Caenorhabditis elegans

Systematic position. Caenorhabditis elegans belongs to the phylum Nematoda, class Chromadorea, order Rhabditida, and family Rhabditidae. While primarily recognized as a fundamental model organism in developmental biology, its frequent occurrence in soil associated with decaying plant tissues makes it a relevant subject for agricultural soil science.

Crops and impact. This nematode is generally considered a bacteriophagous species rather than a direct parasite of living plant tissues. However, it frequently inhabits the rhizosphere of vegetable crops. Its presence often correlates with the presence of organic debris, where it contributes to the accelerated decomposition of root systems damaged by other pathogens.

Biology and life cycle. The life cycle of C. elegans is rapid, completing in about three days under optimal laboratory conditions. It progresses through four larval stages (L1–L4) to adulthood. A critical feature of its survival strategy is the formation of the dauer larva, a stress-resistant stage that allows the population to persist in soil even during unfavorable environmental conditions.

Damage patterns and pathogenicity. The economic damage caused by C. elegans is indirect but significant in greenhouse environments. By feeding on bacterial colonies and organic matter around the roots, these nematodes act as vectors for phytopathogenic bacteria, facilitating the progression of root rot and reducing the viability of young seedlings and transplants.

Protection measures. Effective management of C. elegans and associated rhizosphere risks involves a combination of cultural and preventive practices:

• Maintaining optimal soil drainage to prevent anaerobic conditions.
• Removing crop residues and decaying organic matter promptly.
• Implementing strict sanitation protocols in greenhouse production.
• Promoting a balanced soil microbial ecosystem to suppress opportunistic organisms.