ESCA OF GRAPEVINES IN SOUTH AFRICA Presented by
ESCA OF GRAPEVINES IN SOUTH AFRICA Presented by Jan Booysen Chana-Lee White Francois Halleen and Lizel Mostert Department of Plant Pathology Faculty of Agriculture
What is Esca? • Affects trunk and arms of older grapevines • Disease complex producing overall syndrome • 2 distinct diseases • Wood rot • Brown wood streaking 2
History of Esca in South Africa • • 3 Little information on Esca Few incidences found Only symptoms observed Since 2001, Esca diseased vines have been collected and causal fungi isolated
In the field… 4
Symptoms: Leaves 5
Symptoms: Leaves 6
Symptoms: Berries 7
Symptoms: 8
Symptoms: Apoplexy 9
Aims and Current Study • Determine and characterize basidiomycetes involved • Identify other fungi involved • Botryosphaeriaceae, Phomopsis, Phaeoacremonium, Phaeomoniella • Geographical distribution of species 10
Isolations • Farms in the Western and Northern Cape visited • Isolations • Cultures selected 11
Distribution of esca diseased vines ZIMBABWE MOZAMBIQUE NORTHERN PROVINCE LIMPOPO BOTSWANA MPUMALANGA NORTH WEST GAUTENG SWAZILAND NAMIBIA KWAZULU-NATAL FREE STATE NORTHERN CAPE LESOTHO EASTERN CAPE WESTERN 12
Age of vines sampled 13
Young Esca • 2 -year-old vine from Paarl 14
Organisms Involved 16
Basidiocarps 17
Basidiomycetes characterization • 140 isolates used • Sequencing of ITS region using ITS 1 and ITS 4 • New species identification 18
Phylogram of ITS Heuristic search 1000 bootstrap Fomitiporia Innonotus Inocutis Unknown
Conclusions • Esca is widespread on grapevines in SA, occurring mostly on grapevines of 10 yrs and older • A species-complex of 7 Basidiomycete species • Predominant species: Inocutis sp. Fomitiporia sp. 20
Outcomes • Better understanding of Esca in South Africa • Aid in development of control strategies • Aid in developing early detection tools 21
Acknowledgements • NRF and Winetech for funding • Personnel at ARC-Nietvoorbji for technical support 22
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