Start Date: Feb 26, 2008
End Date: Jan 19, 2011
A species and strain phylogeny for fungi causing diseases of alfalfa, specifically Stemphylim and Pleospora, will be developed based on strains from diverse hosts based sequences of multiple loci. The molecular phylogenies will be integrated with data that distinguish morphological characters to enable the production of keys to species. New and existing strains or pathotypes from alfalfa or its associated rotation crops and weed hosts will be characterized and integrated into updated phylogenetic frameworks. Once the molecular and morphological descriptions of new collections are complete, keys to groups of species will be prepared that can be used for the identification of species of Stemphylum and Pleospora. Closely related strains identified as single species groups will be analyzed for further molecular diversity using two approaches: DNA fingerprinting (AFLP), and a new multi-gene approach which will type specific sequences from multiple loci (MLST). Research will be developed to utilize resistant and susceptible M. truncatula lines models for functional genomic studies including research to map and identify resistance genes, determine mechanisms of defense, and investigate host-pathogen relationships. Cultivar selection will be based on the presence and range of highly desirable agronomic traits, including fall dormancy, genetic diversity, winter hardiness, yield, and a variety of growth habits. To determine the vulnerability of alfalfa to Stemphylium strains and species that cause disease in other crops, pathogens of alfalfa will be evaluated for virulence on M. sativa and M. truncatula cultivars selected for high and low susceptibility to leaf spot disease.