[Show abstract][Hide abstract] ABSTRACT: Cassava, Manihot esculenta Crantz, is the most important crop for poor people in the tropics and subtropics. It is a woody plant scarcely studied from the anatomical viewpoint. Information on its anatomy is needed for use in plant breeding programs. An interspecific hybrid between cassava and M. oligantha Pax was obtained and artificially polyploidized by the second author. Hand cross sections were applied to the stem, colored by safranin and alcian blue, and mounted in synthetic resin. Tetraploid type showed a larger portion of medulla and absence of a growth ring. Vascular tissues in tetraploid were larger too. Both of these types had similar structure of vessel elements and articulated laticifers. Distribution of different tissues in the two types refers to more resistance to drought in the tetraploid type than in the diploid one.
No preview · Article · Nov 2012 · Plant Systematics and Evolution
[Show abstract][Hide abstract] ABSTRACT: An anatomical study of roots was conducted on two wild Manihot species, namely M. glaziovii and M. fortalezensis, and two cassava varieties, M. esculenta Crantz variety UnB 201 and M. esculenta variety UnB 122, to identify taxonomic differences in primary growth. Anatomical characters of cassava roots have been rarely investigated. Their study may help cassava breeders to identify varieties with economically important characters, such as tolerance to drought. We investigated tap and lateral adventitious roots of two specimens of each clone or species. Free-hand cross-sections of roots were drawn; these had been clarified with 20% sodium hypochlorite solution, stained with 1% safranin-alcian blue ethanolic solution, dehydrated in ethanol series and butyl acetate and mounted in synthetic resin. Anatomical differences among Manihot species and varieties were found in the epidermal and exodermal cell shape and wall thickness, content of cortical parenchyma, and number of xylem poles. Wall thickness of the epidermis and exodermis of tap root were similar in all species, while in the lateral root there were differences in cell shape and wall thickness. Epidermal cells with thick walls were found in the tap root of all species and in lateral roots of cassava varieties. This character is apparently associated with tolerance to drought and disease. The variation in the number of xylem poles of cassava varieties was larger (4-8) than in wild species (4-6), and appears to support the hybrid origin of cassava.
Preview · Article · Jan 2011 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: The objective of this research was to examine how much polyploidy may affect seed and root formation in cassava interspecific hybrids Manihot esculenta Crantz xM. oligantha Pax. A polyploid type was induced by colchicine treatment to lateral buds followed by propagating vegetatively arising stems. Cytogenetic and anatomical analyses were made on both polyploid and diploid types. The polyploid type showed extensive chromosome pairing and pollen viability. Multiembryonic ovule frequency increased in polyploid plants. Stalks became woody and propagation through roots difficult, the edible roots increased, however, in size.
[Show abstract][Hide abstract] ABSTRACT: The stem structure of two cassava cultivars, UnB 99 and UnB 110, known for being adapted to humid conditions and tolerant to drought, respectively, and of a wild species, Manihot glaziovii, was examined anatomically. Free-hand sections of secondary stems were made, clarified with 50% sodium hypochlorite solution, stained with 1% alcian-blue safranin, and then passed through an ethanol series and butyl acetate, followed by mounting in synthetic resin. M. glaziovii stems had dense prismatic and druse crystals in the cortical parenchyma, along with abundant gelatinous fibers. The pericycle fibers also had thicker walls. An absence of crystals, offset by abundant starch, was observed in clone UnB 99. In M. glaziovii, abundant tyloses were found in vessel elements; these were rare in clones UnB 99 and UnB 110. The wild species had larger vascular vessels; the secondary xylem showed very little starch, unlike UnB 99 and UnB 110. In clone UnB 110, starch was observed in the cortical region, and medulla and gelatinous fibers were found in the pericycle and secondary xylem. Brown stem color was found to be associated with tolerance to drought.
Preview · Article · Jan 2010 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: Cytogenetical analysis of the interspecific hybrid between M. esculenta (cassava) and M. oligantha revealed a fair chromosome pairing and a high viability of pollen grain. Studying ovule structure by clearing method showed multiembryony in 2.7% of ovules studied. Doubling chromosome number resulted in an increase of multiembryony up to 18% and reduction of pollen viability. Multivalent formation was observed too. In anatomical stem study of diploid and tetraploid hybrids it was noted larger number of vascular bundles in tetraploid type.
[Show abstract][Hide abstract] ABSTRACT: Four new Brazilian species from the genus Paspalum are described and illustrated:P. phaeotrichum, P. vexillarium, P. veredense, and P. clipeum Paspalum phaeotrichum is an annual with no obvious affinity to any known species of Paspalum, although it shares several characters with species of both P. subg. Ceresia and the ‘Bertoniana’ group. Paspalum vexillarium is presumably related to P. ceresia, with which it has been confused. Paspalum veredense shows affinities with both P. ellipticum and P. erianthoides. Paspalum clipeum is probably related to annual species of the ‘Plicatula’ group, although it lacks the dark brown upper florets typical of that group. Moreover, P. spissum, a species currently considered as a synonym under P. carinatum, is recognized on the basis of vegetative morphology, phenology and habitat. Keys to the treated species are provided when relevant, as well as a distribution map. Resumo—Quatro novas espécies de Paspalum do Brasil são descritas e ilustradas:P. phaeotrichum, P. vexillarium, P. veredense, e P. clipeum. Paspalum phaeotrichum é uma espécie anual sem afinidades obvias com outras espécies do gênero, embora compartilhe vários caracteres com P. subg. Ceresia e com o grupo ‘Bertoniana'. Paspalum vexillarium é supostamente relacionada a P. ceresia, com a qual tem sido confundida. Paspalum veredense tem afinidades com P. ellipticum e P. erianthoides. Paspalum clipeum é provavelmente relacionada às espécies anuais do grupo ‘Plicatula', embora não apresente os antécios superiores de cor marrom escura, típicos desse grupo. Além disso, P. spissum, uma espécie atualmente considerada como sinônimo de P. carinatum, é reabilitada com base na morfologia vegetativa, fenologia e habitat. São fornecidas chaves para as espécies tratadas, quando relevante, assim como um mapa de distribuição.
Full-text · Article · Jan 2009 · Systematic Botany
[Show abstract][Hide abstract] ABSTRACT: Este trabalho descreve Ouratea acicularis R. Chacon & K. Yamamoto (Ochnaceae), espécie nova da recentemente criada Estação Ecológica Serra Geral do Tocantins, Região do Jalapão, Tocantins, Brasil. Ouratea acicularis se assemelha mais a O. oleifolia (A. Saint-Hilaire) Engler. Ambas as espécies apresentam indumento pubescente nos ramos jovens, em ambas as faces foliares, nos eixos da inflorescência e na superfície externa dos botões florais, bem como folhas revolutas e botões florais agudos. Ouratea acicularis é a única espécie do gênero que possui lâminas foliares aciculares, ca. quatro vezes mais estreitas do que em O. oleifolia, com margens foliares fortemente revolutas que escondem a face abaxial da folha exceto a nervura mediana, bem como pela venação secundária inconspícua e botões florais mais estreitos. Anatomicamente, O. acicularis difere das outras espécies já estudadas por apresentar células da epiderme adaxial com lúmen em forma de ampulheta, tricomas pluricelulares fundidos na base, uma capa excepcionalmente desenvolvida de fibras e esclereídeos sobre os feixes vasculares colaterais, e clorênquima predominantemente bi-estratificado. Os ramos de O. acicularis são dignos de nota pela presença de cavidades secretoras conspícuas no córtex e pelo predomínio das fibras e dos elementos de vaso e xilema secundário.
Full-text · Article · Jan 2009 · Novon A Journal for Botanical Nomenclature
[Show abstract][Hide abstract] ABSTRACT: We examined the stem anatomy of Manihot esculenta Crantz and its hybrid with M. oligantha Pax. Cross-sections were stained with safranin-alcian blue. Manihot esculenta and its hybrid were found to have the same vascular structure in bicollateral bundles with internal phloem, which has been associated with drought resistance in other plant groups. If this association is established for cassava, it would facilitate the selection of lines that are more adapted to arid regions. This is the first report of internal phloem in this genus.
Full-text · Article · Jan 2009 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: Information on anatomical structure is needed by breeders working on improvement for drought tolerance. For studying the effect of polyploidy on cassava anatomy and its significance to tolerance to drought, we induced a polyploidy type of a selected clone (UnB 530) by applying an aqueous solution of 0.2% colchicine on lateral buds for a period of 12 h. The stem identified as tetraploid was propagated to produce the whole plant. Free-hand cross-sections of the median portion between stem internodes were made. They were clarified using 50% sodium hypochlorite solution, stained with 1% safranin-alcian blue, passed through an ethanol series and butyl acetate and mounted in synthetic resin. The tetraploid type showed more prismatic and druse crystals in the cortical parenchyma, and its pericycle fibers had thicker walls. The secondary xylem of tetraploid types was wider than diploid ones, having thinner walls and less starch.
Preview · Article · Feb 2008 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: There are different imported mounting mediuns commercialized at a relative high price for producing permanent slides of stained plant sections. These mounting mediuns become harder as they dry and preserve the good conditions of the plant material for indetermined time. The most used mouting mediuns to plant anatomy are: Canada balsam, Euparal®, Entellan® and Permount®. Aiming to reduce costs of producing permanent plant anatomy slides, alternative mediuns produced by brazilian industries, used mostly in artesanal work, were tested. Among the different synthetic mediuns tested, the verniz vitral incolor 500® showed properties compatible to be used as an efficient mounting medium, in substitution to the imported synthetic resins, at a lower cost and without alterations in the routine process. The verniz vitral incolor 500® allowed the production of permanent slides with plant organs sectioned hand free as well in rotatory microtome, after paraffin or historesin embedding, keeping unaltered the tissue and color charactheristics. The results showed that the tradicional resins can be replaced by the verniz vitral incolor 500®, not compromising the quality of the slides.
Full-text · Article · Jun 2006 · Acta Botanica Brasilica
[Show abstract][Hide abstract] ABSTRACT: The objective of this work was to study leaf anatomy of pineapple plants in order to improve acclimatization protocols. In vitro plantlets weighting an average of 3.1 g and greenhouse plantlets derived from in vitro stock material, after six and ten months of culture, weighting an average of 50.2 and 65 g, respectively, were used. Stomatal density was determined on the abaxial epidermis, at the basal, median, and apical portions of the leaf, using a completely randomized design under 2x3 factorial (two culture environments and three leaf regions) with six replicates. Thickness of the hypodermis, aquiferous and photosynthetic parenchyma were determined at the median portion of the leaf using a totally randomized design with three treatments and four replicates. The basic structure of the pineapple leaf under in vitro conditions did not change. However, stomatal frequency, cuticular and epidermal wall thickening, shape and sinuosity of the cell walls of aquiferous parenchyma and the presence of papillary cells were verified as a result of environmental conditions during culture, indicating phenotypic plasticity.
Full-text · Article · Feb 2006 · Pesquisa Agropecuária Brasileira
[Show abstract][Hide abstract] ABSTRACT: Resumo – O objetivo deste trabalho foi indicar caracteres anatômicos em folhas de plantas micropropagadas de abacaxizeiro, visando ao aperfeiçoamento do protocolo de aclimatação. Utilizaram-se plântulas micropropagadas in vitro e aclimatadas por seis e dez meses, apresentando, em média, 3,1, 50,2 e 65 g, respectivamente. A densidade estomática foi determinada na face abaxial da epiderme, nas regiões basal, mediana e apical da folha, usando o delineamento inteiramente casualizado em esquema fatorial de 2x3 (dois ambientes de cultivo e três regiões da folha), em seis repetições. A espessura da hipoderme, parênquimas aqüífero e clorofilado foi determinada na região mediana da folha, usando-se o delineamento inteiramente casualizado com três tratamentos em quatro repetições. A estrutura básica da folha do abacaxizeiro não se modificou, entretanto, ocorreram diferenças na freqüência estomática, no espessamento da cutícula e paredes da epiderme, formato e sinuosidade das paredes das células do tecido aqüífero e presença de células papilosas nos diferentes ambientes de cultivo, indicando plasticidade fenotípica. Termos para indexação: Ananas comosus, ambiente de cultivo, micropropagação, aclimatação.
Preview · Article · Feb 2006 · Pesquisa Agropecuária Brasileira
[Show abstract][Hide abstract] ABSTRACT: As folhas de Gomphrena arborescens L.f., nativa do Cerrado, são utilizadas contra dismenorréia na medicina popular. As investigações morfológica, anatômica e histoquímica das folhas visam fornecer elementos para taxonomia, para controle de qualidade de drogas e identificação microscópica de fitoterápicos. Folhas foram coletadas em Brasília, DF, nas áreas de Cerrado do Centro Olímpico da Univesidade de Brasília e na Reserva Ecológica do IBGE. Foram efetuadas análises morfológicas, anatômicas e histoquímicas. Os estudos de arquitetura foliar, densidade estomática e de vênulas terminais foram efetuados em folhas diafanizadas, apresentando médias de 42,39±15,50 estômatos mm-2 e 11,7±3,55 vênulas terminaismm2. As folhas apresentaram duas formas de tricomas tectores. O mesofilo bilateral apresenta tecido clorenquimático disposto radialmente à bainha parenquimática completa que envolve os feixes vasculares, características da síndrome Kranz associada ao ciclo fotossintético C4. O amido concentra-se na bainha parenquimática. As folhas são ricas em celulose, drusas de oxalato de cálcio, proteínas, lignina e outros compostos fenólicos, entre eles os flavonóides. As folhas apresentam morfologia variável, mas o padrão anatômico e de venação são constantes.
Full-text · Article · Jun 2005 · Acta Botanica Brasilica
[Show abstract][Hide abstract] ABSTRACT: Cassava anatomical data are rare in literature. Despite of its economic value, less is found about the anatomical comparative study related to physiological aspects. The stem anatomy of an interspecific hybrid (Manihot esculenta x M. oligantha) and its tetraploid was studied. Hand cross sections were applied to stem, colored by safranin and alcian blue, and mounted in synthetic resin. The tetraploid form displayed larger medulla and absence of growth rings. Vascular tissues in the tetraploid were larger. Both forms had similar vessel elements and articulated laticifers. The nature of distribution of different tissues in the two types suggests drought resistance may be imparted to the tetraploid form.
[Show abstract][Hide abstract] ABSTRACT: This study describes the stem anatomy of Manihot esculenta Crantz and its hybrid with M. oligantha Pax. This is the first report of the presence of internal phloem in this genus. Cross-sections were made, fixed, conserved and colored by safranin-alcian blue. M. esculenta and its hybrid showed the same vascular structure in bicollateral bundles with internal phloem, which may be related to drought resistance and enables selection of individuals that are more adapted to arid regions.