Anatomy and micromorphometry of Caryocar brasiliense leaves

Abstract

The current study aims to study the anatomy and micromorphometry of C. brasiliense leaves in three Cerrado (savanna) vegetation-types: dense, typical and sparse) -in the municipality of Porto Nacional-TO. Samples were collected, fixed and stored in alcohol 70%. Transverse, longitudinal and paradermal sections of the median leaflet were prepared for anatomical and micromorphometric studies using standard techniques. C. brasiliense leaflets show uniestratified epidermis covered by thick cuticle on the adaxial surface and by paracytic stomata and multicellular non-glandular trichomes on the abaxial surface. The mesophyll is formed by two or three layers of palisade parenchyma adaxially and spongy parenchyma abaxially. The vascular bundle is of the collateral type and the accessory bundles show a sheath extending into the epidermides. The micromorphometric analyses pointed to significant differences in the thickness of both adaxial epidermis and spongy parenchyma in all specimens from the three vegetation-types. The highest averages were found in the leaflets of sparse cerrado plants, suggesting that environmental factors may have an influence over the plants morphological responses. Key words: Caryocaraceae, Micromorphometry, Pequi, Morphology. ResumoO objetivo do trabalho foi caracterizar anatômica e micromorfometricamente folhas de C. brasiliense em três fitofisionomias do Cerrado (denso, típico e ralo), no município de Porto Nacional-TO. Amostras foram coletadas, fixadas e armazenadasestocadas em álcool 70%. Utilizando técnicas usuais para estudos em anatomia vegetal, foram obtidas secções transversais, longitudinais e paradérmicas do folíolo mediano para estudos anatômicos e micromorfométricos. Os folíolos de C. brasiliense apresentaram epiderme uniestratificada, recoberta por cutícula espessa na face adaxial e por estômatos paracíticos e tricomas tectores pluricelulares na face abaxial. O mesofilo é formado por duas a três camadas de parênquima paliçádico na face adaxial e esponjoso na abaxial. O feixe vascular é do tipo colateral, com demais feixes acessórios apresentando bainha que se estende até a epiderme. As análises micromorfométricas revelaram diferenças significativas na espessura da epiderme adaxial e do parênquima esponjoso em todas as plantas estudadas para cada uma das três fitofisionomias, sendo as médias mais elevadas encontradas nos folíolos das plantas crescendo em Cerrado esparso. Isto sugere que a influência de fatores ambientais pode ter modulado respostas morfológicas nas plantas. Palavras-chave: Caryocaraceae, Micromorfometria, Pequi, Morfologia.

Leaf morphology and anatomy of Richterago discoidea (Asteraceae): a taxonomic and ecological approach

“…; Ramos et al. ). The trichomes in R. discoidea , especially in the main vein region of the leaf blade, may be a protective factor against dryness.…”

“…It is noteworthy that, in environments with recent fire events, the individuals are shrubs (stems with woody branching), as occurred in Mucugê and Palmeiras. The habit variation of R. discoidea is probably related to the substrate and may represent strategies to overcome unfavorable conditions and keep producing new generations (Gardoni et al 2007;Scatena et al 2004;Silveira et al 2015;Ramos et al 2015). The epidermal cells are straight and thick in the populations collected at altitudes 861-1,021 m. The epidermal cells are predominantly sinuous, not thick, in areas at altitudes from 1,131 to 1,278 m (Table 3).…”

“…Stomata position is influenced by environmental factors such as CO 2 levels (Evert ), air humidity, water availability and light incidence on the leaf blade (Melo‐Junior & Boeger ; Ramos et al. ; Santiago et al. ).…”

“…The presence of a dorsiventral mesophyll with loose (larger braciform projections) and dense (compact cells) spongy parenchyma should influence anatomical responses to light levels (Melo‐Junior & Boeger ; Ramos et al. ; Rossatto et al. ; Sabbi et al.…”

“…; Dickison ; Guerra & Scremin‐Dias ; Melo‐Junior & Boeger ; Ramos et al. ; Rossatto et al. ; Silva et al.…”