Abstract
Various species of Euphorbia occur in South Africa, including herbaceous, succulent and woody types. The largest of the succulent Euphorbia spp. in South Africa is Euphorbia ingens. These trees have been dying at an alarming rate in the Limpopo province during the course of the last 15 years. Investigations into the possible causes of the death have included the possible role of fungal pathogens. Amongst the fungi isolated from diseased trees were species in the Botryosphaeriaceae. The aim of this study was to identify these fungi using morphology and DNA sequence data of two gene regions (TEF 1-α and ITS). Results showed that Lasiodiplodia theobromae and L. mahajangana were present, representing the first report of Lasiodiplodia species on a succulent Euphorbia species. Pathogenicity studies showed that these Lasiodiplodia species can cause infections on healthy E. ingens trees, implicating them as contributors to the decline of E. ingens.
| Original language | English |
|---|---|
| Pages (from-to) | 165-173 |
| Number of pages | 9 |
| Journal | Southern Forests |
| Volume | 73 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Sep 2011 |
Funding
Acknowledgements — We thank the Department of Science and Technology/National Research Foundation (DST/NRF) Centre of Excellence in Tree Health Biotechnology (CTHB) and the University of Pretoria, South Africa, for financial support, and Dr Jeff Garnas for assistance with statistical analysis. We also thank Mr Mark Howitt, Mrs Rentia Malan, Mr Keith Johnson, Mr Manie Elof, Mr Chris Richards, Ms Hermien Roux and Mr Alf Sephton for permission to undertake field studies. We also gratefully acknowledge the assistance of Dr Norbert Hahn with plant identifications and field work. The National Zoological Gardens (NZG) is thanked for permission to work on their property and for logistical support at Mokopane.
| Funders |
|---|
| University of Pretoria |
Keywords
- Botryosphaeriaceae
- candelabra trees
- climate change
- insect infestations
- tree diseases
