Assessment of reproductive traits of different root-knot nematode populations from Saudi Arabia

Summary Root-knot nematodes, Meloidogyne spp., are major constraints to crop production in Saudi Arabia; however, information on their pathogenic diversity and reproductive potential remains limited. Hence, this study aimed to collect populations of root-knot nematodes from crop-growing regions and assess their reproduction potential. Morphological and molecular characterisation classified the isolates into three species: Meloidogyne incognita , M. javanica and M. enterolobii . Glasshouse experiments were conducted twice under controlled conditions. Tomato plants were inoculated with 3000 eggs and juveniles per pot, and evaluated 8 weeks after inoculation to determine egg-laying female index (ELF), root mass and final population ( ). Significant variations were observed among root-knot nematode isolates in their ability to infect and reproduce on tomato plants. Meloidogyne enterolobii isolates exhibited the highest values of RF and ELF index, followed by M. incognita and M. javnanica . Trial effects were minimal, but the isolate × trial interaction was significant for root biomass, indicating a possible differential period modulation of pathogenicity. Altogether, M. enterolobii demonstrated superior reproductive potential, confirming its high pathogenicity and adaptability to Saudi conditions. These findings highlight the predominance of M. enterolobii and emphasise the need for region-specific management and host resistance strategies in tomato-based cropping systems.