Potato virus Y; the Andean connection

Area of Science:

• Plant Virology
• Molecular Phylogenetics
• Agricultural Science

Background:

• Potato virus Y (PVY) is a major pathogen of potatoes and solanaceous crops.
• Necrogenic PVY strains, emerging in the 1980s, represent the most significant viral threat to potato production.
• Understanding PVY's evolutionary history is crucial for disease management.

Purpose of the Study:

• To investigate the origin and evolutionary history of Potato virus Y (PVY).
• To analyze the phylodynamics of PVY, including its diversification and the emergence of necrogenic strains.
• To correlate PVY evolution with historical agricultural practices and human activities.

Main Methods:

• Genomic sequencing of 32 Peruvian PVY isolates.
• Phylogenetic analysis of 460 PVY genomic sequences, including 428 published sequences.
• Molecular dating of PVY diversification events.

Main Results:

• PVY originated in South America, coinciding with potato domestication.
• The current PVY population emerged around 156 CE, with significant diversification in the mid-19th century.
• Human activities, including trade and breeding post-Phytophthora infestans epidemics, heavily influenced PVY's spread and evolution, leading to damaging necrogenic strains.

Conclusions:

• Human activity has been the primary driver of PVY phylodynamics over the last two millennia.
• The introduction of PVY to Europe likely occurred in the 16th century.
• The emergence of diverse and damaging PVY strains is linked to historical agricultural practices and lack of quarantine measures.