Root-Knot Nematodes (Meloidogyne spp.): Biology, Plant-Nematode Interactions and Their Environmentally Benign Management Strategies

Root-knot nematodes pose a significant threat to agricultural production all over the world. They are ubiquitous, polyphagous, sedentary endoparasites and belong to genus, Meloidogyne. These biotrophic pathogens establish and maintain an intimate interaction with their host plants. Effectors are crucial for the entry of RKNs to the root of plants, subsequently leading to the formation of the specialized hypertrophied and multinucleate feeding sites for nematode growth and development. During the establishment and maintenance of nematode feeding sites, effectors are considered to play a critical role in the modulation of developmental and defence signaling pathways in host cells. Chemical nematicides are widely used in RKNs management strategies, despite their threat to environmental and human health. Recently, restrictions on using some chemicals have been enforced. So, there is a need of potential environmentally benign strategies to the management of RKNs. We will highlight most the effective strategies viz., biological control by bacteria and fungi and organic amendment by botanicals and oil cakes. Also taken into account are traditional strategies like cultural method, soil solarization and resistant cultivars. One of the best alternatives to chemical control of RKNs is biological control, which involves the use of predators and parasites to reduce the RKNs at various life stages (eggs, juveniles and adults), as well as the secretion of poisonous diffusible inhibitory metabolites which hamper the reproduction ability of RKNs. Here, we provide a brief review of the biology of the genus, Meloidogyne, plant-nematode interactions and various environmentally benign strategies.