Mr Godfrey Kgatle
The quantity of the Sunflower (Helianthus annuus L.) oil represents about 82% of all edible oil produced in South Africa. The crop is propagated by seeds. It is recorded that more than 24 fungal speciesare seed-borne in the crop. Among the predominant seed-borne pathogens are Alternaria alternata. Seed infection with A. alternata causes biodetorioration and reduction in germination in the seeds. At the University of Pretoria Seed Pathology labs, various Alternaria speices such A. alternata, A. tenuissima and A. helianthicola have been consistently isolated from sunflower seeds of different cultivars received from the major sunflower growing areas of South Africa since 2010. These Alternaria species have been isolated from leaves sunflower.
The focus of my masters study was on the 1.) Identification of Alternaria spp. isolated from Helianthus annuus L. (sunflower) seeds and leaves using morphological and molecular techniques 2.) Etiology of Alternaria spp. of sunflower 3.) Evaluating the seed vigor and health of H. annuus. My PhD follows up the masters studies by further studying the infection processes of Alternaria spp. using scanning electron and light microscopy, determining the source of inoculum of Alternaria in the field and also evaluating fungicides and biocontrol agents as a possible control mechanism for Alternaria blight
· To determine the distribution of Alternaria blight by surveying the major sunflower growing areas in South Africa for Alternaria leaf spot (Surveying and sample collection will be done for 2-3 years, from 2014-2016).
· To identify the causal agents of Alternaria blight based on morphology, toxin profiling and molecular techniques (Samples that will be collected during the survey will then be identified: 2014-2016).
· To determine the seed health and seed vigour of sunflower seed lots (Untreated seeds will be collected from sunflower growing areas to conduct the respective seed tests from 2014 and 2015).
· To determine location of infection in the seed by using a seed component test and Real-time PCR (this will be done using the collected seeds: 2014-2015).
· To determine the source of Alternaria species inoculum on sunflower fields (during the course of 2014 and 2015).
· To determine the susceptibility/resistance of different cultivars to Alternaria blight (during the course of 2014 and 2015).
· Microscopy (EM) study of infection process, bio-control and Alternaria interaction.
· To determine bio-control and chemical control measures (during the course of 2014 and 2015 as the control agents need to be tested for reproducibility).
Supervisor: Prof. Terry Aveling
Co-supervisor: Prof Brad Flett (ARC-GCI)
Dr. Mariette Truter (ARC-PPRI)
Tel: 012 420 5351