Primary supervisor: Prof John Clarkson, University of Warwick

Non-academic partner: Dr Sara Jennings, Tozer Seeds

Project description

Background

Leafy green brassica vegetables such as collards, kale and cabbage are important crops worldwide with considerable health properties as they are a rich source of vitamins, minerals, fibre, and antioxidants which are known for their anti-cancer properties. However, these crops are highly susceptible to Fusarium wilt disease primarily caused by the plant pathogenic fungus Fusarium oxysporum f.sp. conglutinans (Foc). Foc is mainly a problem in warmer regions where brassicas are grown such as USA, Africa, China and southern Europe and results in yellowing, stunting and death of affected plants. Although resistance to Foc has been developed in cabbage, this was broken by the evolution of a new ‘race’ of the pathogen (race 2) which continues to cause disease on a range of brassica crops including collards and kale. However, there has been little research on genetic improvement of these particular crops despite their global importance, with the former being an important crop for African subsistence farmers.

Aims and Objectives

The main aim of this project is to investigate Fusarium resistance in collards / kale in collaboration with project partner Tozer Seeds. Objectives will include characterising Foc isolates and races isolated from different brassica vegetables, identifying new sources of resistance and beginning to understand the underlying mechanisms of pathogen virulence and resistance. As Foc also affects the model plant Arabidopsis, a close relative of collards, this presents the opportunity to screen A. thaliana accessions of wide geographic origin for resistance to Foc. Genetic mapping of Arabidopsis resistance to Foc will inform the identification of resistance in collards / kale. In parallel, we will combine the phenotypic characterisation of Foc isolates and races with sequence data in order to identify Foc virulence factors that can be used for diagnostics and identification of susceptibility genes that can be used in breeding programs.

Resources are already in place to achieve these aims and objectives. A large range of collard and kale accessions are available for resistance testing through Tozer Seeds and the UK Vegetable Genebank (located at Warwick) and we have also assembled a small Foc isolate collection and developed reproducible artificial inoculation procedures for the pathogen through an MSc project while a previous PhD project has begun to study the Foc-Arabidopsis interaction.

Candidates are encouraged to contact Prof John Clarkson to discuss the project before applying if they wish to.