In the frame of the TrichoNema (EU, Marie Curie) project, several Trichoderma species and isolates have been tested against plant-parasitic nematodes. The main targets are the root-knot nematodes Meloidogyne incognita and M. javanica, which are polyphagous sedentary-endoparasitic species, damaging worldwide. Biocontrol pot experiments are conducted mainly with T. hamatum-382 and a T. asperellum isolate, in nematode-inoculated sandy soil and potting-mixes, with vegetable and ornamental hosts, respectively. This report will focused on ornamental plants. Following screening of several hosts for their nematode sensitivity and growth enhancement by the fungi, Begonia and Impatiens have been chosen as the main model ornamental hosts. Trichoderma peat-wheat bran (fresh or dry) preparations were applied into the potting-mixes pre-planting, with or without pre-colonization of seedlings with the fungi. Trichoderma treatments reduced root galling and nematode reproduction, and plants growth was improved; treatments of seedlings usually enhanced the biocontrol activity. The Trichoderma preparations were applied also to soils naturally-infested with other polyphagous plant-parasitic nematodes: Pratylenchus penetrans (migratory endo-parasite), Rotylenchus robustus (ecto-parasite) and Paratylenchus projectus (ecto-parasite), planted with lettuce. Trichoderma treatments reduced the populations of the parasitic nematodes in soils from the pot experiments. Both Trichoderma species showed the ability to control several plant-parasitic nematodes. Fungal formulations are further tested with various application approaches, in order to define the most efficient methods for implementation of the biocontrol agents. Modes of action of these species are studied, aiming to improve their activity against plant-parasitic nematodes.

Comprehensive studies in our laboratory revealed the nematicidal potential of waste products from crustacean shells, or other proteinaceous compounds, for controlling species of several plant-parasitic nematodes. The bacteria Telluria chitinolytica sp. nov, and Bacillus cereus, which were isolated, grown and identified in our laboratory, appeared to have potential as bioagents to control the root-knot nematode Meloidogyne javanica. Intensive studies of the mode of action of these bacteria were carried out. The fungus Trichoderma exhibits biocontrol activity against the root-knot nematode M. javanica. Direct fungal parasitism is one of various possible mechanisms by which the fungus can act against the nematode. A constitutive GFP (green fluorescent protein)-transformant of T. asperellum was used to observe the fungal parasitism on nematode eggs and juveniles, using laser scanning confocal microscopy. The involvement of lytic enzymes in the process was demonstrated using inductive GFP-fungal transformants carrying a fusion of the proteinase or chitinase promoters with the gfp gene. These enzyme genes turned on during the interaction between the fungus and the nematodes. The direct fungal parasitism process on the nematode could be improved, in vitro, by using antibodies that bound to the surface of M. javanica J2 and eggs. The presence of these antibodies enhanced the attachment of the spores to the nematodes. This resulted in a significant enhancement of fungal parasitism on the nematodes.