Nematicidal and ovicidal activity of environmentally-friendly selenol ester derivatives against Meloidogyne incognita

Nematodes from the genus Meloidogyne are extremely harmful to agricultural crops due to their wide geographic distribution, variety of hosts, and strong reproductive capacity. The most used phytonematoid control method is the application of nematicides, which can also affect human health and the environment. Selenol ester derivatives have pharmaceutical applications, but little is known about their biological activities. We examined whether six selenol ester derivatives were nematicidal and ovicidal to the nematodes Caenorhabditis elegans and Meloidogyne incognita, and determined their toxicity to non-target organisms. The compound Se-p-methyl phenylselenobenzoate (2e) exhibited the lowest nematicidal and ovicidal Lethal concentration (LC50) to C. elegans (4.42 and 0.56 mg/L, respectively) and M. incognita (4.6 and 2.77 mg/L, respectively), which were similar or lower than the LC50 values for the control treatment with fluensulfone in C. elegans (4.07 and 6.05 mg/L, respectively) and M. incognita (43.07 and 49.63 mg/L, respectively). Compound 2e efficiently controlled the phytoparasite in greenhouse and reduced the number of galls and eggs present in tomato roots. Compared with the negative control, compound 2e was not toxic to other organisms such as Chlorella vulgaris algae, Galleria mellonella and Aedes aegypti larvae, and the aquatic protozoan Tetrahymena pyriformis. Our findings indicate that the selenol ester derivatives are potent and effective nematicides with no toxicity to the non-target organisms tested.