Understanding the Temporal Dynamics of Invasive Late Blight Populations in India for Improved Management Practices

Area of Science:

• Agricultural Science
• Microbial Ecology
• Genetics

Background:

• Phytophthora infestans causes devastating potato late blight epidemics globally.
• Understanding pathogen population dynamics is crucial for effective disease management.

Purpose of the Study:

• To investigate the population dynamics of Phytophthora infestans in the Indian subcontinent's potato agro-ecosystem.
• To analyze the genetic diversity and spread of invasive lineages over 14 years.

Main Methods:

• Utilized a comprehensive simple sequence repeat (SSR) allele dataset.
• Analyzed macroecological observations and microbial ecological principles.
• Compared Asian populations with European source populations.

Main Results:

• The invasive clonal lineage EU_13_A2 has dominated P. infestans populations across India, Bangladesh, and Pakistan for 14 years.
• Observed increasing subclonal variation, regional population structure within India, and evidence of local and cross-border migration.
• Identified genetic drift, between-season transmission of more pathogenic subclones, and displacement of some subclonal types.

Conclusions:

• The dominance of the EU_13_A2 lineage is potentially influenced by limited introduction of novel genotypes and the use of resistant potato cultivars.
• Findings provide critical insights for managing P. infestans in major global potato production regions.