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.; 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 formgalls in the roots of infected plants and cause important economic losses. Entomopathogenicnematodes (EPNs) of the genera Steinernema and Heterorhabditis infect and kill insects viatoxins produced by their symbiotic bacteria. EPNs have shown to have an antagonistic effecton 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 ofthree Argentine EPN isolates, their symbiotic bacteria and cell-free supernatants, on apopulation of M. hapla and two populations of N. aberrans. Sixty days after inoculation, thenumber of galls and egg masses, the nematode reproduction factor (RF) and plant biomasswere calculated. None of the plant-parasitic nematode populations or plant biomass wasaffected by infective juvenile inoculation of the different EPN isolates. Bacterial actiondiffered among populations; M. hapla was the most susceptible one, with a significantreduction in the number of galls, egg masses and RF caused by the application of the threebacterial strains. The most significant effect was produced by the cell-free supernatants onnematode 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 forplant-parasitic nematode species. Key words: plant-parasitic nematodes