Venturia populina (Vuill.) Fabric. (Fungi, Ascomycota, Pezizomycotina, Dothideomycetes) is a pathogen that causes shoot blight and shepherd’s crooks on poplar, aspen and cottonwood. It has been reported in North America, Europe and Asia. The spores of this fungus overwinter in fallen leaves and in diseased stems and twigs. The pathogen infects newly expanding leaves and shoots, and spreads down through the succulent new shoot, which blackens and curls to resemble a shepherd's crook. Death of new shoots causes distorted new growth. This disease is most severe in young stands, and has the greatest impact in intensively managed plantations. Attacks by pathogens represent one of the most important threats to the sustainable growth of bioenergy trees in plantations. Outbreak prevention depends largely on a better understanding of how pathogens infect trees so that resistance can be developed and on early detection, monitoring and surveillance to prevent spread. Since pathogens of poplars and pines tend to track their hosts worldwide, we must do a better job at detection and surveillance. This can be challenging since pathogens can remain dormant or have endophytic stages in the host tissues. The genome sequencing of Venturia populina is part of a larger effort, the "Pathobiome database for bioenergy trees project", that aims at sequencing the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. By sequencing and comparing the genomes of the most important pathogens of poplars and pines, we plan to create a database that will be used to develop tools for the detection, monitoring, and surveillance of pathogens in these economically and ecologically important trees.
