Dr Nam Pham

CURRENT PROJECT

The project focuses on emerging tree diseases, which have expanded their host and geographic range, increased in severity, or are newly discovered. Such diseases have been reported in both natural woody ecosystems and planted forests, reshaping forests globally.

The scientific community recognizes emerging diseases as a significant aspect of global change, posing a primary threat to forest ecosystems. Factors contributing to the emergence include the unintentional movement of species, climate change, and changes in land use and forest management.

Commercial plantation forestry in tropical and Southern Hemisphere regions is extremely vulnerable to emerging diseases, jeopardizing the sustainability of these forests. There is thus an urgent need for research, including the use of genetic and genomic tools, to understand the biology, ecology, and evolution of tree pathogens, providing insights for developing effective disease management strategies.

>More information: 10.1146/annurev-phyto-121823-030316

PH.D. PROJECT

In 2018, I started my Ph.D. in Plant Pathology as a member of RGE-FABI Tree Health Programme (RGE-FABI THP) and T ree Protection Co-operative Programme (TPCP).

For my Ph.D., I investigated a serious disease recently named as Eucalyptus scab and shoot malformation. The disease was first observed in North Sumatra, Indonesia in 2014. However, the causal agent was discovered only recently as a novel species of Elsinoe. The name of the pathogen is derived from the Latin word “necatrix” (killer, murderess) to refer to the destructive impact that the disease has on its Eucalyptus hosts.

The disease is characterized by black necrotic spots that initially appear on young leaves and petioles, which become scab‐like as the lesions age. Infected trees respond to infection by producing shoots with small leaves that commonly appear feathered. Severely affected clones usually die after a number of successive infection cycles, generally over a period of 2–3 years.

The origin of Elsinoe necatrixis unknown, but evidence suggests that this is likely an area where  species are native. The pathogen would then have been accidentally introduced into North Sumatra where it has encountered susceptible host trees and an environment conducive to infection. In this regard, it should be considered as a high-risk pathogen and efforts should be made to prevent its spread to new environments.