Emanuele Junges

Compatibility of Beauveria bassiana commercial isolate with botanical insecticides utilized in organic crops in southern Brazil

Products based on botanical insecticides and entomopathogenic fungi have been widely used in organic farming, especially in southern Brazil. Thus, this study investigated, in vitro, the effect of aqueous extracts and commercial formulations of plants with insecticidal activity on Beauveria bassiana. The treatments comprised the botanical insecticides Neempro (azadiractin +3-tigloylazadirachtol), at the concentrations of 0.25, 0.5, 0.75, and 1.0% (v/v), and DalNeem (neem oil emulsifiable), at 0.5, 1.0, 1.5, and 2.0% (v/v) (both commercial formulations of Azadirachta indica (neem)), and the aqueous extracts, at the concentrations of 2.5, 5.0, 7.5, and 10.0% (w/v), of neem seeds, tobacco powder (Nicotiana tabacum), and catigua leaves (Trichilia clausenii). In potato, dextrose, and agar culture medium, the effects of each product on the mycelial growth and the production and viability of conidia of B. bassiana were estimated. According to the adopted compatibility index, the aqueous extracts of neem seeds and leaves catigua, depending on the concentration used, and the botanical insecticide Neempro, were classified as compatible with the entomopathogen, becoming important alternatives to integrate programmes of integrated pest management, especially in organic farming systems.

Variabilidade genética na região its do rDNA de isolados de trichoderma spp. (Biocontrolador) e Fusarium oxysporum f. sp. Chrysanthemi

A analise de caracteristicas morfologicas e culturais podem nao ser suficientes para uma caracterizacao precisa das especies de Trichoderma e Fusarium. Objetivou-se, neste trabalho, caracterizar a regiao do Espaco Interno Transcrito (ITS) do rDNA dos isolados UFSMT15.1, UFSMT16 e UFSMT17 de Trichoderma spp. utilizados no biocontrole de Fusarium oxysporum f. sp. chrysanthemi (isolado) UFSMF6. A extracao de DNA de cada isolado foi realizada a partir de micelio produzido em meio liquido Batata-Dextrose. As amostras de DNA genomico foram submetidas a Reacao em Cadeia da Polimerase (PCR) com os oligonucleotideos iniciadores universais ITS1 e ITS4 e o produto gerado foi sequenciado. Os fragmentos gerados pela amplificacao da PCR foram tratados com as enzimas de restricao HaeIII, HinfI e MboI. As regioes ITS1, ITS2 e 5.8S do rDNA desses isolados fungicos foram amplificadas com sucesso. A regiao ITS dos isolados UFSMT15.1, UFSMT16 e UFSMT17 de Trichoderma e o isolado UFSMF6 de Fusarium apresentaram uma banda simples com um fragmento de aproximadamente 600 pares de base (pb). As enzimas de restricao HaeIII, HinfI e MboI geraram polimorfismo de bandas entre os isolados. Com base nas analises da sequencia de DNA, os isolados UFSMT15.1, UFSMT16, UFSMT17 e UFSMF6 apresentaram maior similaridade com as especies Trichoderma koningiopsis, Hypocrea virens, Hypocrea lixii e Fusarium oxysporum, respectivamente.

Biopriming in bean seeds

ABSTRACT The incorporation of biological control organisms in seeds may help control pathogens and improve seedling performance. The aim of this study was to determine the effects of biopriming bean seeds with Trichoderma spp. and Bacillus subtilis using physiological conditioning, suspensions of biological structures and film coating techniques. Biopriming treatments with suspensions of biological structures were performed using the commercial products Agrotrich plus® and Rhizoliptus®. Water restriction was achieved using a PDA + Manitol (−0.7 MPa) medium for both Trichoderma spp. and Bacillus subtilis. Fifty disinfected bean seeds were placed in each petri dish. When the first radicle protrusion appeared in a seed, the other seeds were removed and dried in the laboratory environment for 48 h. Film coating was performed with the addition of the Color Seed® (150 mL kg−1) polymer to a treatment solution containing either the Trichoderma spp. or the Rhizoliptus product. Seeds were dried for 48 h in the laboratory. Seeds were covered and treated with one or both organisms. Biopriming with spore or bacterial cell suspensions promoted bean seedling growth, and the other techniques were not required to potentiate these benefits. Covering the primed bean seeds reduced seed quality. Both Trichoderma spp. and Bacillus subtilis promote bean seedling growth, benefitting the seedling even after it becomes independent of the seed reserves.

Effect of priming and seed-coating when associated with Bacillus subtilis in maize seeds

The aim of this study was to evaluate the effect on the physiological performance of maize seeds (Zea mays L.) of micro-priming with Bacillus subtilis associated with techniques of water restriction and seed-coating. The micro-priming of the seeds, without any additional techniques, was carried out using a commercial product, Rhizoliptus ® (Bacillus subtilis). Water restriction was carried out using a PDA medium (Potato - Dextrose - Agar) with mannitol (-0.7 MPa), upon which the culture was grown for 48hours. One hundred sterilized corn seeds were placed in each dish. Once root protrusion occurred in one seed, the rest were removed and kept in a laboratory environment for 48 hours. The coating was carried out by the addition of Seed Polymer Color HE (50 ml kg -1 ) to the priming mixture containing theBacillus subtilis. The seeds were kept for 48 hours in a laboratory environment. A treatment which associated seed coating and water restriction was used on the micro-primed seeds, together with a control treatment without the addition of Bacillus subtilis. The Bacillus subtilis has no effect on the health of the seeds it; does however contribute to the growth and development of the maize seedlings, being influenced by the micro- priming technique used. The use of water restriction associated with seed coating provides better results when micro-priming with Bacillus subtilis.

Trichoderma spp. na Produção de Mudas de Espécies Florestais

Seeds healthy and rapid development of seedlings of native species may be critical to the success of your establishment. This study evaluated the effect of Trichoderma spp. on seed and seedling development of Parapiptadenia rigida (angico), Cedrela fissilis (cedro) and Pelthophorum dubium (canafistula). The fungi was applied at different times of the production of seedlings. The fungi action was different between species and between the variables. Cedro was less responsive to application of Trichoderma spp. at any time of the seedlings production and the association of Trichoderma spp. With angico as the seed treatment favored the incidence of some pathogens, however the application later favored only the leaves development. In canafistula, the seed treatment provided control of pathogens associated and stimulated the emergence and production of leaves in seedlings, have potential to be used for seed treatment of this species.