Breeding crops that are more disease resistant

Despite the extremely high yields that can be realised for cereal crops in Ireland, our cool wet summers also present a significant challenge for growing cereal crops Two of the most significant cereal diseases in Ireland are Septoria tritici blotch (STB) in winter wheat, and Fusarium head blight (FHB) in all cereals (wheat, barley and oats). A major problem in achieving the goal of developing varieties with increased resistance to these diseases is the simple fact that Ireland has no indigenous cereal breeding programmes. Consequently, we rely on varieties bred specifically for Great Britain and northern Europe. While varieties from such breeding programmes have many of the required agronomic properties for production in Ireland, STB (and to some extent) FHB are not necessarily the main disease pressure in the primary target regions for these varieties, and consequently, few varieties exhibiting high levels of resistance to these diseases are available.

While it may not be feasible to re-establish commercial scale breeding programmes for cereals in Ireland, an alternative approach is to develop tools that would enable current (UK and European) cereal breeders supplying the Irish market to select for resistance to these diseases more efficiently. VICCI will identify germplasm that has resistant phenotypes of relevance, and (depending on the specific source) this germplasm may be of direct use as potential parental material in breeding programmes.

VICCI also aims to develop a better understanding of genetic and metabolic responses of wheat to STB and wheat, barley and oats to FHB, and to exploit this knowledge to lead to the development of resistant phenotypes to both diseases in breeding programmes. VICCI partners are utilising transcriptomic and metabolic profiling of germplasm to identify pathways and specific genes conferring resistance to STB and FHB in cereal germplasm. Candidate genes will subsequently be validated using a mixture of reverse genetics strategies (overexpression, VIGS/VOX, CRISPR and TILLING) in order to identify genes with the greatest potential for generating novel genotypes and/or genetic markers. Direct interaction with commercial breeders will facilitate the identification and exploitation of the most promising candidates via marker assisted selection and other biotechnology-based genetic improvement strategies.