Beneficial Role of Nematodes in Soil and Plant Health

Nematodes constitute a highly diversified group of organisms which are divided into parasitic and free-living forms. In addition to cause damage, they play a significant role in regulating primary production, predation, energy transfer, decomposition of organic matter, and nutrient cycling in soil ecosystems. The entomopathogenic nematodes (EPNs) in the families Heterorhabditidae and Steinernematidae, and their bacteria complex have attained the status of bio-pesticides. Nematodes are also used as models for studying complex biological systems in diverse scientific fields such as genetics, development, nutrition, environmental toxicology, pharmacology, and gerontology. The free-living nematodes (bacterivorous, fungivorous and omnivorous) are much less studied than the parasitic species although they play a significant role in decomposition of organic matter and nutrient cycling. This review has made an attempt to scan the various role the nematodes play apart from causing enormous damage to agricultural crops.