Leaf morphological strategies of seedlings and saplings of Rhizophora mangle (Rhizophoraceae), Laguncularia racemosa (Combretaceae) and Avicennia schaueriana (Acanthaceae) from Southern Brazil

Abstract

Abstract:The initial phase of a plant life cycle is a short and critical period, when individuals are more vulnerable to environmental factors. The morphological and anatomical study of seedlings and saplings leaf type enables the understanding of species strategies of fundamental importance in their establishment and survival. The objective of this study was to analyze the structure of seedlings and saplings leaf types of three mangrove species, Avicennia schaueriana, Laguncularia racemosa, Rhizophora mangle, to understand their early life adaptive strategies to the environment. A total of 30 fully expanded cotyledons (A. schaueriana and L. racemosa), 30 leaves of seedlings, and 30 leaves of saplings of each species were collected from a mangrove area in Guaratuba Bay, Paraná State, Brazil. Following standard methods, samples were prepared for morphological (leaf dry mass, density, thickness) and anatomical analysis (epidermis and sub-epidermal layers, stomata types, density of salt secretion glands, palisade and spongy parenchyma thickness). To compare leaf types among species one-way ANOVA and Principal Component Analysis were used, while Cluster Analysis evaluated differences between the species. We observed significant structural differences among species leaf types. A. schaueriana showed the thickest cotyledons, while L. racemosa presented a dorsiventral structure. Higher values of the specific leaf area were observed for seedlings leaves of A. schaueriana, cotyledons of L. racemosa and saplings leaves of A. schaueriana and R. mangle. Leaf density was similar to cotyledons and seedlings leaves in A. schaueriana and L. racemosa, while R. mangle had seedlings leaves denser than saplings. A. schaueriana and R. mangle showed hypostomatic leaves, while L. racemosa amphistomatic; besides, A. chaueriana showed diacytic stomata, while L. racemosa anomocytic, and R. mangle ciclocytic. Seedling leaves were thicker in R. mangle (535 µm) and L. racemosa (520 µm) than in A. schaueriana (470.3 µm); while saplings leaves were thicker in L. racemosa

Leaf traits and mineral contents of Rhizophora mangle L. subject to environmental pollution

“…Rhizophora mangle presents a dorsiventral, hypostomatic leaf with uniseriate epidermis and hypodermis. We found no differences in tissue composition between the leaves of the compared areas, corroborating information previously reported (Metcalfe and Chalk 1950;Silva et al 2015;Pelozo et al 2016). Stomata located only on abaxial surface is a common trait of many angiosperms exposed to sunlight.…”

Rapid detection of metals in red mangrove Rhizophora mangle leaves in a polluted environment in Brazil

“…Rhizophora mangle presents a dorsiventral, hypostomatic leaf with uniseriate epidermis and hypodermis. We found no differences in tissue composition between the leaves of the compared areas, corroborating information previously reported (Metcalfe and Chalk 1950;Silva et al 2015;Pelozo et al 2016). Stomata located only on abaxial surface is a common trait of many angiosperms exposed to sunlight.…”

Extrativismo E Aproveitamento De Lianas Na Cadeia Produtiva Do Artesanato: Uma Revisão Integrativa

“…Estudos sobre o estabelecimento de plântulas em regiões tipicamente salinas ainda são escassos, como por exemplo, em áreas de mangue. Os manguezais são ecossistemas de transição que ocorrem nas zonas costeiras e entremarés, típicos de regiões tropicais e subtropicais (PELOZO et al, 2016;LE MINOR et al, 2019). As plantas de mangue são tolerantes a salinidade, mas pouco se conhece sobre as estratégias para o estabelecimento de suas plântulas.…”

“…As plantas de mangue são tolerantes a salinidade, mas pouco se conhece sobre as estratégias para o estabelecimento de suas plântulas. Estudo realizado por Pelozo et al (2016), com as espécies Avicennia schaueriana, Laguncularia racemosa e Rhizophora mangle presentes em mangue de Guaratuba, PR, analisando as folhas e cotilédones das plântulas, verificou a presença de ajustes morfológicos para reduzir a perda de água, como a presença de cutícula e hipoderme espessa e eliminação do excesso de sal, através da ocorrência de glândulas de sal. Assim esses traços possibilitaram maior eficiência para a manutenção dos processos fisiológicos durante o estabelecimento inicial das plântulas.…”