How can the analysis of reserve dynamics after fire support the phenological insight of Bulbostylis paradoxa (Spreng.) Lindm (Cyperaceae)?

Carbohydrate reserves are an essential key to plant survival from disturbance. Therefore, studying the different storage organs and types of reserves makes it possible to understand the dynamics of singular plants such as Bulbostylis paradoxa (Spreng.) Lindm, which presents flowering triggered by fire in the Cerrado. Physiological response to fire frequency is detailed by measuring the plant's reserves after a fire disturbance and which carbohydrates are more available for its use. It was measured the concentrations of starch, amino acids, total soluble carbohydrates and soluble proteins in leaves (control), flowers (burning) and caudex of B. paradoxa, in unburned individuals (control), and burned individuals (annually and biennially, obtained 48 h and 15 days after fire). Starch concentrations increased at both fire frequencies in all parts of the plant, as did carbohydrate concentrations. In amino acids, an increase in the concentration of flowers from individuals burned biennially 48 h after fire was observed. The protein concentration showed a decrease in burned plants. Furthermore, the two burning frequencies and the days following the fire can influence the storage of such reserves.

Morphological responses and tolerance of a tree native to the Brazilian Cerrado Astronium fraxinifolium Schott to boron toxicity.

The indiscriminate use of fertilizers and chemical pesticides can lead to boron contamination of the soil. Decontamination in general is expensive and results in other impacts. Phytoremediation is a sustainable alternative for soil restoration. Astronium fraxinifolium Schott (Anacardiaceae) is a tree species native to the Cerrado that is considered to be a pioneer species and a selective xerophyte, and it has been widely used in the reforestation and restoration of degraded areas. This study set out to characterize the physiology and anatomy of A. fraxinifolium under different boron concentrations and to assess the tolerance and phytoremediation potential of the species. An experiment with a completely randomized design was conducted in a greenhouse. The carbon allocation and chlorophyll content of leaves of A. fraxinifolium were determined. Boron concentration and the species' tolerance index were calculated from root and shoot samples. Levels of amino acids, proteins, total carbohydrates, starch, phenolic compounds, and anatomical analysis were also measured. A. fraxinifolium showed tolerance to boron concentrations in the substrate and accumulated a greater amount of the element in the aerial part, showing its phytoextraction ability. No significant differences were found in the physiology of A. fraxinifolium; however, some anatomical changes were observed. In the leaves, there were changes in the thickness of the abaxial surface of the epidermis and palisade and spongy parenchyma, and total leaf thickness, and in the roots, there were changes in the thickness of the phloem, diameter of vessel elements, and number of vessel elements per square millimeter. However, boron did not interfere in the development and survival of A. fraxinifolium, which points to the possibility that the species has phytoremediation potential.

Anatomical characters and chemical profile of leaves of three species in Lauraceae family

ABSTRACT The Lauraceae family is widely distributed in tropical and subtropical climates, has more than 2500 species and in the taxonomic point of view, it is one of the most difficult families to identify species. The aim of this study was to analyze the leaf anatomy of three species of Lauraceae (Ocotea indecora (Schott) Mez, Nectandra barbellata Coe-Teix. and Endlicheria paniculata (Spreng.) J.F.Macbr.) and identify the chemical profile of essential oil extracted from the leaves by hydrodistillation method. The leaves of the three species were obtained in "Parque Estadual Intervales", Atlantic Forest, São Paulo state, Brazil. Samples of leaves were fixed, dehydrated, embedded in synthetic resin and sectioned for mounting histological slides for anatomical description of leaf tissues. The essential oil extracted by hydrodistillation method from dried leaves was analyzed by gas chromatography to establish its chemical profile. The leaves are hypostomatic, the epidermis in E. paniculata and N. barbellata present regular cells walls and irregular cells walls in O. indecora in both sides of epidermis. The three species present a dorsiventral mesophyll. Histochemical analyses presented lipid substances in secretory cavity and cuticle; starch, phenolic compounds and mucilage were observed in parenchyma cells of midrib and mesophyll. Ultra structural analyses demonstrated that trichomes in the species E. paniculata and O. indecora are shown only on the abaxial leaf face and species N. barbellata presented trichomes on both sides of the epidermis (abaxial and adaxial). Ocotea indecora essential oil revealed as main compound the bicyclogermacrene and N. barbellata the δ-cadinene. The species showed different morphological characters and different compounds of the essential oil, being these data useful for the differentiation of the species.

Germination and seedling morphology of four South American Smilax (Smilacaceae).

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 degrees C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.

Propagation studies in Smilax fluminensis Steud. (Smilacaceae) / Estudos de propagação em Smilax fluminensis Steud. (Smilacaceae)

Smilax L. species, popularly known in Brazil as salsaparrilha, have been used in folk medicine as tonic against rheumatism and as anti-syphilitic since the sixteenth century; however, until today, their roots have been explored in an extractive way. The aim of this study was to analyze the propagation of Smilax fluminensis aiming to meet the demand and to propose procedures for its sustainable management. It was analyzed the percentage of seed germination, rooting of aerial and subterranean stem cuttings and plant resprouting capacity after removal of the shoots. The monitoring lasted one year. Seeds were subjected to temperatures: 25°C, 30°C, 20-30°C and 20-35°C under a daily photoperiod of eight hours and in the absence of light. For rooting the stem cuttings, aerial and subterranean stems about 20cm long with two nodal regions were subjected to treatment with distilled water (control) and indolbutyric acid (IBA) at 100ppm. The best germination percentages obtained for S. fluminensis were 80 percent at 20-30°C under light and 85 percent at 30°C in the dark. Only subterranean stem cuttings showed significant difference concerning fresh and dry matter of roots with higher values in treatments with hormone compared to the control.

As espécies do gênero Smilax L., conhecidas popularmente como salsaparrilha, são empregadas na medicina popular como fortificante contra o reumatismo e antissifilítico desde o século XVI, porém até hoje as suas raízes são exploradas de maneira extrativista. O objetivo deste estudo foi analisar a propagação de Smilax fluminensis visando a auxiliar no atendimento da demanda e apontar propostas para o seu manejo sustentável. Foram analisados a porcentagem de germinação de sementes, o enraizamento de estacas de ramos aéreos e subterrâneos e o acompanhamento ao longo de um ano da capacidade de rebrotamento das plantas após a retirada dos ramos aéreos. As sementes foram submetidas às temperaturas: 25, 30, 20-30 e 20-35°C, sob fotoperíodo diário de oito horas e na ausência de luz. Para o enraizamento de estacas, foram utilizados ramos aéreos e subterrâneos com aproximadamente 20cm com duas regiões nodais submetidas ao tratamento com água destilada (controle) e com ácido indolbutírico (AIB) a 100ppm. As melhores porcentagens de germinação obtidas para S. fluminensis, 80 por cento em 20-30°C no claro e 85 por cento a 30°C no escuro. Apenas as estacas de ramos subterrâneos enraizaram, houve diferença significativa em relação à massa fresca e seca de raízes com valores maiores nos tratamentos com hormônio em relação ao controle.

Seed germination and seedling morphology of Smilax polyantha (Smilacaceae) / Germinação e morfologia de plântulas de Smilax polyantha (Smilacaceae)

Brazilians have been using the underground organs of Smilax species in alternative medicine since the 19th century because of their anti-rheumatic qualities. However, even nowadays, these species are explored only by extractivism. Studies on seed germination and development of these organs could be useful to preserve these plants. After germination, seedling development of Smilax polyantha was analyzed to understand underground stem formation. Furthermore, to analyze the ontogenesis of the underground system, seedlings aged from one to twelve months were sectioned. One of the most striking features of this species is the presence of two stem branching systems. The plumule gives rise to the first stem branching system with negative geotropism. Its first underground axillary bud sprouted into the other caulinar axis with positive geotropism. The horizontal growth and the subsequent thickening of this underground organ depended on the development of axillary buds from basal nodes of the previous branches. The cotyledonary bud did not play a role in the underground formation, as previously described in the literature for this genus, but the buds of the basal cataphylls built the second stem branching system. In this study we discuss the terminology and suggest calling this second stem branching system a rhizophore.

As espécies de Smilax L. são utilizadas na medicina popular brasileira desde o século 19 devido às propriedades anti-reumáticas atribuídas aos órgãos subterrâneos de todas as espécies. No entanto, ainda hoje, essas espécies são exploradas apenas por extrativismo. Estudos sobre a germinação e o desenvolvimento dos órgãos subterrâneos podem ser úteis para preservar essas plantas. Após a germinação, o desenvolvimento de plântulas de Smilax polyantha foi analisado para compreender a formação do sistema subterrâneo. Para a análise da ontogênese do sistema subterrâneo foram seccionadas plantas em diferentes estágios de desenvolvimento entre um e doze meses. Uma das características mais marcantes desta espécie é a presença de dois sistemas de ramificação caulinar. A plúmula dá origem ao primeiro sistema caulinar de ramificações com geotropismo negativo. As gemas axilares subterrâneas desse primeiro eixo caulinar originam o segundo eixo caulinar com geotropismo positivo. O crescimento horizontal e o espessamento do órgão subterrâneo dependem do desenvolvimento de gemas axilares de nós basais dos ramos anteriores. A gema cotiledonar não participa da formação do caule subterrâneo, como descrito anteriormente na literatura para este gênero, mas as gemas axilares basais dos ramos caulinares aéreos originam o segundo eixo de ramificação caulinar subterrâneo. Neste estudo, após ser discutida a terminologia mais adequada, sugere-se chamar o caule subterrâneo dessas espécies de rizóforo.