Fungi of Rhizoctonia complex are mycorrhizal of orchids and may to germinate yours seeds and development the seedlings. In this context, our objective was to select a fungal isolate to promote seed germination and seedling development of Cyrtopodium saintlegerianum. Pelotons were found in the roots and three mycorrhizal fungi were isolated. We tested mycorrhizal isolates obtained from C. saintlegerianum roots and six mycorrhizal fungi from other orchids as well three pathogenic isolates (of rice and bean) to germinate the seeds in oatmeal-agar medium. Seeds not inoculated were used as control. The isolates En07 (Waitea circinata), Cs10 (Tulasnella sp.) and Ro88 (Rhizoctonia oryzae) were efficient to promote seed germination, but only En07 differing statistically of the control. The non-specific isolate En07 promoted germination in 81% of seeds and the specific isolate (Cs10) promoted 60%, evidencing the non-specificity mycorrhizal association in this orchid during germination. Axenic seedlings were inoculated with four mycorrhizal fungi (non-inoculated seedlings - control). After six months, the isolates En07 and Cs10 were efficient in the interaction with the seedlings, but did not differ to the control. Therefore, our results suggested that fungi of the Rhizoctonia complex can be used in the germination and seedling development of C. saintlegerianum.

ResumoAs orquídeas podem ser propagadas in vitro em meios de cultivo assépticos ou em simbiose com fungos micorrízicos. Epidendrum nocturnum ocorre em áreas de Cerrado e neste estudo objetivou-se a visualização de fungos micorrízicos em suas raízes bem como o cultivo assimbiótico de suas plântulas em diferentes meios e a micorrização in vitro. No desenvolvimento assimbiótico testou-se três meios de cultura em um ensaio e, em outro ensaio, foram testadas formulações alternativas do meio Knudson C modificado, com a adição de polpa de frutas. Fungos micorrízicos de orquídeas foram usados na micorrização in vitro. Pelotons foram visualizados nas raízes de E. nocturnum. O meio Knudson C modificado diferiu estatisticamente dos demais, nas duas intensidades luminosas, no primeiro ensaio. No segundo ensaio, após sete meses, os meios com formulação alternativa não diferiram estatisticamente entre si. Na micorrização in vitro as plântulas com o isolado fúngico En07 (Waitea circinata) apresentaram maior vigor visual em relação aos demais tratamentos, mas não houve diferença estatística com o controle. Os meios com formulação alternativa e o Knudson C modificado podem ser utilizados no desenvolvimento in vitro de E. nocturnum e o isolado En07 pode ser usado na micorrização visando estratégias de conservação desta orquídea. Palavras-chave: orquídea, desenvolvimento assimbiótico, micorrização, fungo. AbstractOrchids can be propagated in vitro in aseptic culture media or in symbiosis with mycorrhizal fungi. Epidendrum nocturnum occurs in areas of Cerrado and this study aimed to mycorrhizal fungi visualization in their roots and its asymbiotic growing their seedlings in different media and in vitro mycorrhization. In asymbiotic development was tested three culture in a test and, another test, alternative formulations of medium Knudson C modified with addition of fruit pulp. Mycorrhizal fungi orchids were used in in vitro mycorrhization. Pelotons were visualized in the roots of E. nocturnum. The medium Knudson C modified statistically different from the others, the two light intensities, in the first test. In the second test, after seven months, with the alternative formulation means were not statistically different from each other. In vitro mycorrhization plantlets with isolated fungal En07 (Waitea circinata) showed greater visual effect compared to other treatments, but there was no statistical difference with control. The media with alternative formulation and Knudson C modified can be used in vitro development of E. nocturnum, and the isolated fungal En07 can be used in order mycorrhization of this orchid conservation strategies.

An alternative method to control rice blast (Magnaporthe oryzae) is to include biological agent in the disease management strategy. The objective of this study was to assess the leaf blast-suppressing effects of rice phylloplane fungi. One Cladosporium sp. phylloplane fungus was shown to possess biocontrolling traits based on its morphological characteristics and an analysis of its 18S ribosomal DNA. Experiments aimed at determining the optimal time to apply the bioagent and the mechanisms involved in its rice blast-suppressing activities were performed under controlled greenhouse conditions. We used foliar spraying to apply the Cladosporium sp. 48 h prior to applying the pathogen, and we found that this increased the enzymatic activity. Furthermore, in vitro tests performed using isolate C24 showed that it possessed the ability to secrete endoxylanases and endoglucanases. When Cladosporium sp. was applied either prior to or simultaneous with the pathogen, we observed a significant increase in defence enzyme activity, and rice blast was suppressed by 84.0 and 78.6 %, respectively. However, some enzymes showed higher activity at 24 h while others did so at 48 h after the challenge inoculation. Cladosporium sp. is a biological agent that is capable of suppressing rice leaf blast by activating biochemical defence mechanisms in rice plants. It is highly adapted to natural field conditions and should be included in further studies aimed at developing strategies to support ecologically sustainable disease management and reduce environmental pollution by the judicious use of fungicidal sprays.

RESUMOOrquídeas são plantas muito procuradas em função da beleza e diversidade, de cores e formatos, de suas flores. Visando obter uniformidade, vigor e sanidade das mudas bem como produzir grandes quantidades para a comercialização usa-se a propagação in vitro. O objetivo deste trabalho foi avaliar a geminação e o desenvolvimento in vitro de Cyrtopodium saintlegerianum para aclimatação. Os meios MS, MS½, Knudson C modificado e Simplificado foram testados na germinação das sementes. No desenvolvimento das plântulas foram avaliados os meios Knudson C modificado, MS e MS modificado (adição de auxina e citocinina). Os meios MS, MS½ e Knudson C modificado promoveram germinação acima de 80% após sete dias. Contudo, no meio Simplificado as sementes germinaram após trinta dias. Nas duas avaliações, trinta e sessenta dias após o início do experimento, o meio Knudson C modificado foi eficiente para as variáveis observadas demonstrando seu potencial uso na germinação e desenvolvimento dessa espécie. Palavras-chave: Cyrtopodium saintlegerianum Rchb. f., Orchidaceae, meios de cultivo, reguladores de crescimento. ABSTRACT In vitro germination and development of the Cerrado epiphytic orchidOrchids are very popular plants due to the beauty and diversity, of colors and shapes, of their flowers. In order to obtain uniformity, vigor and sanity of the seedlings as well as to produce large quantities for the commercialization is used the in vitro propagation. The objective of this study was to evaluate the germination and in vitro development of Cyrtopodium saintlegerianum for acclimatization. The MS, MS½, Knudson C modified and Simplified media were tested on seed germination. In the development of the seedlings were evaluated Knudson C modified, MS and MS modified (addition of auxin and cytokinin). The MS, MS½ and Knudson C modified media promoted germination above 80% after seven days. However, in the Simplified medium the seeds germinate after thirty days. In the two evaluations, thirty and sixty days after the beginning of the experiment, the Knudson C modified medium was efficient for the observed variables demonstrating their potential use in germination and development of this species.

Rice production is affected by important pathogens such as Magnaporthe oryzae, Cochliobolus miyabeanus, Monographella albescens and Sarocladium oryzae, and orchid mycorrhizal fungi can contribute to the biocontrol of these diseases. The aim of this study was to characterize the antagonism mechanisms of W. circinata against rice pathogens. The indoleacetic acid (IAA) and lytic enzymes of W. circinata were quantified. The effectiveness of the bioagent and its metabolites was assessed in vitro. Antagonism in vivo against rice blast was also investigated. Waitea circinata produced IAA (2.3 µg ml-1), cellulase and polyphenol oxidase in a qualitative test. Glucanase, chitinase and protease were also produced in culture with cell walls and in co-culture with pathogens to explain antibiosis. W. circinata acts on direct antagonism by antibiosis and volatile metabolites. Mycelial suspension reduced M. oryzae conidial germination, appressorium formation, and rice blast by 61, 82 and 84%, respectively. W. circinata, a unique bioagent, controls four rice pathogens from mechanisms of parasitism and antibiosis. The results could contribute to new formulations containing this fungus, enzymes as well as its volatile metabolites.