ResumoO uso de extratos vegetais com propriedades nematicidas no controle de fitonematóides representa mais uma alternativa para os pequenos produtores, com valor prático e econômico, e sem riscos de contaminação do ambiente. A adição ao solo dos extratos aquosos de 20 espécies de plantas foi avaliada sobre a população de Meloidogyne javanica em plantas de tomateiro, em casa de vegetação. Estas foram divididas em dois grupos e avaliadas em dois experimentos separados. No mesmo dia em que se infestou o solo com 5.000 ovos do nematóide, adicionou-se 20 mL dos extratos aquosos obtidos de folhas de artemísia (Chrysanthemum parthenium), bardana (Arctium lappa), capim cidreira (Cymbopogon citratus), carqueja (Bacharis trimera), cavalinha (Equisetum sp.), cinamomo (Melia azedarach), hortelã (Mentha sp.), mamona (Ricinus communis), manjericão (Ocimum basilicum), melão-de-São-Caetano (Momordica charantia), arruda (Ruta graveolens), falso-boldo (Coleus barbatus), confrei (Symphitum officinalis), erva-de-bicho (Polygonum acre), feijão-de-porco (Canavalia ensiformis), funcho (Foeniculum vulgare), guiné (Petiveria alliacea), mentrasto (Ageratum conyzoides), mucunacinza (Mucuna pruriens) e nim (Azadirachta indica). Água destilada foi adicionada ao solo como tratamento testemunha. Após 60 dias, avaliou-se a altura das plantas, o peso fresco da parte aérea e da raiz e os números de galhas e de ovos por sistema radicular. Os extratos de hortelã, bardana e mamona reduziram o número de galhas em 75,6%, 65,7% e 54,4%, e o número de ovos em 81,7%, 75,9% e 56,6%, respectivamente. Palavras-chave: Fitonematóides, controle alternativo, nematóides das galhas, compostos naturais AbstractThe use of plant extracts with nematicidal properties to control plant nematodes can be a useful alternative to small farmers, regarding its low cost and non-toxic effects. The effect of the addition into the soil of aqueous extracts of 20 plant species on Meloidogyne javanica in plants of tomato was studied at greenhouse conditions. These were divided into two groups and evaluated in two separate experiments. The soil in the 2.0 L pots was infested with 5,000 eggs and, in the same day, it was applied 20 mL of aqueous extracts of the 20 plant species (Chrysanthemum parthenium, Arctium lappa, Cymbopogon

Root-knot nematodes (RKN), from the Meloidogyne genus, have a worldwide distribution and cause severe economic damage to many life-sustaining crops. Because of their lack of specificity and danger to the environment, most chemical nematicides have been banned from use. Thus, there is a great need for new and safe compounds to control RKN. Such research involves identifying beforehand the nematode proteins essential to the invasion. Since G protein-coupled receptors GPCRs are the target of a large number of drugs, we have focused our research on the identification of putative nematode GPCRs such as those capable of controlling the movement of the parasite towards (or within) its host. A datamining procedure applied to the genome of Meloidogyne incognita allowed us to identify a GPCR, belonging to the neuropeptide GPCR family that can serve as a target to carry out a virtual screening campaign. We reconstructed a 3D model of this receptor by homology modeling and validated it through extensive molecular dynamics simulations. This model was used for large scale molecular dockings which produced a filtered limited set of putative antagonists for this GPCR. Preliminary experiments using these selected molecules allowed the identification of an active compound, namely C260-2124, from the ChemDiv provider, which can serve as a starting point for further investigations.

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The objective of this work was to study the imbibition profile in water or in polyethylene glycol 6000 osmotic solution and the effect of the osmoconditioning on the germination and vigor of seeds of six soybean cultivars-Confiança, UFV-16, Splendor, Garantia, UFVS 2005 and UFV-18. The cultivars were grown in the field at Viçosa, Minas Gerais, in a randomized complete block design, the seeds were harvested at the R8 stage and 15 and 30 days later. Seed samples of each cultivar per harvest time and replication were soaked in distilled water (control) or osmoconditioned in-0.8 MPa PEG 6000 solution at 20 °C, for 96 h, in the presence of 0.2% Captan fungicide. Vigor and viability of the seeds were evaluated by the first and final counting in the germination test on paper rolls and speed of seedling emergence on sand seedbed. The imbibition speed and the humidity of the osmoconditioned seeds of all six cultivars and three harvest times were lower than of those seeds soaked in water. The germination and vigor of osmoconditioned seeds were higher for all cultivars at all harvest times, mainly with 30 days harvest delay, indicating the conditioning efficacy to increase the germination of weathered seeds.