ABSTRACT
Two isolations of fungi from a bank of microorganisms in the Biological Sciences Laboratory at Escuela Superior Politécnica de Chimborazo were tested on the galling caused by Meloidogyne incognita in tomato seedlings grown in pots with substrate infested with a suspension of nematodes, with approximately 2000 juvenile stages (J2) from root galls of plants infested with M. incognita, taken from the Nematology laboratory of the Ecuadorian Agricultural Quality Assurance Agency (AGROCALIDAD). Pleurotus ostreatus was a fungus with nematicidal characteristics through production of toxins; while Trichoderma harzianum is a widely known fungus, although it is a plant growth promoter rather than a nematicide. The two fungi were formulated in wheat straw and rabbit manure. A complete randomized design (CRD) with three replications was used, with a chemical control (Fenamiphos) and an absolute control. Five grams of each formulation was applied per plant before the transplant. The number of galls in the roots, plant height, stem diameter, number of leaves and fresh and dry weight of the aerial part and roots of 180 tomato plants grown in greenhouse were evaluated at 60 days after transplant. The results showed that the two fungi reduced the number of galls and made it possible to obtain dry weights of the aerial and radicular part very close to the chemical control (10.09 and 3.39 g) with 8.68; 8.04; 2.96 and 3.25 g respectively. Besides Trichoderma harzianum proved to be a good promoter of root growth, therefore, the use of these bioformulates is a promising measure for the control of this phytonematode
Subject(s)
Solanum lycopersicum , Pleurotus , Trichoderma , TylenchoideaABSTRACT
Os clamidósporos são os principais propágulos utilizados como fonte de inóculo de Pochonia chlamydosporia em experimentos envolvendo o biocontrole do nematoide das galhas. O presente trabalho teve por objetivo avaliar o controle de Meloidogyne javanica em tomateiro por meio da aplicação ao solo de grãos de arroz colonizados pelo fungo contendo apenas micélio e conídio, sem a presença de clamidósporos. O isolado de P. chlamydosporia Pc-10 foi cultivado por 15 dias a 26°C em arroz previamente esterilizado em forno microondas. Dois experimentos foram conduzidos simultaneamente em casa de vegetação. No experimento 1, vasos de 2L de capacidade foram preenchidos com mistura solo:areia (1:1, v:v), contendo 3g kg-1 de solo de grãos de arroz colonizados pelo antagonista. No experimento 2, o fungo foi adicionado ao solo de vasos de 0,5L nas doses de 1, 5, 10, 15, 20, 25 ou 30g kg-1 de solo. Em seguida, o substrato de cada vaso foi infestado com 4.000 ovos de M. javanica e, após 15 dias, uma plântula de tomate foi transplantada. No experimento 1, a aplicação do fungo ao solo reduziu o número de galhas e de ovos do nematoide em 40% e 72,83%, respectivamente. No experimento 2, houve redução do número de ovos a partir de doses de 5g kg 1 de solo e no número de galhas, principalmente, nas doses de 25 e 30g kg-1 de solo. Conclui-se que P. chlamydosporia Pc-10 controlou M. javanica em tomateiro, mesmo quando aplicado ao solo na forma de grãos de arroz colonizados e sem a presença de clamidósporos.
Chlamydospores are the main propagules used as source of inoculum of Pochonia chlamydosporia in biocontrol experiments of root-knot nematodes. The objective of this study was to evaluate the control of Meloidogyne javanica on tomato plants by the soil application of rice grains colonized by Pochonia chlamydosporia containing just mycelium and conidia, without chlamydospores. The fungus (isolate Pc-10) was grown for 15 days at 26°C on grains of rice, previously sterilized in microwave oven. Two experiments were simultaneously carried out under greenhouse conditions. In the experiment 1, 2-L pots were filled with a soil:sand mixture (1:1, v:v) containing 3g kg-1 of soil of rice grains colonized by the antagonist. In the experiment 2, the fungus was added into the soil of 0.5L pots at the doses of 5, 10, 15, 20, 25 or 30g kg-1 of soil. The soil of each pot was infested with 4,000 eggs of M. javanica and one tomato seedling was transplanted in each pot after fifteen days. In the experiment 1, the application of the fungus into the soil reduced the number of galls and eggs of the nematode by 40% and 72.83%, respectively. In the experiment 2, it was observed the reduction of the number of eggs from the dose of 5 g kg-1 of soil and of the number of galls, particularly at the doses of 25 and 30g kg-1 of soil. As a conclusion, P. chlamydosporia controlled M. javanica on tomato plants even when applied into the soil as colonized-rice grains and without chlamydospores.
ABSTRACT
Paecilomyces lilacinus has potential for pests control. We aimed to analyze mycelial growth and spore production in P. lilacinus strains in several agro-industrial residues and commercial media. This study suggests alternative nutrient sources for fungi production and that the biotechnological potential of agro-industrial refuses could be employed in byproducts development.
Paecilomyces lilacinus apresenta potencial para controle de pragas. O objetivo deste trabalho foi analisar o crescimento micelial e a produção de esporos de linhagens de P. lilacinus em resíduos agro-industriais e meios comerciais. Este estudo sugere fontes alternativas para produção de fungos com potencial biotecnológico para desenvolvimento de bioprodutos.