Scleroderris canker of pine and spruce (Gremmeniella abietina), lower branches infected with Scleroderris canker.
Image Credit: USDA Forest Service - North Central Research Station , USDA Forest Service, Bugwood.org.
Licensed under a Creative Commons Attribution 3.0 License.

Scleroderris canker, caused by the Ascomycete Gremmeniella abietina, is a disease of conifers that can cause severe defoliation and lethal stem cankers. It comprises multiple races that differ in their pathogenicity and epidemiology¹. The North American race, unlike the European race, reproduces both sexually and asexually. The North American race is native to North America while the European race was introduced to North America in the 1950s and has since been regulated by quarantines in Canada and the USA. Both races can cause seedling mortality and the European race can also cause severe outbreak and mortality on large pines in North America and Europe. One of the challenges of preventing the spread of these pathogens is that they can have endophytic stages and therefore be transmitted on asymptomatic seedlings. Sequencing the genomes of these pathogens will greatly accelerate our understanding of their epidemiology and biology and will help develop tools to better detect, identify and monitor outbreaks. The genome sequencing of Gremmeniella abietina North American race is part of a larger effort, the Pathobiome Database For Bioenergy Trees Project that aims to sequence the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. This data will be used to create a database that will help the development of tools for the detection, monitoring and surveillance of pathogens in these economically and ecologically important trees.

References:

1. Hamelin, R.C., Ouellette, G.B. and Bernier, L., 1993. Identification of Gremmeniella abietina races with random amplified polymorphic DNA markers. Applied and Environmental Microbiology, 59(6), pp.1752-1755.