Armillaria fumosa, collected from a home garden in a suburb of Brisbane Australia, June 5, 2011 [Photo credit: Kenneth Cowell]

Armillaria fumosa, collected from a home garden in a suburb of Brisbane Australia, June 5, 2011 [Photo credit: Kenneth Cowell]

In the “1KFG: Deep Sequencing of Ecologically-relevant Dikarya” project (CSP1974), we aim to sequence additional sampling of genomic diversity within keystone lineages of plant-interacting fungi and saprophytic fungi that are of special ecological importance for understanding terrestrial ecosystems. In addition, comparative genome analysis with saprotrophic, mycorrhizal and pathogenic fungi will provide new insights into the specific and conserved adaptations associated with each fungal lifestyle.

Armillaria fumosa CBS 122221

Members of the genus Armillaria belong to the Physalacriaceae, a highly diverse family in the Agaricales containing wood decayers and devastating tree pathogens. They cause shoestring root rot, which leads to significant losses in woody areas, including forests, parks or vineyards, among others, mostly in the temperate zone. The infection is usually characterized by presence of rhizomorphs and mycelial mats between the bark and cambium layer of the host root. Rhizomorphs are shoestring-like multicellular structures, which are analogous to plant roots in appearance and forage for food by spreading inside the soil. Armillaria spp. produce macroscopic fruiting bodies that are edible and known as honey mushrooms. Many existing individuals of Armillaria are believed to be the largest and oldest terrestrial organisms known on Earth.

We aim to sequence the genomes of several Armillaria strains representing both aggressive pathogens and white-rot saprotrophs. This will allow us to gain insights into the evolution of pathogenicity and the mechanisms of interaction between Armillaria and their host trees. It will further help in understanding the biology of these species, including their strategies for host invasion, for wood decay, and the development of rhizomorphs and fruiting bodies. We hope these resources will open the door for developing efficient management strategies for limiting the spread and damage to forest ecosystems.

Armillaria fumosa (Kile and Watling)¹ has been recorded from several eucalyptus forests in Australia, New Zealand and Indo-Malaysia. Not much is known about its pathogenicity potential, however it is believed to be a non-virulent species^2,3. It grows as clumps of 5-20 fruiting bodies on stem bases and roots of Eucalyptus obliqua. The mature fruiting body is around 9-10 cm high. Pileus ranges from being convex to funnel-shaped, has pale yellow-brown margins and a distinct grey color towards the center. 

Researchers who wish to publish analyses using data from unpublished CSP genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the CSP master paper(s).