Mycology Research

Mycological researchis carried out in two main areas:

1. Developmental aspects of fungi, including:
   • Physiology and nutrition of growth and sporulation of fungi.
   • Morphogy, structure and ultrastructure of spore formation.
2. Biology of fungal-plant interactions, including:
   • Physiology and biochemistry of ericoid mycorrhizas.
   • Management of vesicular-arbuscular mycorrhiza (VAM).
   • Fungal pathogenesis of cassava.
   • The biochemistry of disease resistance mechanisms in plants.

• Conidiospores and conidiogenesis in selected species of Fungi Imperfecti from southern Africa.
• Litter accumulation and decomposition in a Pinus patula plantation and the role of ectomycorrhizas in nutrient cycling.
• Resistant and susceptible responses in Lagenaria mascarena to infection by powdery mildew under different conditions of light quality and intensity.
• The biochemistry of wall-bound enzymes of ericoid mycorrhizal fungi.
  

• Dr Colin Straker
• Dr John Fletcher

• MICHAEL BARRETO (MSc) Supervisors: Dr. Colin Straker and Professor Alan Critchley

  Factors affecting the responses of selected fungi to extracts from selected macroalgae from KwaZulu-Natal, South Africa

  Fungal bioassays were used to study the following factors affecting the biological activity of macroalgal extracts:

  1. The choice of extraction solvent,
  2. Seasonal variations in biological activity,
  3. The effects of storage of the macroalgal material prior to extraction, and
  4. The effects of diluting macroalgal extracts on mycelial growth and fungal spore germination

  Ethanol was found to be the most effective solvent for extracting biologically active compounds from seaweeds. A general change in biological activity was observed on the extracts from the material collected in summer. The experiments on the effects of storage of the macroalgal material prompted many questions and ideas for future work. Hormesis was observed and the LD50 values obtained showed non-linear responses in response to low concentrations of some of the macroalgal extracts. Future work would involve characterization of the macroalgal extracts to determine the biochemical basis of the observations.

• ANTHONY HILDITCH (MSc) Supervisor: Dr Colin Straker

  The effects of arbuscular mycorrhizal fungi and the rhizobacterium, Enterobacter cloacae 6.11 pDTC on growth of cassava (Manihot esculenta) in greenhouse trials under different phosphorus and water conditions.

  This project is an investigation into the influence of an indigenous AM fungal cocktail, which has been solated from local acidic soils, propagated and grown in bulk as an inoculum source, and a drought-tolerant rhizobacterium, on the growth of cassava under different constraints imposed by soil phosphorus and water availability. The project has also undertaken a detailed identification of the AM fungal speciesisolated from local soils supporting cassava growth.

• MAESELA KEKANA (MSc) Supervisors: Dr Colin Straker and Professor Mary Scholes

  Studies on a cassava /cowpea intercrop system and the influence of arbuscular mycorrhiza, N₂-fixing bacteria and fertilizers on plant growth.

  We are trying to determine the effect of introduced arbuscular mycorrhiza, Rhizobium, and inorganic fertilizers on establishment and yield of a legume crop and a cassava crop in an intercropping system. The second important aspect of the project is to determine the synergistic interactions between the Rhizobium and arbuscular mycorrhiza.

• ISABEL WEIERSBYE-WITKOWSKI (PhD) Supervisor: Dr Colin Straker

  The effect of UVA light and light intensity on the response of Lagenaria sphaerica (Cucurbitaceae) to powdery mildew fungus (Sphaerotheca fuliginea) and elicitor treatment.

  This project is investigating the influence of blue-near UVA light and light intensity on resistant mechanisms in cucurbits. Physiological responses (photosynthesis, transpiration and respiration), biochemical responses (changes in levels of PR proteins and sugars) and elemental fluxes (nuclear microprobe measurements of changes in distribution of macro- and micro-elements) are being observed in both resistant and susceptible members of the group.

Further information

For further information on Mycological research in the Department of Botany and on opportunities for postgraduate studies in Mycology contact either Dr J Fletcher or Dr CJ Straker.