TECHNICAL SESSION: Tree Pathology
Association mapping and transcriptomic analyses reveal genes associated with resistance of Populus trichocarpa to Septoria leaf spot
Susanna Kerio - Department of Botany and Plant Pathology, Oregon State University. Ryan Lenz- Department of Botany and Plant Pathology, Oregon State University, Wellington Muchero- Oak Ridge National Laboratory, Jared LeBoldus- Oregon State University, Kelsey Sondreli- Department of Botany and Plant Pathology, Oregon State University, K
The ascomycete Sphaerulina musiva causes Septoria leaf spot and stem canker of Populus and is the most serious pathogen of poplars in North America. Knowledge of genes associated with resistance to leaf spot can be used to select for resistant planting stock. We inoculated and phenotyped 540 distinct Populus trichocarpa genotypes in a randomized complete block design to identify loci associated with leaf spot resistance. The leaf spot phenotypes were recorded after two weeks and correlated in a genome-wide association analysis to 8,253,066 SNPs and insertion/deletions. Subsequently, RNAseq was applied to study gene expression in a subset of resistant and susceptible genotypes. We will report the heritability estimates for leaf spot resistance, genes associated with phenotypic variation, and patterns of gene expression in response to S. musiva inoculation. The significance of the results for resistance breeding and management of foliar diseases in poplar plantations will be discussed.