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No dia 18 de maio de 2023, Gustavo Ar\u00e9valo Rodrigues, aluno de Doutorado do Programa de P\u00f3s-Gradua\u00e7\u00e3o em Biodiversidade Vegetal e Meio Ambiente do Instituto de Pesquisas Ambientais (IPA), defendeu a tese de doutorado intitulada \u201cEvolu\u00e7\u00e3o e desenvolvimento dos \u00f3rg\u00e3os vegetativos a\u00e9reos em Euphorbia<\/em> sect. Brasilienses<\/em> V.W. Steinm. & Dorsey (Euphorbiaceae)\u201d.<\/p>\n A banca foi presidida pela orientadora, Dra. In\u00eas Cordeiro (IPA), e contou com a participa\u00e7\u00e3o da Dra. Adriana Hissae Hayashi (IPA), Dra. Cintia Kameyama (IPA), Dr. Odair Jos\u00e9 Garcia de Almeida (Unesp) e o Dr. Rivete Silva de Lima (UFBP).<\/p>\n Euphorbia<\/em> is considered as one of the biggest genera in number of species in angiosperms. The morphological diversity of the group is outstanding, occurring as herbs, geophytes, and trees, however, they are mostly recognized by their xerophytes species. The sect. Brasilienses <\/em>(subg. Euphorbia<\/em>) is a monophyletic group in the genus, with species having succulent and ribbed stems, which varies in number and disposition among species. Moreover, their leaves usually are reduced and early deciduous. Our primary goal was to describe the vegetative development and properly characterize the secretory structures associated to these organs in sixteen species of the genus. We also provide some possible phylogenetic relationships of the anatomical features between the sect. Brasilienses<\/em> species and their close-related phylogenetically lineages. Here, we use conventional and innovative anatomical techniques to analyze the vascularization of the succulent stems, as well to describe the micromorphology, anatomy and histochemistry of colleters. The key results obtained are related to a new interpretation of the stem ribs development in Euphorbia<\/em>, mainly in species of the sect. Brasilienses<\/em>. The ribs in these species originated from the increment of the basal leaf portion tissues, where a parenchymatic projection occurs in each leaf trace. Soon after the internode elongation, these traces are observed as collateral cortical bundles, and together with the parenchymatic projection compose an axial component. These component is observed in all species with succulent stems, having six distinct vasculature patterns. Colleters are identified with four morphotypes, being found in the axile and foliar lamina, and also composing stipules. Finally, the investigations related to the vascularization allowed us to propose a synapomorphy to the sect. Brasilienses<\/em>.<\/p>\n Keywords:<\/strong> colleters; cortical bundles; foliar adnation; stipules; parenchyma proliferation.<\/p>\n Euphorbia <\/em>\u00e9 considerada o maior g\u00eanero em n\u00famero de esp\u00e9cies dentre as angiospermas. Sua diversidade morfol\u00f3gica \u00e9 impressionante, ocorrendo como ervas, ge\u00f3fitas e \u00e1rvores, no entanto, sua maior diversidade \u00e9 em esp\u00e9cies xer\u00f3fitas. A se\u00e7\u00e3o Brasilienses <\/em>(subg. Euphorbia) <\/em>\u00e9 um grupo monofil\u00e9tico do g\u00eanero com esp\u00e9cies de caule suculentos e costados, os quais variam em n\u00famero e disposi\u00e7\u00e3o dentre as esp\u00e9cies. Al\u00e9m disso, suas folhas s\u00e3o sempre reduzidas e cedo caducas. O principal objetivo desta tese foi o de descrever o desenvolvimento vegetativo e propriamente caracterizar as estruturas secretoras associadas a estes \u00f3rg\u00e3os em dezesseis esp\u00e9cies do g\u00eanero, com o objetivo de descrever a anatomia e morfologia dos caules das esp\u00e9cies dessa se\u00e7\u00e3o. Aqui foram usadas t\u00e9cnicas usuais e inovadoras para estudos anat\u00f4micos, com o intuito de descrever o desenvolvimento e a vasculariza\u00e7\u00e3o caulinar, bem como a micromorfologia, anatomia e histoqu\u00edmica dos col\u00e9teres. Os principais resultados obtidos referem-se a uma nova proposta de interpreta\u00e7\u00e3o do desenvolvimento das costas caulinares em Euphorbia<\/em>, particularmente nas esp\u00e9cies de Euphorbia<\/em> sect. Brasilienses<\/em>. As costas nessas esp\u00e9cies se desenvolvem a partir do incremento dos tecidos basais foliares, onde uma proje\u00e7\u00e3o parenquim\u00e1tica ocorre em cada tra\u00e7o foliar. Logo ap\u00f3s o alongamento do entren\u00f3, estes tra\u00e7os foliares s\u00e3o observados como feixes corticais caulinares, constituindo, juntamente com a proje\u00e7\u00e3o parenquim\u00e1tica, um componente axial. Esse componente \u00e9 observado em todas as esp\u00e9cies com caules suculentos, apresentando seis diferentes padr\u00f5es de vasculariza\u00e7\u00e3o. Col\u00e9teres s\u00e3o identificados com quatro morfotipos diferentes, e s\u00e3o encontrados na axila e l\u00e2mina foliar, bem como constituindo est\u00edpulas. E por fim, o padr\u00e3o de vasculariza\u00e7\u00e3o dos caules e os tipos de col\u00e9teres das esp\u00e9cies de Euphorbia<\/em> sect. Brasilienses<\/em> permitiram propor uma poss\u00edvel sinapomorfia para a se\u00e7\u00e3o.<\/p>\n Palavras-chave:<\/strong> adna\u00e7\u00e3o foliar; col\u00e9teres; est\u00edpulas; feixes corticais; par\u00eanquima.<\/p>\n
\nEvolu\u00e7\u00e3o e desenvolvimento dos \u00f3rg\u00e3os vegetativos a\u00e9reos em Euphorbia<\/em> sect. Brasilienses<\/em> V.W. Steinm. & Dorsey (Euphorbiaceae)<\/h3>\n
\nABSTRACT<\/strong><\/h4>\n
RESUMO<\/strong><\/h4>\n
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<\/a>Gustavo Ar\u00e9valo Rodrigues<\/strong><\/a>
\nEvolu\u00e7\u00e3o e desenvolvimento dos \u00f3rg\u00e3os vegetativos a\u00e9reos em Euphorbia<\/em> sect. Brasilienses<\/em> V.W. Steinm. & Dorsey (Euphorbiaceae)<\/a><\/p>\n
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