Navegando por Autor "Veloso, Tomás Gomes Reis"

Agora exibindo 1 - 6 de 6

Characterization of seed germination and protocorm development of Cyrtopodium glutiniferum (Orchidaceae) promoted by mycorrhizal fungi Epulorhiza spp.
(Acta Botanica Brasilica, 2015-10) Pereira, Marlon Corrêa; Rocha, Diego Ismael; Veloso, Tomás Gomes Reis; Pereira, Olinto Liparini; Francino, Dayana Maria Teodoro; Meira, Renata Maria Strozi Alves; Kasuya, Maria Catarina Megumi
Cyrtopodium glutiniferum is an endemic orchid of Brazil with potential medicinal and ornamental applications. As mycorrhizal fungi are essential for the initiation of the orchid life cycle, the aim of this study was to determine the strains of mycorrhizal fungi suitable for seed germination and protocorm development of C. glutiniferum and to characterize the symbiotic development of protocorms. Seeds of C. glutiniferum were inoculated with nine mycorrhizal fungi, Epulorhiza spp., Ceratorhiza spp., Rhizoctonia sp., originally isolated from Brazilian neotropical orchids. Only Epulorhiza isolates promoted seed germination and protocorm development. Three Epulorhiza isolates (M1, M6 = E. epiphytica, M20 = Epulorhiza sp.) promoted protocorm development until leaf production at 63 days. The protocorms are comprised of parenchyma cells delimited by a unistratified epidermis; the parenchyma cells of the upper part of the protocorms are smaller than those located more towards the base. Intact and digested pelotons were observed inside of protocorms implying that the seedlings were capable of mycotrophy. Additionally, the development of a bud primordium only occurred after colonization by fungus. This study suggests that C. glutiniferum has a preference for strains of Epulorhiza and that fungus digestion is essential to protocorm development.
Cyrtopodium paludicolum germination with two Tulasnella isolates
(Acta Botanica Brasilica, 2018-01) Carvalho, Otieres Cirino de; Paiva Neto, Vespasiano Borges de; Padilha, Daly Roxana Castro; Veloso, Tomás Gomes Reis; Bocayuva, Melissa Faust; Soares, Deanna Carla Oliveira; Kasuya, Maria Catarina Megumi
Symbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. Th e aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its effi ciency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01) and Epidendrum secundum (M65), which has been successfully used a number of times in symbiotic germination. Th e experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. Th e mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identifi ed as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specifi city in the relationship between Cyrtopodium paludicolum and the fungi. Th e results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.
Efeitos ambientais no microbioma: trópicos e Antártica
(Universidade Federal de Viçosa, 2021-05-06) Veloso, Tomás Gomes Reis; Kasuya, Maria Catarina Megumi; http://lattes.cnpq.br/7872519897730290
The microorganisms play a key role in the in the main biogeochemical cycles, such as Carbon, nitrogen, sulfur, phosphorus, hydrogen and oxygen. In the rhizosphere and inside plant tissues, they can enhance plant growth, phytopathogen control, act as phytoregulators and increasing water and nutrient availability. These communities are directly affected by edaphoclimatic conditions. Thus, in the current scenario of climate change, the knowledge about the edaphic microbial diversity and the factors that shape it are essential to understand the potential of each soil, either for agricultural use or to understand the role of the soil face the climate change. There are many methods to study the microbial diversity, among them, the high-throughput DNA sequencing is the one of the most commonly used. This thesis is composed of three chapters where this technique was used to evaluate the diversity in each soil. The first title, entitled “Effects of environmental factors on microbiota of fruits and soil of Coffea arabica in Brazil” aimed to evaluate the effect of edaphic and topographic coditions in coffee crops on bacterial and fungal communities in soil and fruits. The second and third chapters addresses, respectively, the diversity of bacteria and fungi in soils recently exposed by deglaciation and ornithogenic soils. The microbial communities of fruits are affected mainly by tophographic factors (Altitude, facing slope and radiation), whereas microbial communities of soil, although also influenced by topographic factors, are strongly shaped by edaphic factors. Soils recently exposed by glacier retreat (young soils) displayed a greater variation in beta diversity than more developed soils. Lastly, the bacterial and fungal communities in the ornithogenic soils undergoes a substantial change after the abandonment by the penguins. Abandoned ornithogenic soils showed a greater predicted abundance of genes related to nitrification and sulfur metabolism. In short, both in tropical and antarctic soils, edaphoclimatic and temporal factors affect the structure of the microbial community. Keywords: Microbiota. Coffee. Ornithogenic soils. Glaciers. Next generation sequencing.
Fungal Community profile of Zygopetalum maxillare and Zygopetalum mackayi (ORCHIDACEAE)
(Universidade Federal de Viçosa, 2016-07-22) Veloso, Tomás Gomes Reis; Kasuya, Maria Catarina Megumi; http://lattes.cnpq.br/7872519897730290
The orchids seeds are minute and easily dispersed by the wind. However, due to this reduced size there is no enough reserve tissue to allow seed germination, so that the nutrients uptake in the in the first steps of life cycle is done by the association to a mycorrhizal fungus. Once distinct orchids species associate can associate with distinct fungi is important to know for each orchid which are the fungi associate, because the conservation of threatened orchids requires the conservation of the fungi. Here, culture-depedent and independent on approaches were used for studying the fungal profile community of two orchid species, Zygopetalum maxillare, an epiphyte, and Zygopetalum mackayi, a terrestrial. The results of culture-independent methods showed fungi of Ascomycota as the majority present. Both Zygopetalum species associate with Sebacinaceae and Ceratobasidiaceae, however, while species of Ceratobasidiaceae are shared by both orchids, Sebacinaceae are not. These results were corroborated by the results of culture-dependent approaches, although no fungi of Ceratobasidiaceae could be isolated. The isolates obtained by this study are potential to be used in seed germination and seedling development of Z. maxillare and Z. mackayi and for future use in reintroduction program.
Núcleo de Estudos em Microbiologia Agrícola (NEMA): integração e multiplicação de ações e conhecimentos
(Revista ELO - Diálogos em Extensão, 2017-10-20) Prates Júnior, Paulo; Cerqueira, Alan Emanuel Silva; Veloso, Tomás Gomes Reis; Correia, Hilberty Lucas Nunes; Kasuya, Maria Catarina Megumi
A troca de saberes tem grande importância para a ciência e estimula a dialética entre a razão e a emoção. Assim, surgiu o Núcleo de Estudos em Microbiologia Agrícola (NEMA) da Universidade Federal de Viçosa (UFV), com o objetivo de promover ações de ensino, pesquisa e extensão. O NEMA é subdividido em coordenações; essas despertam o voluntariado e a construção de um legado coletivo. O Dragon Dreaming tornou-se uma metodologia importante para a dinâmica do grupo, bem como os conceitos de Paulo Freire e Edgar Morin sobre conhecimento e respeito às diferenças. As atividades realizadas até o momento, como os Ciclos de Discussões em Bioinformática e Bioestatística, o Curso de Biossegurança, os Projetos "A importância da Microbiologia para a Agroecologia" e "Micro Cultural", são indicativos de avanços na integração do Departamento de Microbiologia e do nosso Programa de Pós-graduação e deste com a sociedade. Espera-se estimular o conhecimento crítico e ampliar as conexões entre ensino, pesquisa e extensão.
Symbiotic propagation of seedlings of Cyrtopodium glutiniferum Raddi (Orchidaceae)
(Acta Botanica Brasilica, 2013-07-19) Guimarães, Fernanda Aparecida Rodrigues; Pereira, Marlon Corrêa; Felício, Cristiane da Silva; Torres, Denise Pereira; Oliveira, Sabrina Feliciano; Veloso, Tomás Gomes Reis; Kasuya, Maria Catarina Megumi
In nature, orchid seeds obtain the nutrients necessary for germination by degrading intracellular fungal structures formed after colonization of the embryo by mycorrhizal fungi. Protocols for asymbiotic germination of orchid seeds typically use media with high concentrations of soluble carbohydrate and minerals. However, when reintroduced into the field, seedlings obtained via asymbiotic germination have lower survival rates than do seedlings obtained via symbiotic germination. Tree fern fiber, the ideal substrate for orchid seedling acclimatization, is increasingly scarce. Here, we evaluated seed germination and protocorm development of Cyrtopodium glutiniferum Raddi cultivated in asymbiotic media (Knudson C and Murashige & Skoog) and in oatmeal agar (OA) medium inoculated with the mycorrhizal fungus Epulorhiza sp., using non-inoculated OA medium as a control. We also evaluated the performance of tree fern fiber, pine bark, eucalyptus bark, corncob and sawdust as substrates for the acclimatization of symbiotically propagated plants. We determined germination percentages, protocorm development and growth indices at 35 and 70 days of cultivation. Relative growth rates and the effects of substrates on mycorrhizal formation were calculated after 165 days of cultivation. Germination efficiency and growth indices were best when inoculated OA medium was used. Corncob and pine bark showed the highest percentages of colonized system roots. The OA medium inoculated with Epulorhiza sp. shows potential for C. glutiniferum seedling production. Corncob and pine bark are promising substitutes for tree fern fiber as substrates for the acclimatization of orchid seedlings.