Project Reference: ICS27-NIA-LB1

Project title: The potential of durum wheat to deliver usable sources of ergot resistance

Project Outline

Ergot (Claviceps purpurea; Cp) is a fungal disease of cereal flowers, replacing the seed with an alkaloid containing sclerotia. Infected flowers produce honeydew, a sugary solution containing asexual spores. Most sources of ergot resistance are partial, the one exception being QCp.aafc.DH-2A, identified in the durum wheat Greenshank, that reduced honeydew by 90% and halved sclerotia weight (https://doi.org/10.1007/s00122-020-03561-9). Ergot has increased on UK farms due to the adoption of Regenerative Farming practices, poor weed control and the absence of effective fungicide regimes.

Aim: To explore wheat gene pools for ergot resistance, genetically defining resistance loci. Identification of the gene/s responsible for QCp.aafc.DH-2A will be a first, advancing our understanding of the biological mechanisms restricting Cp infection. 

At Niab we have developed Synthetic Hexaploid Wheat (SHW) populations by crossing 15 tetraploid (Triticum turgidum) with 47 diploid (Aegilops tauschii) wheats, including Greenshank. These SHW have been backcrossed to Paragon, generating wheat chromosome segment substitution lines (CSSLs). Greenshank SHW x Paragon BC1F5 populations have been genotyped using the 35K Axion SNP array, enabling us to characterise the genomic region containing QCp.aafc.DH-2A.

Obj. (1) Identify and characterise new ergot resistance. 

Screen T. turgidum, Ae. tauschii, SHW and CSSL for ergot resistance by hand-inoculating individual flowers with Cp, assessing honeydew levels, sclerotia size and weight. Working with DSV UK Ltd, KASP markers will be developed for these resistance regions.

Obj. (2) Identify the gene/s responsible for QCp.aafc.DH-2A. 

QCp.aafc.DH-2A spans 17.5 Mb (telomeric end of 2AL) incorporating 277 predicted genes, of which 14 are up-regulated by Cp. These candidates will be examined to determine their role in ergot resistance, using gene network co-expression analysis, TILLING to identify mutations and CRISPR to knock-out gene function. 

Principal Supervisor

Dr Lesley Boyd

Email address: lesley.boyd@niab.com

Department / Partner Institute: NIAB - Crop Pathology

Website: https://www.niab.com/about/people/dr-lesley-boyd

Industrial Partner

DSV UK Ltd

BBSRC strategic theme

Bioscience for sustainable agriculture and food