Intraspecific Diversity of Pratylenchus neglectus Associated with Cereal Root Lesion Nematode Disease

Abstract

Intraspecific diversity of Pratylenchus neglectus associated with cereal root lesion nematode disease was investigated to understand population variability, host adaptation, and implications for disease severity in cereal production systems. Field samples were collected from major cereal-growing regions showing typical root lesion symptoms, including cortical necrosis, reduced root biomass, and stunted plant growth. Nematodes were extracted from infected roots and characterized using morphological traits of adult females and juveniles, complemented by molecular analysis based on rDNA-ITS sequencing to assess genetic variability. Results revealed significant intraspecific variation among P. neglectus populations, indicating the presence of distinct genetic lineages associated with different cereal hosts and soil environments. Phylogenetic analysis showed clustering of isolates with partial geographic and host-related structuring, suggesting adaptive divergence within the species. Variation in reproductive potential and pathogenicity was observed among populations, with certain lineages exhibiting higher virulence and greater capacity for root invasion and lesion formation. Environmental factors, particularly soil texture and moisture levels, influenced population distribution and infection intensity. The study highlights that intraspecific diversity contributes to variability in disease expression and complicates nematode management strategies in cereal agroecosystems. These findings emphasize the importance of integrating molecular diagnostics with pathogenicity assessments to improve understanding of P. neglectus population structure and to support the development of effective, targeted nematode management approaches.