Compatibility of fungicides with Trichoderma asperelloides and Azospirillum brasilense

The use of fungicides to control agricultural diseases has been increasing in agriculture. Thus, the biological control using fungus is an effective tool in the integrated diseases management. This study aimed to evaluate the compatibility of fungicides Certeza, Apron and Vitavax on the microorganisms Trichoderma asperelloides and Azospirillum brasilense. The experiments were conducted in vitro in a completely randomized design with a factorial arrangement 2 x 3 with three replications. The first factor composed of two doses and the second referred to the fungicides. The microorganisms were developed in PDA medium. After the medium has solidified, in a flow layer 10 µL of the fungal solution was added to each plate with the aid of an automatic pipette (D1, recommended dose; D2, double of recommended dose). Then, each Petri plate was centrally inoculated with a disc of Trichoderma asperelloides, in addition to the uninoculated control. For Azospirillum brasilense, the colony surface was scraped with the aid of a sterilized Drigalsky loop. Then, the filter of discs paper was dipped in the fungicides solution and placed on the medium surface. After this process, the plates were incubated in a BOD (Biochemical Oxygen Demand) at 26±2ºC and photoperiod 12 h. The parameters evaluated were a mycelial growth and sporulation. The results showed that there was no significant interaction between the factors. The fungicides Certeza (Tiofanato metílico + Fluazinam), Apron (Fludioxonil + Metalaxil-M) and Vitavax (Carboxina + Tiram) are considered compatible with Trichoderma asperelloides and Azospirillum brasilense. The fungicides can be used in an integrated disease management practices, priority must be given to use the products that have been shown to be less harmful

STUDY OF POTENTIAL ENDOPHYTES IN CONTROL OF THE CAUSAL AGENT IN TOMATO FUSARIOSIS

RESUMO: O presente trabalho objetivou avaliar a capacidade antimicrobiana in vitro, de diferentes extratos de fungos endofíticos, como alternativa no biocontrole de Fusarium oxysporum f.sp. lycopersici. Foram obtidos oito isolados endofíticos de plantas do Cerrado Maranhense e de interesse econômico, a saber: aroeira (Myracrodruon urundeuva Allemão), jenipapo (Genipa americana L.), milho (Zea Mays L.), mandioca (Manihot esculenta Crantz), vinagreira (Hibiscus sabidariffa L.) e graviola (Annona muricata L.). Os isolados endofiticos das espécies foram identificados em Aspergillus niger e Penicillium italicum, com características morfológicas distintas entre as colônias e todos os isolados endofíticos verificou-se crescimento mediano. Para a atividade antimicrobiana, foi realizada a extração dos metabólitos dos isolados endofiticos com os solventes: Acetato de Etila, Clorofórmio e Diclorometano, posteriormente realizado o bioensaio através do confronto direto do antagonista (endófito) sobre o Fusarium Oxysporum f.sp. lycopersici, raça 1, pelo método de difusão em ágar. Os extratos dos isolados endofíticos obtidos do solvente Clorofórmio apresentaram capacidade inibitória, assim interferindo no crescimento do Fusarium oxysporum f. sp. lycopersici raça. Que foram provenientes do caule milho (II) e de jenipapo, com diâmetros de 13mm e 11mm, respectivamente, os outros extratos dos isolados apresentaram halos de inibição inferior. PALAVRAS-CHAVE: antibiose, controle biológico, fitopatógeno.ABSTRACT: This study aimed to evaluate the ability antimicrobial in vitro of different extracts of endophytic fungi as an alternative in biocontrol of Fusarium oxysporum f.sp. lycopersici. Eight endophytic isolates were obtained from plants of the Cerrado Maranhense and economic interest, namely: mastic (Myracrodruon urundeuva Allemão), jenipapo (Genipa americana L.), maize (Zea Mays L.), cassava (Manihot esculenta Crantz), vinegar (Hibiscus sabidariffa L.) and soursop (Annona muricata L.). The isolated endophytic species were identified in Aspergillus niger and Penicillium italicum, with distinct morphological characteristics between the colonies and all endophytic growth medium was found. Antimicrobial activity was performed to extract the metabolites of endophytic isolates with solvents: Ethyl Acetate, Chloroform and Dichloromethane subsequently performed bioassay through direct confrontation of the antagonist (endophyte) on Fusarium oxysporum f.sp. lycopersici race 1, by agar diffusion method. The extracts of endophytic isolates obtained from solvent Chloroform showed inhibitory capacity, thus interfering with the growth of Fusarium oxysporum f. sp. lycopersici race 1 were derived stem corn (II) and jenipapo with diameters of 13 mm and 11 mm, respectively, the other extracts of the isolates showed inhibition halos below.   KEYWORD: antibiosis, biological control, plant pathogen

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved