Development of a model system comprising Populus as a model tree and Colletotrichum gloeosporioides as a model pathogen for studying host-pathogen interactions

To develop a model system for studying host tree-fungal pathogen interactions, we focused on Populus as a model tree and the fungus Colletotrichum gloeosporioides as a model pathogen. Although hybrid Populus is currently planted worldwide for biomass production and other purposes, the hybrid often lacks the tolerance of native species to cold, drought, and disease. Populus diseases have increased with the rapid development of Populus plantations worldwide. To investigate the susceptibility of hybrid aspen plants to the fungal pathogen Colletotrichum, which has a wide range of hosts, hybrid aspen plants were inoculated with Colletotrichum species such as C. dematium, C. destructivum, C. gloeosporioides, C. higginsianum, and C. orbiculare. C. gloeosporioides strains isolated from strawberry plants could infect hybrid aspen. These results indicate that monoculture of hybrid Populus may be potentially susceptible to local pathogens. The experimental system using hybrid aspen and C. gloeosporioides presented here will bring a lot of fruitful information, as first model system of host tree-fungal pathogen interactions.