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Plant Sciences graduate contributes technique to manage stem rust

08 October 2020 | Story Leonie Bolleurs | Photo Supplied

Dr Cornel Bender received her PhD qualification at the virtual graduation ceremonies in October. The title of her thesis is: Stem rust resistance in South African wheat and triticale.

The rapid distribution of disease-causing organisms such as Ug99, a wheat stem-rust pathotype, pointed out just how vulnerable global cereal production is to disease outbreaks.

These cereals include wheat, barley, rye, oats, triticale, rice, maize, and millet and are one of the most important food sources for human consumption.

According to Dr Cornel Bender, the projected world population of 10 billion in 2057 requires a growth of more than 40% in cereal production. Wheat is grown on more hectares than any other cereal and is one of the most important sources of calories for humans. However, the growth rate of wheat yields has declined from the 1960s to the 1990s. Therefore, it is essential to increase global wheat production.

“With the regular appearance of more aggressive stem rust pathotypes in South Africa, there is a constant need to discover new sources of resistance, understand the genetic base of presently deployed sources in wheat, triticale and barley cultivars, and to manipulate the deployment of resistant sources through a more sustainable approach,” says Dr Bender.

Her PhD thesis, titled: Stem rust resistance in South African wheat and triticale, includes various fundamental aspects for the effective management of stem rust in South Africa.

Dr Bender is a Professional Officer in the Division of Plant Pathology in the Department of Plant Sciences, who received her PhD at the virtual graduation ceremonies in October.

Innovative and cost effective

Her promotors, Prof Zakkie Pretorius, Research Fellow, and Dr Willem Boshoff, Senior Lecturer in the Department of Plant Sciences, believe that she used an innovative approach to develop a cost-effective phenotyping method to select for more durable resistance types in a controlled greenhouse environment.

“In the past, results obtained from field trials used to assess adult plants for stem-rust resistance, were often influenced by abiotic factors, were seasonable in nature, expensive, and time consuming; therefore, the development of a dependable greenhouse screening system provides an important additional instrument for rust research,” says Dr Bender.

She adds that the greenhouse technique is used worldwide to screen for adult plant resistance and contribute to save time and money.

Broadening our knowledge

“Inheritance studies were undertaken to determine the genetic base of stem-rust resistance in selected South African wheat and triticale cultivars (developed from wheat/rye crosses) through seedling analysis as well as greenhouse and fieldwork,” she says.

Dr Bender believes the use and development of different resistance screening methods, the elucidation of host genetics, as well as the use of histological and microscopic methods to study early resistance responses, broaden our knowledge and understanding of stem-rust resistance in South African wheat and triticale cultivars.

Ultimately, rust researchers, grain producers, and also the general public – through access to their daily bread – will benefit from her study.

News Archive

Death may come in adorable little packages

2015-03-23

The main host of the Lassa virus is the Natal Mulimammate mouse.

Photo: Supplied

Postdoctoral researcher, Abdon Atangana, of the Institute for Groundwater Studies at the university recently published an article online about the Lassa Haemorrhagic fever in the Natural Computing Applications Forum. In addition to the terminal transmissible sickness recognised as Ebola haemorrhagic fever, there is another strain called Lassa haemorrhagic fever.

The disease is classified under the arenaviridae virus family. The first outbreaks of the disease were observed in Nigeria, Liberia, Sierra Leone, and the Central African Republic. However, it was first described in 1969 in the town of Lassa, in Borno State, Nigeria.

The main host of the Lassa virus is the Natal Mulimammate mouse, an animal indigenous to most of Sub-Saharan Africa. The contamination in humans characteristically takes place through exposure to animal excrement through the respiratory or gastrointestinal tracts.

Mouthfuls of air containing tiny particle of infective material are understood to be the most noteworthy way of exposure. It is also possible to acquire the infection through broken skin or mucous membranes that are directly exposed to the infective material.

“The aim of my research was to propose a novel mathematical equation used to describe the spread of the illness amongst pregnant women in West Africa. To achieve this, I used my newly-proposed derivative with fractional order called beta-derivative. Since none of the commonly used integral transform could be used to derive the solution of the proposed model, I proposed a new integral transform called Atangana-Transform, and used it, together with some iterative technique, to derive the solution of the model.

“My numerical simulations show that the disease is as deadly amongst pregnant women as Ebola,” Abdon said.

Abdon’s research was submitted to one of Springer’s top-tier journals with an impact factor 1.78. The paper was accepted and published February 2015.