Association Analysis Identifies Melampsora ×columbiana Poplar Leaf Rust Resistance SNPs

Jonathan La Mantia, Jaroslav Klápště, Yousry A. El-Kassaby, Shofiul Azam, Robert D. Guy, Carl J. Douglas, Shawn D. Mansfield, Richard Hamelin, Ivan Baxter
2013 PLoS ONE  
Populus species are currently being domesticated through intensive time-and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-racespecific loci.
more » ... the presented study, area under the disease progress curve was calculated from natural infection of Melampsora 6columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P,0.05) with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-racespecificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca 2+ /calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism.
doi:10.1371/journal.pone.0078423 pmid:24236018 pmcid:PMC3827267 fatcat:i7ujepn6gze2lge5t4bx2mutiu