Species Identification and Pathogenicity of Globodera spp. on Potato in Cooler Highland Agricultural Zones

Abstract

Species identification and pathogenicity of Globodera spp. on potato were investigated in cooler highland agricultural zones to determine species distribution, genetic identity, and impact on crop performance. Field surveys were conducted in potato-growing highland regions, and soil and root samples were collected from fields exhibiting stunting, chlorosis, and reduced tuber yield. Cyst nematodes were extracted and identified using morphological characterization of cyst and second-stage juvenile traits, supported by molecular analysis based on PCR amplification and sequencing of rDNA regions. Results confirmed the presence of distinct Globodera species complexes associated with potato, with clear genetic differentiation among populations. Phylogenetic analysis indicated clustering of isolates corresponding to known potato cyst nematode species, suggesting localized adaptation and possible introduction pathways. Pathogenicity assays under controlled conditions demonstrated significant variation in virulence, with highly aggressive populations causing severe root damage, reduced nutrient uptake, and substantial yield losses. Cooler temperature conditions prevalent in highland zones were found to favor nematode survival and persistence in soil, contributing to long-term infestation risks. The study highlights the importance of accurate species-level identification for effective management of potato cyst nematodes. These findings support the implementation of integrated control strategies, including resistant cultivars, crop rotation, and quarantine measures to reduce the spread and impact of Globodera spp. in highland potato production systems.