 2010, 2012, Ngala & Gryzenhout 2010, Gryzenhout 2015) but also on other continents to promote the awareness of the importance of fungal conservation, our work is thus important internationally as well.


Courses Presented

GENE2626 (Molecular Genetics)

GENS6824 (Molecular Biosystematics)

Community Service


Service Learning



FACULTY CONTACT

Faculty Manager: Velaphi Makgwahla
T: + 27 51 401 3199
E: makgwahlamvt@ufs.ac.za

Marketing Manager: Elfrieda Lötter
T: +27 51 401 2531
E: lottere@ufs.ac.za

NatAgri for next to contact block

We use cookies to make interactions with our websites and services easy and meaningful, to better understand how they are used and to tailor advertising. You can read more and make your cookie choices here. By continuing to use this site you are giving us your consent to do this.

Accept