Did Armillaria pathogens track their hosts in the National Botanic Garden, Zimbabwe?

2020| Luke Jimu, PhD, Bindura University of Science Education, Zimbabwe

The Kimmel International Grant will be used to provide information and solutions to tree health challenges in the National Herbarium and Botanic Garden in Harare, the capital city of Zimbabwe. The National Botanic Garden has an area of about 7 km2 and is home to over 1000 native and exotic plant species. About half of the garden is devoted to indigenous plants from Zimbabwe’s woodlands, including most of the 750 species found in the country. Other areas contain plants typical to the African continent including rare and endangered species, as well as exotics from South America, India, Australia and the Far East. It is therefore an area of recreational and tourism importance, receiving hundreds of visitors daily and is a centre for research and information on the indigenous plants of Zimbabwe. Recently, numerous dead and dying trees were observed on both native and exotic trees species in the Garden, threatening the existence of the trees and reducing the Garden’s utility value as a recreational area. The symptoms observed are consistent with those of root and stem rot caused by Armillaria pathogens. We hypothesize that 1) the pathogens causing root and stem rots in the Garden tracked their hosts from either the native forests in Zimbabwe or various localities globally where exotic tree species were imported from; 2) once introduced in the Garden, the pathogens adapted to infect closely related host trees and therefore expanded their host range. To test these hypotheses, we aim to extensively collect samples of Armillaria and other pathogens from native and non-native tree hosts in the Garden and identify those using morphology and DNA sequence data. We also aim to reveal the phylogenetic diversity of Armillaria in the Garden and to establish their relationships with those collected from all over the world. The information gathered will be useful in the identification and management of in the Garden and other similar Parks in Zimbabwe.

Year: 2020

Funding Duration: 1 year

Grant Program: Jack Kimmel International Grant

Grant Title: Did Armillaria pathogens track their hosts in the National Botanic Garden, Zimbabwe?

Researcher: Dr. Luke Jimu

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For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.