Reference collections are invaluable assets for the scientific, historical, and geographical study of plants, fungi, and plant pathogens. These repositories preserve specimens that serve as a lasting record of a species' occurrence in a specific time and place. New species are formally recognized by linking them to these specimens, known as type specimens. When taxonomic revisions arise from new evidence or discoveries, reference to the type specimen helps validate these changes. Reference collections are the foundation of our understanding of plant and pathogen classification, playing a crucial role in documenting and decoding the world’s biodiversity.
In the past decade, molecular techniques for investigating herbarium specimens have gained traction. Yet, fungal obligate biotrophic pathogens such as powdery mildews remained largely unexplored in next-generation sequencing (NGS) from reference collections. To bridge this knowledge gap, a PhD project was initiated with the goal of developing and validating molecular methods to unlock the genetic information stored in powdery mildew specimens from the Victorian Plant Pathogen Reference Collection (VPRI).
Through this PhD research new molecular protocols were implemented, enabling next-generation sequencing (NGS) data to be generated from powdery mildew specimens as old as 130 years. This breakthrough resolved long-standing powdery mildew taxonomic questions within the Australian horticultural industry, led to the discovery of a species previously unknown to science, and laid the foundation for future research of unculturable specimens from the VPRI.