Abstract
The overall aim of the fellowship is to analyse the molecular evolution of a family of genes in fungi, which cause powdery mildew diseases of plants. Avirulence genes elicit host defences in gene-for-gene interactions with plants. The family to be studied is related to the Avrk1 gene in the barley mildew, Blumeria graminis f.sp. hordei. The specific objectives are: 1. To research the evolution of members of the Avrk1-like gene family in diverse isolates of B. graminis hordei. This will identify elements of the genes, which are: (a) conserved and may be required for pathogenicity, (b) subject to diversifying selection, so probably involved in gene-for-gene interactions, (c) not essential for pathogenicity. The work will involve culturing of B. graminis isolate s, cloning Avrk1-like fragments by homology with Avrk1, and sequencing of Avrk1-like genes, followed by phylogenetic analysis of sequences. 2. To examine host-specialisation of wheat and barley mildew by investigating the divergence of members of the Avrk1 -like family, and to research the distribution of Avrk1-like genes in diverse mildew pathogens of dicot plants. The methods used will be similar to those in Objective 1. 3. To analyse the association of Avrk1-like genes with avirulences, to identify Avrk1-like sequences as candidate avirulence genes. This will involve crossing B. graminis isolates, extracting ascospore progeny, and analysis of avirulence on a differential set of barley varieties. Avrk1 homologues will be analysed for sequence variation between the parents of the cross and polymorphisms mapped in the progeny to investigate their linkage to avirulence loci. The fellowship will provide Ms Sacristan with expert training in: 1. Phylogenetic methods applied to evolution of DNA sequences (Objective s 1 and 2); 2. Fungal genetics and genetic analysis (Objective 3); 3. Advanced methods of molecular marker analysis (Objectives 1 and 3); 4. Fungal plant pathology and mycological methods (all 3 Objectives).
Europe