Effect of the entomopathogenic nematode-bacterial symbiont complex on Meloidogyne hapla and Nacobbus aberrans in short-term greenhouse trials

CACCIA, M.G.; MARRO, N.; RONDAN DUEÑAS, J.C.; DOUCET, M. E.; LAX, P.

CROP PROTECTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2018

0261-2194

Meloidogyne hapla and Nacobbus aberrans are plant-parasitic nematodes that form galls in the roots of infectedplants and cause important economic losses. Entomopathogenic nematodes (EPNs) of the genera Steinernema andHeterorhabditis infect and kill insects via toxins produced by their symbiotic bacteria. EPNs have shown to havean antagonistic effect on different plant-parasitic nematode species in field and greenhouse trials. The aim of thepresent work was to evaluate, in tomato plants in greenhouse, the effect of the application of three ArgentineEPN isolates, their symbiotic bacteria and cell-free supernatants, on a population of M. hapla and two populationsof N. aberrans. Sixty days after inoculation, the number of galls and egg masses, the nematode reproduction factor(RF) and plant biomass were calculated. None of the plant-parasitic nematode populations or plant biomasswas affected by infective juvenile inoculation of the different EPN isolates. Bacterial action differed among populations;M. hapla was the most susceptible one, with a significant reduction in the number of galls, egg massesand RF caused by the application of the three bacterial strains. The most significant effect was produced by thecell-free supernatants on nematode RF, with reductions of 62?90%, caused by bacterial metabolites. The differentinoculation alternatives of the EPN-bacterial symbiont complex tested in the present work (infective juveniles,bacteria and cell-free supernatant) are compared for the first time for plant-parasitic nematode species