Dissecting Fusarium head blight resistance on wheat chromosome 4D

Hales, Benjamin (2019) Dissecting Fusarium head blight resistance on wheat chromosome 4D. Doctoral thesis, University of East Anglia.

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Abstract

Fusarium head blight (FHB) is a fungal disease of wheat and other cereal crops. It is responsible for grain yield and quality reductions, in addition to the accumulation of predominantly trichothecene mycotoxins in grain. The most important of these mycotoxins is deoxynivalenol (DON), which is harmful to human and animal consumers, in addition to acting as a virulence factor in wheat by promoting the spread of infection.
It has been shown previously that the short arm of chromosome 4D carries an FHB susceptibility factor. Chinese Spring cytogenetic material confirmed that the FHB susceptibility factor promotes the spread of the fungus independently of DON. Two resistance factors were also identified on 4D: a 4DS DON resistance factor and a 4DL Type I resistance factor. Genotyping and phenotyping of Chinese Spring terminal deletion lines refined the FHB susceptibility factor to a 31.7 Mbp interval containing 274 genes and the DON resistance interval was refined to 4.2 Mbp, containing 49 genes.
A deletion mapping approach, using a gamma-irradiated Paragon population, was used to further refine the position of the FHB susceptibility factor. Lines containing deletions across the remaining interval were identified using two successive markers screens, in addition to skim sequencing of a subset of the population. Disease phenotyping eliminated most of the FHB susceptibility interval, leaving three small intervals containing a total of 66 genes.
Functional annotation and gene expression data were used to interrogate the 4DS DON resistance interval, to identify potential candidates responsible for the DON resistance. DON application experiments were conducted on Cadenza TILLING mutants of two genes encoding aldo-keto reductases and on gamma-irradiated Paragon lines to refine the DON resistance interval. However, no change in DON susceptibility was observed in the lines, which prevented interval refinement.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Katherine Whittaker
Date Deposited: 14 Feb 2020 16:48
Last Modified: 14 Feb 2020 16:48
URI: https://ueaeprints.uea.ac.uk/id/eprint/74206
DOI:

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