Anatomia de folhas e raízes de Aechmea lindenii (E. Morren) Baker var. lindenii (bromeliaceae)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pos-Graduação em Biologia Vegetal, Florianópolis, 2009Aechmea lindenii (E. Morren) Baker var. lindenii (Bromeliaceae-Bromelioideae) ocorre em restingas e Floresta Pluvial de Encosta Atlântica em Santa Catarina e Nordeste do Rio Grande do Sul, BR. Pode ser encontrada total ou parcialmente exposta à irradiação solar e em distintas formas de vida - terrícola, rupícola e epifítica. Apresenta variações morfológicas (tamanho das folhas, coloração) em resposta à intensidade da irradiação solar. O objetivo deste trabalho foi comparar morfo-anatomicamente às características de folhas e raízes de A. lindenii var. lindenii em distintas condições ambientais. Foram coletadas, na Ilha de Santa Catarina (Florianópolis, SC), folhas de plantas terrícolas em restinga herbácea (alta irradiação solar), rupícolas de costões rochosos (alta irradiação solar), terrícolas e epifíticas de sub-bosques (baixa irradiação solar) de restinga arbórea e rupícolas de sub-bosque (baixa irradiação solar) de Floresta Pluvial de Encosta Atlântica. Foram feitas análises in vivo e testes histoquímicos. Amostras foram fixadas em glutaraldeído 2,5%, tampão fosfato de sódio 0,1M, pH 7,2, desidratadas em série etílica. Para microscopia óptica foram infiltradas em parafina e hidroxietilmetacrilado, coradas com azul de astra/fucsina básica ou azul de toluidina. Para microscopia eletrônica de varredura foram embebidas em éter e secas. Foram mensurados comprimento; largura; área; suculência; esclerofilia; teor de clorofila a e b; densidade estomática; comprimento e largura das células-guarda; espessuras da lâmina foliar e das estruturas constituintes. Foi determinado o número mínimo amostral dos dados quantitativos das folhas nas distintas condições e analisados com ANOVA ou Kruskal-Wallis e comparados por teste Tuckey ou dum. A folha é lanceolada, constituída por lâmina (com espinhos marginais) e bainha. A lâmina foliar tem epiderme uniestratificada, membrana cuticular espessada, paredes celulares anticlinais sinuosas e um corpo silicoso por célula. Tricomas peltados ocorrem em ambas as faces foliares e estômatos só na face abaxial, em regiões sulcadas. Subepidermicamente, há esclerênquima, hidrênquima, clorênquima, feixes vasculares e cordões de fibras extra-vasculares. Na bainha foliar há aerênquima com células estreladas e raramente ocorre clorênquima. A baixa irradiação solar determinou maior expansão da área foliar, decorrente do alongamento da lâmina. Lâmina e bainha foliares têm maior largura sob alta irradiação. A esclerofilia variou entre 0,018 e 0,029 g/cm². A suculência de plantas rupícolas sob alta irradiação é maior que nas demais condições analisadas. Os espécimes de A. lindenii var. lindenii em costões rochosos, além da alta irradiação, estão expostas diretamente a ventos, borrifos marinhos e calor potencializado pela rocha. Tais fatores podem influenciar resultando em maior reserva hídrica quando comparada às demais condições analisadas. O teor de clorofila a, b e total foi maior nas folhas de plantas sob baixa irradiação solar. A densidade estomática foi maior em folhas de plantas sob alta irradiação solar. A espessura foliar total foi menor em plantas terrícolas sob alta irradiação, porém não mostrou diferenças estatísticas significativas entre as outras condições. Os dados mostraram que o conjunto dos fatores ambientais determinam as variações entre as características morfo-anatômicas e fisiológicas de diferentes formas de vida de A. lindenii var. lindenii, sob alta e baixa irradiação solar. As raízes adventícias estão constituídas por epiderme, córtex e cilindro central. A epiderme é uniestratificada e possui pêlos absorventes, o córtex está constituído por parênquima externo, incluindo a exoderme, anel esclerenquimático, parênquima interno, com amplos espaços intercelulares, e endoderme, com espessamento em "O". O cilindro central é poliarco e a medula esclerificada. Não foram observadas diferenças qualitativas nas raízes adventícias das formas de vida terrícola, rupícola e epifítica. Aechmea lindenii (E. Morren) Baker var. lindenii (Bromeliaceae-Bromelioideae) occurs in restingas and Hillside Atlanticrain Forest in Santa Catarina and the Northeast of Rio Grande do Sul, BR. It can be found totally or partially exposed to solar irradiation and in different life forms - terricolous, rupicolous and epyphytes. It has morphological variation (leaves size, coloration) in reaction to the intensity of solar irradiation. The aim of this work was to compare the morpho-anatomically characteristics of the leaves and roots of A. lindenii var. lindenii in distinct environmental conditions. In Santa Catarina Island (Florianópolis, SC), the following were collected: leaves of terricolous plants in the herbaceous restinga (high solar irradiation), rupicolous of rocky coast (high solar irradiation), terricolous and epiphytes understorey (low solar irradiation) of arboreal restinga and rupicolous of understorey (low solar irradiation) of Hillside Atlanticrain Forest. Samples were fixed in 2.5 % glutaraldehyde, in phosphate 0.1 M sodium buffer, pH 7.2, dehydrated in ethanol graded series. For light microscopy foram included in paraffin and hydroxyethylmethacrylate, stained with basic fuchsin/astra blue or toluidine blue. For the Scanning Electron Microscopy were soaked in ether and dried. They were measured length; breadth; area; succulence; sclerophylly; teor of chlorophyll a and b; stomatic density; length and breadth of the guard-cells; width of the blade leaf and structure components. It was determined a minimum number of samples of the quantitative data of the leaves of the distinct conditions and analysis of ANOVA or Kruskal-Wallis and compared per Tuckey test or dum. The leaf is lanceolate, with blades (with marginal spines) and sheath. The blade has one-layer epidermis, thickened cuticular membrane, sinuous anticlinal cellular walls and one silica bodies per cell. Peltate scales occurs in both the leaves faces and stomata, only an abaxial face, in furrowed regions. Subepidermically, there is sclerenchyma, hydrenchyma, chlorenchyma, vascular bundles and strings of extravascular fibers. In the sheath there is aerenchyma with stellate cells and chlorenchyma rarely occurs. The low solar irradiation determined more expansions of the leaf area, due to the stretching of the blade. Leaf blade and sheath have more breadth under high solar irradiation. The sclerophylly varied between 0,018 e 0,029 g/cm². The succulence in rupicolous plants under high irradiation is larger than in the other conditions analyzed. The specimes of A. lindenii var. lindenii in rocky coast under high irradiation are directly exposed to wind, sea spray and heat which is potentialized by rock. These factors may influence and result in hydric store when compared to other conditions analyzed. The level of chlorophyll a and b and total was larger in the leaves of plants under low solar irradiation. The stomatic density was larger in the leaves of plan was smaller in high solar irradiation. The width of the total blade leaf was smaller in leaves of terricolous plants under high solar irradiation, nevertheless, statistically significant differences were not found among other conditions. The data shows that the group of environmental factors determines the variations amongs the morpho-anatomical and physiological characteristics of different life forms of A. lindenii var. lindenii, under high and low solar irradiation. The adventitious roots are made up of epidermis, cortex and central cylinder. The epidermis is one-layer and has root- hairs, the cortex is made up of outer parenchyma, sclerenchymatic ring, inner parenchyma, with intercellular spaces and endodermis, with thickened in "O". The central cylinder is poliarch and the pith is sclerified. Qualitative differences were not found in the adventitious roots of de life forms terricolous, rupicolous and epyphytes

Leaf morphoanatomy of rheophyte Dyckia distachya Hassler (Bromeliaceae)

This research reports on the leaf morphoanatomy of the rheophyte Dyckia distachya. Plants with young and mature leaves of three populations from the Pelotas River and Uruguay River (SC, Brazil), which were maintained in a greenhouse, were utilized in the study. The leaves of D. distachya have sheaths, and the blades are lanceolate with serrate margins. The leaf epidermis of this species has a thickened cuticular membrane; thickened and lignified cellular walls, except in the outer periclinal; and silica bodies in the lumen. Tetracytic stomata are found within individual depressions that are protected by peltate scales; both the stomata and scales are restricted to the intercostal zones, on the abaxial surface. These features of the epidermis suggest that this species has the ability to conserve water while gas is exchanged during periods when the water level is low. The mesophyll is formed by the following: the hypodermis, which is made of septate fibers (along the adaxial surface and abaxial costal regions) or sclereids (abaxial intercostal regions); hydrenchyma, the widest tissue; chlorenchyma, located adaxially to the collateral vascular bundles; and aerenchyma, which communicate directly with the stomata. The leaf sheath has neither scales nor stomata. Dyckia distachya has both xeromorphic and hydromorphic features, which are associated with survival during periods when the water level is low or is high, respectively.This research reports on the leaf morphoanatomy of the rheophyte Dyckia distachya. Plants with young and mature leaves of three populations from the Pelotas River and Uruguay River (SC, Brazil), which were maintained in a greenhouse, were utilized in the study. The leaves of D. distachya have sheaths, and the blades are lanceolate with serrate margins. The leaf epidermis of this species has a thickened cuticular membrane; thickened and lignified cellular walls, except in the outer periclinal; and silica bodies in the lumen. Tetracytic stomata are found within individual depressions that are protected by peltate scales; both the stomata and scales are restricted to the intercostal zones, on the abaxial surface. These features of the epidermis suggest that this species has the ability to conserve water while gas is exchanged during periods when the water level is low. The mesophyll is formed by the following: the hypodermis, which is made of septate fibers (along the adaxial surface and abaxial costal regions) or sclereids (abaxial intercostal regions); hydrenchyma, the widest tissue; chlorenchyma, located adaxially to the collateral vascular bundles; and aerenchyma, which communicate directly with the stomata. The leaf sheath has neither scales nor stomata. Dyckia distachya has both xeromorphic and hydromorphic features, which are associated with survival during periods when the water level is low or is high, respectively

Leaf Epidermis of the Rheophyte Dyckia brevifolia

Some species of Dyckia Schult. f., including Dyckia brevifolia Baker, are rheophytes that live in the fast-moving water currents of streams and rivers which are subject to frequent flooding, but also period of low water. This study aimed to analyze the leaf epidermis of D. brevifolia in the context of epidermal adaptation to this aquatic plant’s rheophytic habitat. The epidermis is uniseriate, and the cuticle is thickened. The inner periclinal and anticlinal walls of the epidermal cells are thickened and lignified. Stomata are tetracytic, located in the depressions in relation to the surrounding epidermal cells, and covered by peltate trichomes. While the epidermal characteristics of D. brevifolia are similar to those of Bromeliaceae species, this species has made particular adaptations of leaf epidermis in response to its rheophytic environment

Morfoanatomia foliar da reófita Raulinoa echinata R.S. Cowan - Rutaceae Leaf morphoanatomy of the rheophyte Raulinoa echinata R. S. Cowan - Rutaceae

Reófitas são espécies vegetais confinadas aos leitos de rios e riachos de fortes corredeiras, crescendo acima do nível das inundações, mas não além do alcance da ocorrência regular das rápidas enchentes. A morfoanatomia foliar de Raulinoa echinata R.S.Cowan (Rutaceae) foi investigada objetivando compreender a adaptação às peculiaridades do hábitat reofítico. As folhas de R. echinata são dorsiventrais e hipoestomáticas. A epiderme é uniestratificada e os estômatos são anomocíticos. As células-guarda estão dispostas acima do nível das demais células epidérmicas (característica hidromórfica), mas com átrio externo conspícuo (característica xeromórfica). Aspectos mais marcantes relacionados ao hábitat reofítico são estenofilia e presença de suberina nas paredes periclinais internas das células epidérmicas. A área foliar varia com a intensidade de exposição ao sol, a densidade estomática varia com o fluxo do rio; as espessuras dos tecidos do mesofilo variam com ambas condições. Ductos secretores e idioblastos com cristais de fosfato de cálcio ocorrem no mesofilo. Os dados revelaram plasticidade da estrutura foliar às condições peculiares do ambiente reofítico e as condições sombreadas ou expostas ao sol.<br>Rheophytes are plants confined to the beds of swift-running streams and rivers, growing above flood level but not beyond the normal reach of flash floods. Leaf morphoanatomy of the rheophyte Raulinoa echinata R.S.Cowan (Rutaceae) was investigated with a focus on understanding adaptation to the peculiarities of the rheophytic habitat. R. echinata leaves are dorsiventral and hypostomatic. The epidermis has a single layer of cells and the stomata are anomocytic. The guard cells rise above the level of the other epidermal cells (a hydromorphic characteristic), but with a conspicuous outer cavity (a xeromorphic characteristic). Prominent traits related to the rheophytic habitat are stenophylls and the presence of suberin on the inner periclinal walls of the epidermal cells. Leaf area varies with sun exposure while stomatal density varies with river flow. In R. echinata, mesophyll tissue thickness varies with light intensity and river flow. Secretory cavities and idioblasts with calcium phosphate crystals occur in the mesophyll. The data revealed leaf-structure plasticity in relation to the singular conditions of the rheophytic environment as well as to shade or sunlight