EFS12- Book of abstracts - Contact

SESSION 4: GENETICS OF HOSTS – PLANT RESISTANCE TO FUSARIUM,
VARIETY DEVELOPMENT
P92 - Forthcoming development of diverse FHB and
DON resistant wheat in South Africa
S. Sydenham, C. De Villiers
ARC-Small Grain Institute, Bethlehem, Free State Province, South Africa, Private Bag X29, 9701
E-mail: sydenhams@arc.agric.za
In South Africa (SA) Fusarium head blight (FHB) has the potential to become an
epidemic on spring irrigation wheat under favourable conditions. Furthermore,
there are no moderate to highly tolerable FHB wheat varieties commercially
available in SA yet. Additionally, no fungicide is officially registered for the control
of FHB on wheat. Of major concern is the fact that deoxynivalenol (DON)
mycotoxin levels in wheat grain are not officially monitored as there is no
legislation or guidance level in place.
To avoid continual dependence on Sumai-3 based resistance, FHB nurseries and
novel resistant wheat sources are imported annually, diversifying the available
FHB resistance gene pool. Imported resistant donors/nurseries are screened by
the point inoculation method in the glasshouse and are further characterised with
targeted FHB resistance linked SSR markers. Only novel verified FHB resistant
donor sources are selected to be used further in variety development. Targeted
directional crosses for two focused programmes (one backcross focused and
other gene stacking focused) are carried out in the glasshouse based on
phenotypic and molecular data. Field trials of parental resistant donors and
developed material will be planted in a honey-comb design and artificially
inoculated (grain and liquid inoculum) under irrigation. Superior performing FHB
resistant entries will be selected based on glasshouse data, field trial performance
and molecular marker data.
Objective of this study is to develop diverse Fusarium head blight and DON
resistant adapted wheat germplasm by using a combined approach of phenotypic
screening and marker-assisted selection. The ultimate goal is to successfully
pyramid or stack a number of FHB QTL/genes from diverse donor sources into
top performing wheat cultivars that are well adapted to South African irrigation
areas, with increased FHB resistance, reduced DON accumulation, reduced
kernel damage and reduced yield loss.
Intended outcomes include both the successful commercial release of FHB
resistant cultivars as well as a series of FHB resistant germplasm registrations.
Keywords: Fusarium Head Blight, gene pyramiding, SSR markers, resistance
QTL/gene
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