Phytoplasma diversity in natural habitats

Phytoplasmas, a group of plant-parasitic bacteria transmitted from plant to plant by sap sucking insects (Hemiptera, including leafhoppers, planthoppers and jumping plant lice), were previously known mainly because they cause severe diseases of cultivated crops. Recent screening of DNA samples from preserved museum specimens of hemipteran insects indicated that phytoplasmas are widespread in nature and that natural areas worldwide harbor many previously undocumented phytoplasma strains. This project aims to uncover the true diversity of phytoplasmas worldwide, reconstruct their evolutionary relationships, and document their associations with insects and plants by screening a large collection of insects preserved in a museum biorepository using next-generation DNA sequencing. The new data will help identify hotspots of phytoplasma diversity worldwide, clarify the extent to which phytoplasmas have affected the evolution of their host plants and insect vectors, and contribute to training of a new generation of experts on phytoplasma ecology, epidemiology and evolution. Emergence of new plant diseases may be driven by environmental change (including climate change) that triggers the colonization of managed habitats (e.g., croplands) by previously unknown disease agents from adjacent natural areas. Improved knowledge on the overall phytoplasma diversity in natural areas will greatly facilitate efforts to predict and manage new disease outbreaks.