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02 August 2022 | Story Leonie Bolleurs | Photo Leonie Bolleurs
Alistair Naidoo, second-year master’s student in Conservation Genetics and full-time technician in the Department of Genetics; Prof Paul Grobler, Head of the Department of Genetics; Prof Gordon Luikart; and Hannah Janse van Vuuren, third-year master’s student in Conservation Genetics.

It is an important and exciting time to be doing research in conservation genetics. This is according to Prof Gordon Luikart, Professor of Conservation Ecology and Genetics at the Flathead Lake Bio Station at the University of Montana in the United States. 

Prof Luikart, whose primary research focus is the application of genetics to the conservation of natural and managed populations, recently delivered a lecture, The Expanding Role of Genetics/omics in Wildlife Research and Conservation, on the Bloemfontein Campus of the University of the Free State (UFS). The lecture, hosted by the Department of Genetics, was attended by a group of students and lecturers in conservation and a number of related fields. 

He is one of the leading scientists in the field of conservation genetics, including integration of genomics in conservation projects. He is also co-author of the textbook Conservation and the Genomics of populations – the current prescribed textbook for GENE3744.

Species threatened with extinction

In 2008, the International Union for Conservation of Nature (IUCN) stated that approximately 10-20% of all vertebrate and plant species are threatened with extinction over the next few decades. In 1984, American biologist Edward O Wilson also said that it will take millions of years to correct the ongoing loss of genetics and species diversity caused by the destruction of natural habitats. “This is the folly our descendants are least likely to forgive us.”

Prof Luikart is of the opinion that genetics has enormous potential to help manage wildlife and prevent extirpation. “My research works to realise this potential and help wildlife managers conserve populations and ecosystems,” he says. 

Conservation managers and biologists have understood the risks of inbreeding for more than 100 years. In his lecture, one of the aspects of genetic conservation he focused on, was the negative effects of inbreeding and how this can be reversed using genetic rescue. 

With the genetic rescue study, they found that the gene flow into recently isolated populations can increase individual fitness and population growth. He proposed that conservation managers should consider genetic principles and rescue as practical and important tools. 

Prof Luikart also provided a list of information that can be retrieved from molecular genetic data to help conservation managers. This includes intel on census and effective population size, gene flow and dispersal, local adaptation and selection, forensics, genetic identification and law enforcement, and disease ecology and transmission. 

Non-invasive genetic monitoring

In terms of detecting gene flow, he focused on a study about non-invasive genetic monitoring that was conducted in the Yellowstone Park. Prof Luikart and a group of students collected the shed hair and faeces of the grizzly bear, obtained from trees and hair traps, which were used as a source of DNA. 

They established, for instance, that inbreeding depression is more common and stronger than previously thought in natural populations. Genetic monitoring, using non-invasive methods as described, has been found to be an effective tool that conservation managers should consider for detecting inbreeding and loss of genome-wide variation.

His research on the bighorn sheep, the alpine ibex, and the black bear informed most of the findings he discussed during his lecture.

News Archive

Plant scientists address wheat rust diseases at SASPP congress
2015-02-02

Pictured from the left are: Prof Zakkie Pretorius, Dr Botma Visser and Howard Castelyn.
Photo: Supplied

In his research, Dr Botma Visser, researcher in the Department of Plant Sciences at the University of the Free State, highlighted the population dynamics of the stem rust fungus (Puccinia graminis f. sp. tritici) in Southern Africa. In recent years, two foreign stem rust races were introduced to South Africa, and a local virulence adaptation occurred in a third.

All of these races form part of the Ug99 group, a highly virulent collection of rust races endangering wheat production in many parts of the world. Despite the fact that half of the members of the Ug99 race group is prevalent in South Africa, Dr Visser’s work has clearly shown that Ug99 did not have its origin here. This emphasised the need to include neighbouring countries in the annual stem rust surveys, to proactively identify new races that could threaten local wheat production. In his research, Dr Visser also mentioned the way in which he has optimised modern molecular tools to accurately detect Ug99 isolates.

Dr Visser is one of three scientists from the Department of Plant Sciences that addressed delegates attending the biennial congress of the Southern African Society for Plant Pathology (SASPP) on the Bloemfontein Campus earlier this month on progress regarding research on wheat rust diseases conducted at the UFS.

Howard Castelyn, a PhD student in Plant Sciences, presented his research on quantifying fungal growth of the stem rust pathogen in wheat varieties displaying genetic resistance. This resistance, which is best expressed in adult plants, has the potential to remain durable in the presence of new rust variants. His presentation at the congress focused on optimising microscopic and molecular techniques to track fungal development in stem tissues of adult plants. These results now allow scientists to link rust infection levels and cellular responses with particular resistance genes expressed by the wheat plant, and contributing to the understanding and exploitation of durable resistance.

Prof Zakkie Pretorius presented his research, explaining how new genetic diversity for resistance to the stripe (yellow) rust fungus (Puccinia striiformis) is discovered, analysed and applied in South Africa. This research, conducted in collaboration with Dr Renée Prins and her team at CenGen, is unravelling the genetic basis of stripe rust resistance in a promising wheat line identified by Dr Willem Boshoff, a plant breeder at Pannar. The line and DNA markers to track the resistance genes will soon be introduced to South African wheat breeding programmes.

The rust research programme at the UFS contributes significantly to the successful control of these important crop diseases.

In addition to the contributions by the UFS, rust fungi featured prominently at the SASPP, with first reports of new diseases on sugar cane and Acacia and Eucalyptus trees in South Africa. A case study of the use of a rust fungus as a biological control agent for invasive plant species in the Western Cape, was also presented.

 

For more information or enquiries contact news@ufs.ac.za .

 

 

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