Floral nectar production and nectary structure of a bee-pollinated shrub from Neotropical savanna

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adequação territorial com abordagem multicriterial pela análise da combinação linear ponderada

From the characterization of biophysical attributes of the watershed (slope, soil types, capacity to land use and land cover), this article, used the multi-criteria analysis method – Weighted Linear Combination, defined priority areas for adaptation to the use of land as to its capacity of use. With this methodological approach, were created for the watershed under study, four classes, formed by different combinations of biophysical attributes (discrete data), representing levels of priorities for agricultural land use. The Multicriteria Evaluation in a GIS is suitable for the mapping of priority areas to the suitability of land use in watersheds. The geospatial information on the biophysical environment, generated from the methodological procedures described in this article, has a high positive potential to guide the rational planning of the use of natural resources and territorial occupation, besides serving as a powerful instrument to guide policies and collective processes of decision on the use and land cover.

Is Drosera meristocaulis a pygmy sundew? evidence of a long-distance dispersal between Western Australia and northern South America

Background and aims South America and Oceania possess numerous floristic similarities, often confirmed by morphological and molecular data. The carnivorous Drosera meristocaulis (Droseraceae), endemic to the Neblina highlands of northern South America, was known to share morphological characters with the pygmy sundews of Drosera sect. Bryastrum, which are endemic to Australia and New Zealand. The inclusion of D. meristocaulis in a molecular phylogenetic analysis may clarify its systematic position and offer an opportunity to investigate character evolution in Droseraceae and phylogeographic patterns between South America and Oceania. Methods Drosera meristocaulis was included in a molecular phylogenetic analysis of Droseraceae, using nuclear internal transcribed spacer (ITS) and plastid rbcL and rps16 sequence data. Pollen of D. meristocaulis was studied using light microscopy and scanning electron microscopy techniques, and the karyotype was inferred from root tip meristem. Key Results The phylogenetic inferences (maximum parsimony, maximum likelihood and Bayesian approaches) substantiate with high statistical support the inclusion of sect. Meristocaulis and its single species, D. meristocaulis, within the Australian Drosera clade, sister to a group comprising species of sect. Bryastrum. A chromosome number of 2n = approx. 32–36 supports the phylogenetic position within the Australian clade. The undivided styles, conspicuous large setuous stipules, a cryptocotylar (hypogaeous) germination pattern and pollen tetrads with aperture of intermediate type 7–8 are key morphological traits shared between D. meristocaulis and pygmy sundews of sect. Bryastrum from Australia and New Zealand. Conclusions The multidisciplinary approach adopted in this study (using morphological, palynological, cytotaxonomic and molecular phylogenetic data) enabled us to elucidate the relationships of the thus far unplaced taxon D. meristocaulis. Long-distance dispersal between southwestern Oceania and northern South America is the most likely scenario to explain the phylogeographic pattern revealed.