Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf anatomy of Pseudofrenelopsis sp. and B. obesum specimens is revisited, including the first report of some epidermal and vascular traits for both taxa from the Crato Formation. Along with its paleoecological significance, the new data suggest the presence of more than one Pseudofrenelopsis species in the Aptian taphoflora of the Araripe Basin and further support the taxonomic placement of B. obesum within Araucariaceae.

Mechanisms by which plants acclimatize to water deficit conditions can affect development and, especially in aromatic plants, the essential oil synthesis. To evaluate the effects of water deficit on Ocimum africanum, seedlings were exposed to water levels corresponding to 100, 80, 70 and 60% of the substrate field capacity. The different watering regimes corresponded to predawn water potentials of –0.5, –0.9, –1.6 and –1.9 MPa, respectively. Decreased stomatal conductance and increased glandular and tector trichome density were observed under water deficit. In addition, reductions in leaf gas exchange and water consumption under water deficit led to decreased plant height, numbers of leaves and inflorescences, and total biomass production. As a result, lower essential oil yield and water use efficiency for biomass production occurred in the -1.9 MPa treatment. The content and production efficiency of essential oil (quantity of oil produced per unit water consumed) were higher in the –0.9 and –1.6 MPa treatments. There were no significant differences among treatments in the chemical composition of essential oil, and the major component of essential oil in leaves and inflorescences was isoeugenol in all treatments. The 80% field capacity watering regime (branch water potential of –0.9 MPa) was best for the growth and production of essential oil in O. africanum, for the cultivation of aromatic plant under drought economically viable in the semi-arid climatic regions. Key words: Drought adaptation, essential oil, irrigation, water use efficiency.

As macrófitas aquáticas vêm sendo usadas no monitoramento de águas poluídas por metais pesados, dessa forma, avaliou-se a capacidade fitorremediadora de Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) e de Polygonum ferrugineum Wedd. (Polygonaceae). As duas espécies foram submetidas as concentrações 0, 25 e 50 mg L-1 de cádmio em solução nutritiva. Aos sete dias após a aplicação dos tratamentos, foram efetuadas medições de trocas gasosas foliares e de emissão de fluorescência da clorofila em folhas expandidas e maduras. Amostras de raiz, caule e folha foram fixadas em FAA 70, incluídas em historresina, seccionadas em micrótomo rotativo e submetidas a coloração com azul de toluidina a 1%. Determinou-se o teor de Cd nas amostras vegetais utilizando ICP-MS. Na nervura central da folha e na raiz de P. ferrugineum, a 50 mg L-1 Cd observou-se alterações nas lacunas do aerênquima. Além disso, a 50 mg L-1 Cd, verificou-se acréscimo de tricomas glandulares nas folhas e compactação do mesofilo. No caule de A. philoxeroides, a 50 mg L-1 Cd, os núcleos das células do córtex apresentaram formato elíptico e a 25 e 50 mg L-1 Cd, ocorreu diminuição de drusas em células da nervura central da folha. Os teores de Cd para A. philoxeroides foram maiores na raiz, seguido do caule e da folha. A taxa de fotossíntese líquida de P. ferrugineum foi mais afetada pelo Cd em comparação a A. philoxeroides. Não houve variação da atividade do fotossistema II (Fv/Fm) entre as duas espécies e os tratamentos com Cd. A. philoxeroides foi mais tolerante ao Cd do que P. ferrugineum, o que indica sua potencialidade para uso em programas de fitorremediação.

Inhibiting seedling vegetative growth may be a strategy for improving modulation against biotic and abiotic stresses after transplanting. The objective of this study was to evaluate morphological responses of yellow passion fruit (Passiflora edulis) seedlings to growth inhibition resulted from the application of an inhibitor of gibberellin biosynthesis. The experiment was carried out in a greenhouse using seedlings grown in 290 cm3 polyethylene tubes. At 40 days after emergence, trays containing the seedlings were immersed in solutions at concentrations of 0, 40, 80, 120 and 160 mg (Paclobutrazol) PBZ L-1 up to substrate saturation. These five treatments were laid out in a randomized block design with four replicates. At 15, 30 and 45 days after PBZ application (DAA), basal stem diameter was measured; at 45 DAA, stem diameter, individual leaf area, specific leaf area, root diameter and root volume were measured, lignin content and the anatomy of leaves, stems, and roots were analyzed. Triazole-induced anatomical alterations in stems, leaves and roots cause morphological traits and intensify the specific reagent staining of phenolic compounds and lignin in yellow passion fruit (Passiflora edulis) seedlings.

Realizou-se estudo com o objetivo de analisar as alterações na anatomia foliar de Gallesia integrifolia (Spreng) Harms e Schinnus terebinthifolius Raddi quando cultivadas em ambientes de sombra moderada ou densa, simulando as condições naturais encontradas em sistemas agroflorestais tradicionais do sul da Bahia, Brasil. Plantas das duas espécies, com aproximadamente um ano de idade, foram cultivadas em casa de vegetação sob quatro níveis de sombreamento (25%, 17%, 10% e 5%). Estudos anatômicos do limbo foliar foram realizados a partir de material incluído em parafina e seccionado em micrótomo rotativo. Os diferentes níveis de sombreamento ocasionaram alterações na estrutura do mesofilo de ambas as espécies, com diferenças significativas na espessura do parênquima paliçádico, limbo foliar, e densidade estomática. Nas condições em que o experimento foi realizado os resultados obtidos indicaram que G. integrifolia apresenta maior capacidade de aclimatação a ambientes de sombra moderada e densa do que S. terebinthifolius, sendo mais indicada para o cultivo em sistemas agroflorestais pré-estabelecidos.