Date and Time
Location
112 Buckhout Laboratory
The characterization of plant germplasm has tremendous potential to help address forthcoming challenges that the field of plant health is facing, such as climate change continuously modifying the regions of previously known disease occurrence. The worldwide trade of the plant genus Phlox represents a key revenue for the horticulture industry. However, Phlox species are highly susceptible to the fungal disease powdery mildew (PM), and infected materials shipping across borders accelerate the risk of disease spread. Through collaboration with laboratories in the U.S., we investigated the genotypic diversity of a PM population of isolates to better understand PM’s capacity to adapt to new environments and new resistant hosts. To do so, we first developed a set of laboratory tools to grow and study PM pathogens of Phlox in vitro, and then used multilocus sequence typing analysis and whole genome comparison to study the genetic structure of our population. Additionally, we explored Phlox germplasm diversity to identify the range of plant responses to PM infection in vitro by comparing the Area Under the Disease Progress Curve (AUDPC) and latency period of spore production across a combination of Phlox species and PM isolates. Our results showed a lack of genetic structure and low genetic diversity within the PM population examined. In contrast, we observed diverse phenotypic responses in the germplasm screening, which could be explained by the diversity of secreted proteins found across PM genomes. Our results also suggest the presence of qualitative and quantitative resistant traits in Phlox germplasm. This research explored the genome variation and evolutionary potential of Phlox PM pathogens to infer durability of host resistance, which are key tools to face plant health future challenges.