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Background: The present study combines morphological and anatomical studies, cell wall chemical composition analysis, as well as assessment of the nutritional value of Guadua chacoensis foliage leaves.; Results: Foliage leaves of G. chacoensis are a promising source of forage because: (a) as a native woody bamboo, it is adapted to and helps maintain environmental conditions in America; (b) leaf anatomical studies exhibit discontinuous sclerenchyma, scarcely developed, while pilose indumentum, silica cells, prickles and hooks are also scarce; (c) it has a high protein content, similar to that of Medicago sativa, while other nutritional parameters are similar to those of common forages; and (d) glucuronoarabinoxylan, the major extracted polysaccharide, has one-third of the 4-linked β-d-xylopyranosyl units of the backbone substituted mainly with α-l-arabinofuranose as single stubs or non-reducing end of short chains, but also 5-linked α-l-arabinofuranose units, terminal β-d-xylopyranose and d-galactopyranose units, as well as α-d-glucuronic acid residues and small amounts of its 4-O-methylated derivative.; Conclusion: These results constitute the first report on this species, and as culms are utilized in constructions and crafts, the remaining leaves, when used as forage, constitute a byproduct that allows an additional income opportunity. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

Fusoid cells have been interpreted as cells or intercellular spaces, according to different authors. Here, structural and ultrastructural evidence is provided relative to the origin and changes experimented by chlorenchyma cells (“arm cells”) to differentiate into fusoid cells with large intercellular spaces between them. Performed studies and observations were made using Light and Transmission Electron Microscopy. Fusoid cells in Guadua species die but do not remain intact; instead, they uniformly collapse, delimiting conspicuous intercellular spaces which are bigger and different in shape from these cells. In transverse sections of mature and expanded bamboo leaf blades, usually seen in anatomical descriptions, the socalled “fusoid cells” are actually conspicuous intercellular gas spaces delimited by successive collapsed (and rarely not collapsed) fusoid cells. Also, we hypothesize possible relations or links between fusoid cell shape, structural function and apoplastic transport in bamboo leaves. Fil: Vega, Andrea Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; Argentina Fil: Castro, María A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina Fil: Guerreiro, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Guadua chacoensis (Poaceae) is a woody bamboo native from the Atlantic forest biome. Morphogenetic and physiological studies are scarce in bamboos, and tissue culture-based biotechnologies tools can be used to investigate ultrastructure and physiological processes as well as to mass-propagate specific genotypes. This study evaluated the effect of light and dark conditions on chloroplast biogenesis as well as in the endogenous levels of zeatin (Z), abscisic acid (ABA), gibberellic acid (GA4), and jasmonic acid (JA) during in vitro culture of G. chacoensis. An increase was observed, followed by a decrease in starch content in response to light treatment, and in contrast, in darkness, an accumulation of starch which is associated to amyloplast formation at day 30 was observed. No etioplast formation was observed even in the dark and this was associated with the presence of fully developed chloroplast at the beginning of the experiment. Z levels quantified showed distinct behavior, as in light, no difference in the levels was observed, except at day 10, and in darkness, the levels increased along the evaluation time. ABA, GA4, and JA biosynthesis increased along the time of evaluation in light condition. In contrast, in darkness, the levels remained unaltered, excepted for an increase in JA levels at day 10, suggesting a strong relationship between light and these phytohormone levels. Possible reasons why light’s presence and absence cause changes in chloroplast ultrastructure and hormone endogenous levels in in vitro cultivated culms of G. chacoensis are discussed. Keywords Bamboos · Micropropagation · Transmission electron microscopy · Plant physiology · Phytohormone Made available in DSpace on 2019-03-02T00:37:13Z (GMT). No. of bitstreams: 1 Polesi2019ArticleChloroplastUltrastructureAndHo.pdf: 1356355 bytes, checksum: 25b47e78e8251e1ff16794227f651cc5 (MD5) Previous issue date: 2019-01-10

Fil: Alchouron, Jacinta. Universidad de Buenos Aires. Facultad de Agronomia. Catedra de Botanica General; Argentina