The Euphorbiaceae family is the second most representative in the Caatinga biome. It presents a great taxonomic complexity, which requires the observation of other characters to support the identification of its taxa, such as pollen morphology. This study aims to describe the pollen morphology of Euphorbiaceae species occurring in the Serra Branca/Raso da Catarina Environmental Protection Area, Jeremoabo, Bahia, Brazil. The pollen material was obtained from exsiccates deposited in the Herbarium of the State University of Bahia, Campus VIII, Paulo Afonso, Bahia. The pollen grains were subjected to acetolysis, measured, described and photomicrographed under optical microscope; they were also metallized and observed under scanning electron microscopy. In total, 17 species were studied, with nine pollen descriptions unpublished. The species analyzed presented pollen grains that varied from small to very large, inaperturate, 2-3-porate, 3-colporate to pantoporate, with psilate and reticulate exine, and most of them with a Croton pattern. The characteristics found in this study are important for palynological knowledge, as well as assisting palynotaxonomic studies of the Euphorbiaceae family and providing a basis for future ecological and conservation research for Caatinga plants.
work aims to understand the physiological, histological and developmental status of soybean plants grown in soil contaminated by diesel oil. The pot experiment consisted of farming the cultivars of soybean, Pot & ecirc;ncia and NS6700, grown on substrate with diesel oil contaminant in doses of 0, 1, 4, and 8 mL L-1. The polynomial models fitted to the data set of growth and development of plants at the age of thirty days did not fail to describe adequately impressive potential of diesel oil at the highest level to quickly decline CO2 assimilation rate (22.50 to 7.50 & micro;mol m-2s-1 and from 17.50 to 7.55 & micro;mol m-2s-1) leaf transpiration (5.25 to 3.10 mmol H2O m-2s-1 and from 5.10 to 3.50 mmol H2O m-2s-1) and water use efficiency (4.50 to 2.25 mu mol CO2 mmol H2O-1 and from 3.75 to 2.15 mol CO2 mol H2O-1) in the cultivars, Pot & ecirc;ncia and NS6700 respectively. The multivariate fit, EUW=4.30-0.90LT+0.01RPD-0.01RXD-0.15GS+0.20A, predicted accurately how the traits, leaf transpiration, diameter of xylem and phloem of root tissues, stomatal conductance and CO2 assimilation rate, interacted each other's to determine water use efficiency by of soybean and alleviate harmful effects of increasing levels of diesel oil in the soil.
Bipinnula polysyka is herein reported for the first time for the Brazilian Flora. This rare and inconspicuous terrestrial orchid species was previously known from Uruguay and Buenos Aires Province, in Argentina. In the Brazilian State of Rio Grande do Sul, it grows in the open grasslands of the Pampa Biome, which are normally used for cattle grazing. Here, we describe and illustrate the found specimen and provide an extension of its known distribution range. Additionally, we offer a brief discussion on the morphological diagnosis and ecological aspects ofthis species.
Allelopathy is defined as the interference of one plant in the other through the release of allelochemicals in the environment. This work evaluated the allelopathic influence ofAlternanthera tenella on the germination and initial development ofLactuca sativa, Digitaria insularis, Emilia fosbergii and Portulaca oleracea, as well as to quantify and determine the phenolic compounds by High Performance Liquid Chromatography. Five leaf and root concentrations of the donor plant were tested using multi-well plates as containers in which 15 seeds were sown in six replications. The data obtained were subjected to analysis of variance and different inhibitory effects were observed, depending on the recipient species and the concentration used, with Emilia fosbergii and Digitaria insularis being the most sensitive species to leaf and root allelochemicals, respectively. Caffeic acid was identified in greater quantity, probably responsible for the effect on germination and initial development of recipient plants.
The objective of this study was to evaluate the stomatal density and glandular trichomes as well as the morphometry of stomata of Aloysia citriodora leaves submitted to different water availability throughout the seasons. The experiment was carried out in a greenhouse under a randomized block design, composed of four water availability (25%, 50%, 75%, and 100% of the field capacity) throughout the four seasons (autumn, winter, spring, and summer). We evaluated stomatal density and glandular trichomes, and stomatal morphometry (stomata length and width and stomata area). Stomatal density and stomatal morphometry were affected by the seasons, while water availability affected the glandular trichomes density throughout the seasons. There is a higher stomatal density in the spring, and lower in the winter. Winter and spring presented greater stomata length and stomata area. Glandular trichomes density increases in winter and summer under low water availability, with a higher density in the abaxial epidermis.
