RESUMO

Duddingtonia flagrans is a biological alternative to the use of anthelmintic drugs in ruminants. This fungus must be ingested by the animal, pass through the cavities of the digestive tract and reach the feces where it develops traps that capture the nematodes. The severe conditions encountered in this process negatively affect the fungus, which is reflected in the low recovery rates compared to the amount administered. The aim of this study was to evaluate independently the in vitro effect of typical physical and chemical conditions of the gastrointestinal cavities of ruminants on the concentration, viability, and the in vitro nematode predatory ability of the chlamydospores of D. flagrans. The factors evaluated individually were pH (2, 6, and 8), temperature (28 ± 2°C and 39 ± 2°C), exposure to artificial saliva, and milling. The results showed that the concentration and viability of D. flagrans were not affected by the action of pH, temperature, milling, or exposure to artificial saliva. Regarding the in vitro nematode predatory ability, a reduction was observed after the milling process and the exposure for 24 h at different pH.

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RESUMO

The in vitro effect of silver nanoparticles of the Duddingtonia flagrans filtrate enriched with chitin was evaluated on infective larvae of cyathostomins (L3). After biosynthesis, an assay was carried out with two experimental groups in microtubes, for a period of 24 h: G1 (AgNP's-D. flagrans (43.4 µg/mL) + 120 L3) and G2 (distilled water + 120 L3). At the end of this period, AgNP's-D. flagrans (G1) demonstrated an effect on L3 with a 43% reduction (p < 0.01) in relation to G2. Thus, the authors suggest new designs with AgNP's-D. flagrans for the control of cyathostomins.

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RESUMO

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(AU)

Assuntos

RESUMO

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

Assuntos

RESUMO

Biological control through the use of nematophagous fungi is a sustainable alternative for combatting helminthes in domestic animals and allows a reduction in the use of anthelmintics. The objective of this research was to evaluate the efficacy of the Arthrobotrys cladodes var macroides fungus in a pelleted formulation, based on sodium alginate and administered twice a week orally, as an alternative for the biological control of nematodes in field-grown young cattle. The experiment was conducted in a farm located in the municipality of Viçosa, MG, where 12 cattle, seven to nine months old, were allocated in two groups (treated group and control group) and distributed in pickets of Brachiaria decumbens, naturally infested with nematode larvae. The animals in the treated group received 1g of sodium alginate matrix pellets for every 10 kg of animal live weight, containing the nematophagous fungus Arthrobotrys cladodes var macroides and administered twice a week in conjunction with commercial feed. In the control group, each animal received 1 g of pellets for every 10 kg of animal live weight, without fungal mycelium added to the feed. Samples of feces and pastures were collected fortnightly for 12 months. The results showed that the most prevalent nematode genera in the coprocultures were Haemonchus sp., Cooperia sp. and Oesophagostomum sp., reflecting the results found in forage. The pasture that contained the animals that received feed with the fungus presented a reduction of 59% and 52% of larvae recovered at distances of 20 cm and 40 cm from the fecal pats, respectively. The mean number of eggs per gram of feces each month and animal body weight did not differ (p > 0.05) between the treated and control groups. Stool and soil samples from both groups were colonized by A. cladodes fungus and other fungi. Administration of Arthrobotrys cladodes var macroides mycelium by means of a sodium alginate matrix twice weekly reduced larval infestation of the surrounding pasture, indicating that this fungus may be a promising biological control of infecting forms of nematodes present in the environment.

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RESUMO

The objective of this study was to evaluate, in vitro, the colonization and destruction of ants of the genus Camponotus sp. by the ovicidal fungus Pochonia chlamydosporia (VC4 isolate), in the southeast region of Brazil. The insects used in the experiment were worker ants of the genus Camponotus sp., collected periodically in the environment and immediately transported to the laboratory in test tubes. Then, VC4 growth was promoted in 2% chitin agar medium (2% WQ) to obtain a fungal solution containing conidia and/or chlamydospores. Two experimental groups were formed. Treated group consisted of Petri dishes containing 2% agar-water culture medium (2% WA) with nine live insects and 20 µL of fungal solution at the concentration of 15,000 conidia/chlamydospores. Control group consisted of Petri dishes containing 2% WA culture medium and nine live insects. The dishes in the treated and control groups were incubated in BOD at 25 ± 1 °C and 80 ± 10% relative humidity for 4 days. After 4 days, it was observed that the VC4 had grown, colonized, and caused the destruction of the ants. The fungus P. chlamydosporia was efficient at colonizing and destroying the urban ants collected on an experimental basis. Thus, it could open up new ways to reduce the use of chemical compounds in the future, decreasing health and environmental problems.

RESUMO

The strain Purpureocillium sp. UdeA0106 is an antagonist of nematodes, fungi, and garden symphylans from crops with high economic importance in Colombia (Salazar 2013; Salazar et al. 2014; Cardona et al. 2014; Gallego et al. 2014) and is being studied to be proposed as new species. It was included on the 1000 fungal genomes project to elucidate its phylogenetic relationships with other fungi. Purpureocillium's mitogenome has 23,495 bp of circular size. It contains 15 protein-coding genes without duplications (PCGs), corresponding to the 60% of its total length, 23 transfer genes (7.6% tRNA), two of them duplicated (trnR and trnM), and two ribosomal genes (17.6% rRNA) and a GC content of 28.44%. A phylogenetic tree was proposed using their 14 PCGs mitochondrial genes and was compared with other fungi of the Subphylum Pezizomycotina. Phylogenetics relationships showed UdeA0106 to be close to P. chlamydosporia and M. anisopliae forming a cluster with other fungal biocontrol agents and separated the strain of plant pathogenic fungi.

RESUMO

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.

RESUMO

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.(AU)

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.(AU)

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RESUMO

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.

Assuntos

RESUMO

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.

RESUMO

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.

RESUMO

In order to verify the viability after passage through the gastrointestinal tract, conidia of nematophagous fungus, Monacrosporium thaumasium, were orally administered to goats. Fecal samples were collected 18 to 30 hours after inoculation. It was verified fungus growth and predatory activity against Panagrellus spp in plates made with feces collected at 21 and 24 hours after inoculation. There was a 79.24% reduction of Haemonchus contortus infective larvae number from coprocultures prepared with feces collected at 24 hours after the fungus administration. The fungus M. thaumasium maintained predatory activity over H. contortus, after passage through the gastrointestinal tract of goat.

Conídios de Monacrosporium thaumasium foram administrados por via oral a caprinos para verificar a viabilidade desse fungo nematófago após passagem pelo trato gastrintestinal. Foram realizadas amostragens de fezes de 18 a 30 horas após inoculação. Constatou-se crescimento do fungo e atividade predatória contra Panagrellus spp em placas confeccionadas com fezes coletadas 21 e 24 horas após a inoculação. Houve uma redução média de 79,24% no número de larvas infectantes de Haemonchus contortus provenientes de coproculturas preparadas com fezes coletadas 24 horas após a administração do fungo. O fungo M. thaumasium manteve atividade predatória sobre H. contortus, após passagem através do trato gastrintestinal de caprinos.

RESUMO

In order to verify the viability after passage through the gastrointestinal tract, conidia of nematophagous fungus, Monacrosporium thaumasium, were orally administered to goats. Fecal samples were collected 18 to 30 hours after inoculation. It was verified fungus growth and predatory activity against Panagrellus spp in plates made with feces collected at 21 and 24 hours after inoculation. There was a 79.24% reduction of Haemonchus contortus infective larvae number from coprocultures prepared with feces collected at 24 hours after the fungus administration. The fungus M. thaumasium maintained predatory activity over H. contortus, after passage through the gastrointestinal tract of goat.

Conídios de Monacrosporium thaumasium foram administrados por via oral a caprinos para verificar a viabilidade desse fungo nematófago após passagem pelo trato gastrintestinal. Foram realizadas amostragens de fezes de 18 a 30 horas após inoculação. Constatou-se crescimento do fungo e atividade predatória contra Panagrellus spp em placas confeccionadas com fezes coletadas 21 e 24 horas após a inoculação. Houve uma redução média de 79,24% no número de larvas infectantes de Haemonchus contortus provenientes de coproculturas preparadas com fezes coletadas 24 horas após a administração do fungo. O fungo M. thaumasium manteve atividade predatória sobre H. contortus, após passagem através do trato gastrintestinal de caprinos.