Plants can stablish symbiosis with arburcular mycorrhiza fungi (AMF), in which the fungus uses carbohydrates synthesized by plant photosynthesis in exchange for soil nutrients. AMF symbiosis may benefit plants by increasing the rates of nutrient uptake, tolerance to abiotic stresses, protection against pathogens and, by promoting resilience of forest species to adverse conditions. Knowledge about the diversity of mycorrhizas may help stablish relationships of species selection, AMF production and inoculation. Therefore, the objective of this review is to compile information to identify existing patterns in AMF diversity in Brazilian forest ecosystems. Compilation was based in 74 articles (in English, Portuguese and Spanish languages) searched in the Web of Knowledge and selected for having the keywords “forest”, “diversity”, “mycorrhizal” and “Brazil”, and that identified AMF species by spore morphology. Compilation resulted in a list of 164 AMF species and indicated that AMF species are not plant host specific but they are selected by environmental conditions where the host grows. Some AMF species were ubiquitous and some were rare in forest ecosystems. Rare AMF species may be an artefact of AMF identification because, in comparison to molecular tools, spore morphology may underestimate AMF diversity. Four AMF species, Acaulospora scrobiculata, Acaulospora foveata, Clareoideglomus etunicatum and Glomus macrocarpum, were ubiquitous to several biomes, existed in different stage of forest succession and seemed to be adapted to different forest managements. Therefore, A. scrobiculata, A. foveata, A. mellea, C. etunicatum and G. macrocarpum could have potential to be used as AMF inoculant in forest species.

O Eucalyptus benthamii é uma das principais espécies de eucalipto plantadas na região Sul do Brasil, por sua resistência a geadas e por seu uso na produção florestal de madeira para fins energéticos. Na produção de mudas, uma das principais doenças ocorrentes em viveiros é o mofo-cinzento, causado pelo fungo Botrytis cinerea. Uma das alternativas para o controle dessa doença é o controle biológico com fungos endofíticos, os quais podem competir com os patógenos foliares de mudas de eucalipto. O objetivo deste trabalho foi isolar os fungos endofíticos provenientes de mudas de E. benthamii, identificá-los e selecioná-los para o controle de B. cinerea. Eles foram isolados do interior de tecidos vegetais desinfectados, identificados de acordo com critérios macro e micromorfológicos e classificados a partir de testes de controle biológico in vitro. Os resultados evidenciaram o potencial antagonista dos fungos Aspergillus sp., Penicillium sp. e Trichoderma sp. Nenhum desses fungos causou lesões em mudas de E. benthamii. Palavras-chave: Mofo-cinzento; eucalipto; viveiro. Abstract In vitro selection of endophytes for biological control of Botrytis cinerea in Eucalyptus benthamii. Eucalyptus benthamii is one of the main eucalypt species planted in Southern Brazil, due to its resistance to frost and its use in the production of forest wood for energy purposes. During the production of seedlings, the main disease occurring in forest nurseries is gray-mold caused by the fungus Botrytis cinerea. One alternative for control this disease is biological control with fungal endophytes, which can compete with the foliar pathogens of eucalypt seedlings. The objective of this study was to isolate endophytic fungi from seedlings of Eucalyptus benthamii, identify and select them for B. cinerea control. These were isolated from the interior of disinfected plant tissues, identified according to macro and micromorphological criteria, and based on tests of biological control in vitro. The results revealed the potential antagonist of Aspergillus sp., Penicillium sp. and Trichoderma sp. No fungi caused lesions in E. benthamii seedlings. Keywords: Gray-mold; eucalypt; nursery.

Black wattle (Acacia mearnsii De Wild.) is a tree legume native to southeast Australia, but present in all continents. Today it covers about 142,400 ha in Brazil, with plantations concentrated in the southern region of the country. Black wattle may form nodules and establish rhizobial symbiosis capable of fixing N₂, but rhizobial inoculation is not done in commercial plantations. About 40 kg ha⁻¹ of urea is applied during seedling transplantation. In this review, evidences by which rhizobial inoculation affects monoculture, mixed cultivation, and agroforestry black wattle production systems were searched in literature. Previous measurements in cultivated forests have indicated that biological nitrogen fixation in black wattle may provide up to 200 kg of N ha⁻¹ year⁻¹ to the soil. Therefore, rhizobia inoculation may bring several opportunities to improve black wattle production systems. Black wattle is not a very selective partner in the rhizobial symbiosis, but the genus Bradyrhizobium dominates the rhizobial diversity of black wattle nodules. Investigation on rhizobial diversity in soils where the crop is cultivated may represent an opportunity to find more effective rhizobia strains for inoculants. The successful history of biological nitrogen fixation in grain legumes must inspire the history of tree legumes. Microbiology applied to forestry must overcome challenges on the lack of trained professionals and the development of new application technologies.

Yerba mate (Ilex paraguariensis St. Hil.) is a native South American tree species cultivated in Argentina, Uruguay, Brazil, and Paraguay, and used to prepare a caffeine-rich infused drink called “mate” or “chimarrão”. Since 2016, up to 5% mortality of plants has been reported in commercial plantations at São Mateus do Sul and Arvorezinha in the state of Paraná (PR) and Rio Grande do Sul (RS), respectively. The death of the plants was noticed in plants of different ages after wilting of the leaves. Stem cross sections of symptomatic plants showed radial darkening. Fungal isolates were collected from internal darkened stem-base sections and grown in potato-dextrose-agar medium (PDA). The isolates were characterized using DNA sequencing and morphological analysis. Ten fungal colonies of a Ceratocystis sp. were obtained and deposited in the fungal collection of Embrapa Florestas, Colombo (PR), Brazil. These isolates produced ascomatal bases that were submerged in the agar. Bases were lobose, dark, 110-218 µm ...

Http://dx.doi.org/10.5902/1980509818448Eucalyptus benthamii é uma das espécies florestais plantada na região Sul do Brasil devido à sua resistência à geada. A principal doença em plantios comerciais é a mancha foliar causada por Cylindrocladium candelabrum. O objetivo deste trabalho foi avaliar a incidência e a severidade da doença em plantios de Eucalyptus benthamii, localizados em Rio Negrinho - SC. O levantamento foi realizado em três plantios (quatro, oito e 18 meses de idade), quantificando-se a incidência pelo percentual de plantas doentes e a severidade com uma escala diagramática que variou de 0 (sem mancha e desfolha) a 5 (mais de 75 % de desfolha). Quatro avaliações foram feitas no período de julho/2011 a junho/2013. A incidência média de árvores com a mancha foliar variou de 2,6 até 43,8 % das árvores, dependendo da idade, enquanto que a severidade média variou de 1,2 a 2,9, com menor severidade nas árvores de quatro e oito meses de idade. Verificaram-se relações diretas entre a intensidade da doença e o volume de precipitação pluviométrica, bem como entre severidade e altura da árvore. A relação entre incidência de plantas com mancha foliar variou de acordo com a altura das árvores.