Prof Liezel Herselman, Academic Head of the
Department of Plant Sciences at the University of the Free State (UFS),) delivered her inaugural lecture on the Bloemfontein Campus this week (24 March 2022). The theme of the lecture was the ongoing battle against destructive cereal killers.
With 28 years of extensive experience as a researcher, her work focuses on marker-assisted disease resistance breeding in wheat within a South African context. When she joined the UFS in 2004, Prof Herselman decided to apply her research expertise in marker-assisted breeding to the problems faced by wheat producers in the Free State and Northern Cape. The Free State is one of the major dryland wheat production areas in South Africa, while irrigation wheat is produced along the major rivers in the Northern Cape.
Protection against fungal diseases
Concentrating specifically on Fusarium head blight (or wheat scab) and three rust diseases – leaf rust, stem rust, and stripe rust – she has done work to provide wheat plants with ‘tools’ to protect themselves against these fungal diseases.
According to Prof Herselman, there are many genes available in different wheat genotypes and related grass species that provide excellent protection against various races of these diseases. “Some of these genes provide protection or resistance from the seedling stage, while others provide resistance at the adult plant stage. We are thus aiming to combine as many of these genes as possible into a single wheat cultivar, without compromising yield and bread-making quality.”
She says the genes are combined by making crosses between resistant and susceptible cultivars or lines. Conventionally, through a time-consuming process, the incorporation of these genes is tested in the greenhouse and field by infecting plants with the disease to see which plants are resistant and which are not.
They can, however, follow the transfer of these genes to newly developed lines by applying molecular markers. Prof Herselman explains: “A molecular marker is a genomic fragment linked to the gene, which we can follow in the offspring we create from the crosses using different DNA techniques in the laboratory. This enables us to select new wheat lines that contain the highest number of resistance genes. The identified best lines are then used in further crosses and/or released as pre-breeding lines to commercial wheat breeding companies.”
Impact on food security
Her research has an impact on society by providing food security to both commercial and small-scale producers, as well as the end users of wheat (people buying bread and other wheat products). As researcher, it is also important for her to send out students to the workplace who can continue with this task in future.
Prof Herselman believes that when cultivars with fungal-disease tolerance or resistance are released and used by producers, it not only reduces the cost of spraying against diseases, but also increases yields by protecting the crop against fungal diseases. “We live in a world where the population is increasing daily, but land available for agriculture is not increasing and some areas are even lost due to urban development. Increasing yield in available production areas will thus have a positive impact on food security,” she says.
Besides contributing to the country’s food security, she takes pleasure in every aspect of her work. Although she misses the hands-on part of the work as academic head of the department and getting her hands dirty, she still enjoys managing the different research projects (from the conceptualisation phase to data analysis and publishing of results). The part she loves the most is to see the growth in her postgraduate students – from the moment they enter the laboratory for the first time until the day they walk out of the laboratory with their degrees.
“It adds purpose to my life knowing that I have made a difference in a student’s life and equipped him or her with the necessary tools to be successful in the marketplace. Being able to share your knowledge is a gift, but with that gift comes a lot of responsibility as well. I am, however, up for the challenge,” concludes Prof Herselman.