Genomics of the Fusiform Rust and Brown Spot Needle Blight Systems

ABSTRACT University of Kentucky – Forest Service SRS Partnership Agreement, Research Joint Venture: Genomics of the Fusiform Rust and Brown Spot Needle Blight Systems Purpose: Apply novel comparative genomics methods to study the origin of the Lecanosticta acicula outbreak on Loblolly pineand compare historic and contemporary variation in the fusiform rust pathogen (Cronartium quercuum f.sp. fusiforme) with implications for resistance breeding and management. Statement of Mutual Interest and Mutual Benefit: Dr. Mark Farman, University of Kentucky, has developed novel methods and software tools that yield critical insights into fungal population structure that are overlooked by the other tools widely in use. These tools will be used to test the hypothesis that the recent brown spot outbreak on loblolly work is caused by a novel Lecanosticta acicula population derived through admixture. At the same time, these tools will be used to characterize genome-wide variation in the pathogen population. Farman was a pioneer in the use of genetic markers for map-based cloning of fungal avirulence genes and will leverage his experience in whole-genome analysis to identify the Avr1 avirulence gene corresponding to the pine resistance gene, Fr1. This study will increase our understanding of the Fr/Avr gene system, their prevalence over space and time, and inform management strategies. These projects contribute to the missions of both organizations by continuing the development and validation of new comparative genomics methods, investigating the origins of the L. acicula outbreak on Loblolly pine, increasing our understanding of the fusiform rust system,guiding resistance development and deployment, and helping to maintain sustainable and productive forests.