Page 64 - University of Pretoria RESEARCH REVIEW 2018

Identifying fungal pathogens and pathways
Irene Barnes, Department of Biochemistry, Genetics and Microbiology, and FABI
Tree diseases are growing in importance globally. Characterising and describing the biodiversity, host ranges and geographic distributions of the different fungal pathogens that cause these diseases are critical in stemming this tide.
trees such as Eucalyptus, which are important to forestry in South Africa.
The spread of pine needle diseases globally is of special interest to
Dr Barnes and her collaborators. One of the objectives of their research is to understand the threat pathogens causing these diseases pose to the South African pine industry. Following this area of interest, Dr Barnes has made extensive collections in Central America – the source of some of our pine species planted in South Africa – to determine the biodiversity of these pine fungi. This work has led to the discovery and description of several new fungal species.
Dr Barnes has also been involved in or led the production of the most comprehensive current reviews
on important pathogens of pines, including Lecanosticta acicola and two Dothistroma sp. Studies are being conducted with scientists from over 40 countries, on all continents where the pathogens occur, to produce detailed distribution maps, and to characterise the global population genetic structure and diversity of these pathogens.
Dr Irene Barnes, a senior lecturer at FABI and one of the research leaders in the Tree Protection Co-operative Programme, focuses her research on fungal pathogens that cause diseases on native and non-native forest tree species. Over the past few years, together with her students and colleagues in FABI, she has developed molecular diagnostic tools that can be used accurately and effectively to identify species of fungi that cause tree diseases. They have also generated markers that can be used to study the population genetics of these important pathogens so as to
understand how they spread.
Recently, Hawaii has been experiencing a devastating disease epidemic called rapid `ōhi`a
death (ROD) where hundreds of thousands of their native tree species, Metrosideros polymorpha, have been dying. Dr Barnes, together with colleagues in various parts of the world, discovered that the disease
is caused by two fungal species. These Ceratocystis species, both
new to science, were described and given Hawaiian names. The findings were published in Persoonia in 2018. Population genetic analyses showed these species were most likely newly introduced onto the Island although their origin remains a mystery. Knowledge of the pathogens and their biology is contributing to efforts to manage this serious disease.
This work is also contributing to
the growing knowledge of other Ceratocystis diseases important to
Red Band Needle Blight disease.
Dr Irene Barnes received the internationally acclaimed 2018 Ethel Mary Doidge Medal for outstanding early career research in mycology by the International Mycological Association. This Africa-wide award is named after the famous plant pathologist Ethel Doidge (1887- 1965), who was the first female to receive a doctorate in South Africa. Barnes was also named the first runner-up in the Distinguished Young Women Researchers category of the Department of Science and Technology’s Women in Science Awards.
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