Search

The fact that fungi as biological control agents have become in an important alternative, compared with the use of chemicals for the pest control, has brought new challenges to the scientific research. The introduction of a new biocontrol product in market is a long process and has to pass several steps including detection, efficacy tests, toxicological studies, mass production, formulation, authentication, etc. There is conscientious increment about a real need; these analyses should be made as routine. The antagonist identity and genetic stability have to be precisely established for the registration. Rely on some tools for the genetic monitoring and the BCA released environmental fate is also important. There are different conventional techniques to cover these issues, but sometimes they are not sufficient. The molecular techniques can assist to researchers to identify and study the biodiversity and select the proper candidates for the biological control. These techniques can be an alternative as quality control tests. But, the selection of the right one, based on the target microorganism specific characteristic and the required information needed for evaluating a particular step, is a fundamental premise. The aim of this article is to show a panoramic at the current situation about the use of different techniques in the biological control, with emphasis in the nematophagous fungus Pochonia chlamydosporia. [ABSTRACT FROM AUTHOR]

Trichoderma species fungi secret hydrolytic enzymes which allow them to penetrate the cell walls of phytopathogenic fungi. The glucanases are enzymes that hydrolyze the (3-glucans of the cell wall of phytopathogens such as Sclerotium rolfsii, Rhizoctonia solani and Pythium sp. The aim of this work was to carry out the dynamics of glucanase induction of ten Trichoderma spp. isolates evaluating the enzymatic activities at the first, third, fifth and seventh days of the cultures in three liquid media: basal medium, basal medium supplemented with chitin 0,5% and basal medium supplemented with gelatine 0,2%. The isolates 1, 13 y 17 reached the highest levels of glucanase specific activity during the induction with the basal medium supplemented with gelatine. The basal medium also resulted to be a good inductor of those enzymes. [ABSTRACT FROM AUTHOR]

The endophytic and stimulating effect of four strains of Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg (Ta. 13, Ta. 78, Ta. 85, and Ta. 90) on Phaseolus vulgaris (Cv. BAT-304) was evaluated under semi-controlled conditions. The number of leaves and roots, plant height, root length, fresh foliar and root mass, dry foliar and root mass, endophytic capacity in roots, foliar content of N, P, K and the induction of peroxidase enzymes (POD), polyphenoloxidases (PPO), and phenylalanine ammonium lyases (PAL) were determined. The evaluations were carried out in 15-day old plants sown at two times:1) plant sowing and soil inoculation with Trichoderma at the same time, 2) planting seven days after soil inoculation with the fungus). The strain Ta. 85 produced the greatest stimulation in terms of number of leaves, plant height and root length with the first time of sowing. All the strains were endophytic for the bean cultivar studied. Ta. 90 and Ta.85 increased the leaf content of N with the first sowing time, whereas Ta. 78, Ta. 85, and Ta. 90 did it with the second sowing time. Only Ta. 78 increased the leaf K with respect to the control with the second sowing time. The plants treated with Ta. 78 showed higher POD, PPO and PAL enzymatic activities with respect to the control plants. Ta. 13 increased POD and PPO activities, whereas Ta. 85 and Ta. 90 only the PPO activity. The results suggest that strain Ta. 85 inoculated at bean planting is efficient in stimulating growth, whereas Ta. 78 stood out in nutrition and induction of possible resistance in this crop. [ABSTRACT FROM AUTHOR]

Use of fungi of the Trichoderma genus for the biological control of pests and diseases is based, to a large extent, on their secretion of hydrolytic enzymes. The latter include chitinases and glucanases, which degrade the cell wall of phytopathogenic fungi as well as the cuticle of insects and nematodes. The aim of this study was to assess the induction dynamics of chitinases and glucanases in ten strains of Trichoderma spp. grown in liquid media with different inducers: basal medium, basal medium supplemented with 0.5% chitin and basal medium supplemented with 0.2% gelatin. Chitinase and glucanase activity were evaluated at the first, third, fifth and seventh day of culture. The highest values of chitinase activity were obtained in basal and basal media supplemented with chitin; β-1.3-glucanase, on the other hand, exhibited higher levels of activity in basal and basal media supplemented with gelatin. [ABSTRACT FROM AUTHOR]

Use of fungi of the Trichoderma genus for the biological control of pests and diseases is based, to a large extent, on their secretion of hydrolytic enzymes. The latter include chitinases and glucanases, which degrade the cell wall of phytopathogenic fungi as well as the cuticle of insects and nematodes. The aim of this study was to assess the induction dynamics of chitinases and glucanases in ten strains of Trichoderma spp. grown in liquid media with different inducers: basal medium, basal medium supplemented with 0.5% chitin and basal medium supplemented with 0.2% gelatin. Chitinase and glucanase activity were evaluated at the first, third, fifth and seventh day of culture. The highest values of chitinase activity were obtained in basal and basal media supplemented with chitin; β-1.3-glucanase, on the other hand, exhibited higher levels of activity in basal and basal media supplemented with gelatin. [ABSTRACT FROM AUTHOR]