Screening chloroplast regions in <Emphasis Type="Italic">Calophyllum brasiliense</Emphasis> (Calophyllaceae) for suitability for population genetic analyses

The uniparental inheritance and conserved structure of the chloroplast genome among many angiosperms makes it suitable for constructing gene lineages and inferring population histories based on these relationships. However, the analysis of a single chloroplast region to solve population issues has not yielded the desired amount of variability due to the low mutation rate. Therefore, it is necessary to screen and carefully analyze chloroplast intergenic or intronic regions to select the most appropriate for studying the genetic variability in the chloroplast genome of a particular taxon. In this context, the aim of this work was to characterize 8 regions in Calophyllum brasiliense using 11 selected primer pairs and to evaluate their usefulness for phylogeographic analysis. Intergenic spacers petA-psbJ, petG-trnP and rpl32-trnL and the trnL intron demonstrated potentially informative sites. The combination of these 4 regions will allow the analysis of genetic population structure and the integration of historical aspects to inform strategies for conserving C. brasiliense, especially for highly impacted populations and those at risk of local extinction.     

Influence of Sulfonation of Inert Macroporous and Macronet Resins on the SO<Subscript>2</Subscript> Adsorption Capacity

The influence of sulfonation of both macroporous and hyper-cross-linked polystyrenic polymers on their adsorption capacity for SO₂ removal from residual gases was studied through equilibrium experiments and microstructural analysis. The results showed that the insertion of functional sulfonic active groups leads to a decrease of adsorption capacity of macroporous and macronet resins mainly due to decreasing of specific surface area of the resins. The results were compared with those obtained for powdered activated carbon, which has an adsorption capacity higher compared with that of macroporous resins and lower than those of macronet resins. The high adsorption capacity of macronet resins has been attributed to the advanced cross-linking of the polystyrene chains that leads to the formation of a three-dimensional network with a high specific surface area. The fitting of the experimental data on the typical adsorption isotherms (Langmuir and Freundlich) highlighted the surface heterogeneity of macroporous and macronet resins.     

Variation in reproductive phenology in a Pinus patula seed orchard and risk of genetic contamination from nearby natural stands

New Forests - Genetic variation in reproductive phenology among clones in a seed orchard affects the genetic efficiency of the orchard. Our objective was to evaluate genetic variation in...     

Post-cyclic transmission in Acanthocephalus tumescens (Acanthocephala: Echinorhynchidae)

The aim of this study was to investigate the post-cyclic transmission of Acanthocephalus tumescens (von Linstow, 1896) from Galaxias maculatus Jenyns to Oncorhynchus mykiss (Walbaum). Wild G. maculatus naturally infected with A. tumescens were fed to cultured rainbow trout, which were sacrificed at the second, third and fourth weeks post infection. Normally attached male and female acanthocephalans were recovered alive from the intestine of rainbow trout. Parasites survive at least four weeks post infection, growing and attaining full sexual maturity. Prevalence and mean intensity generally decreased after infection. A. tumescens is the eighth acanthocephalan species in which post-cyclic transmission has been proven.     

Simultaneous determination of benzimidazole fungicides by HPLC on apples,pears and their pulps

The simultaneous HPLC determination of carbendazim, thiabendazole and thiophanate-methyl in apples, pears and their pulps is described. The method is based on a clean-up procedure carried out on an Extrelut 20 cartridge followed by HPLC analysis on a Diol column using hexune+isopropanol as mobile phase. Average recoveries of 83.8% for carbendazim, 82.9% for thiabendazole and 68.8% for thiophanate-methyl on apple matrix were obtained; recoveries on pear matrix were in the same range. Detection limits with UV detection at 285 nm of 100 ng ml^?1 for carbendazim, 140 ng ml^?1 for thiabendazole and 500 ng ml^?1 for thiophanate-methyl were achieved.     

Differences in wound-induced changes in cell-wall peroxidase activities and isoform patterns between seedlings of Prosopis tamarugo and Prosopis chilensis

We determined changes in cell-wall peroxidase activities and isoform patterns in response to wounding in seedlings of Prosopis tamarugo Phil. (an endemic species of the Atacama Desert) and Prosopis chilensis (Mol.) Stuntz (a native species of central Chile), to assess tolerance to predation. In seedlings of both species, the maximal increase in peroxidase activity occurred 48 h after wounding, reaching three times the control value in P. tamarugo and twice the control value in P. chilensis. The activity of ionically bound cell-wall peroxidases increased only locally in wounded embryonic axes, whereas the activity of soluble peroxidases increased systemically in unwounded cotyledons. Analysis of ionic peroxidases by isoelectrofocusing revealed two groups of peroxidases in the cell walls of both species: four distinct acidic isoforms and a group of basic isoforms. In response to wounding, there was a large increase in activity of the acidic isoforms in P. tamarugo, whereas there was an increase in the activity of the basic isoforms in P. chilensis. In P. chilensis, the wound-induced increase in activity of the basic isoforms corresponded with one of the two isoforms detected in P. tamarugo prior to wounding. Experiments with protein and RNA synthesis inhibitors indicated that a preexisting basic peroxidase is activated in P. chilensis after wounding. Assays of ionically bound peroxidase activity with four different substrates corroborated the differences found in isoform patterns between species. In P. tamarugo, the largest increases in activity were found with ortho-phenylenediamine and ferulic acid as substrates, whereas in P. chilensis the largest increase in activity was found with guaiacol as substrate. Because the same basic cell-wall peroxidase that accumulated after wounding in P. chilensis was present in P. tamarugo prior to wounding, and the activity of acidic cell-wall peroxidases increased after wounding in P. tamarugo but not in P. chilensis, we conclude that P. tamarugo is more tolerant to wound stress than P. chilensis.     

Measurement of nuclear DNA content of the genus <Emphasis Type="Italic">Trifolium</Emphasis> L. as a measure of genebank accession identity

The collection, identification and maintenance of genebank accessions of the genus Trifolium is a major task because of the large number of genera and their occasional morphological similarity. We investigated whether the measurement of nuclear DNA content can serve as an additional criterion for identification of mislabeled accessions. Relative nuclear DNA content was determined by flow cytometry measurements for a total of 151 genebank accessions of 23 Trifolium species with notable agronomical value. Among 23 species analyzed, 15 were found to possess a uniform relative nuclear DNA content, with intraspecific variability of the majority of analyzed species lower than 5%. Within six Trifolium species, 1–2 atypical accessions with outstanding differences in relative DNA content, chromosome number and morphological features were found. In T. hybridum and partially in T. ambiguum these outstanding differences could be ascribed to variations in accession ploidy level. For the remaining atypical accessions, the determined nuclear DNA content, chromosome number and morphological features were not related to those characteristic of the species. Additionally taxonomic identity of atypical accessions was determined using ITS region sequencing and morphological observations. We propose flow cytometric measurements of nuclear DNA content as simple and reliable technique which can be used at seedling stage to verify identity and genetic stability of Trifolium genebank accessions.     

Hexavalent Chromium Removal by a Trichoderma inhamatum Fungal Strain Isolated from Tannery Effluent

A fungal strain possibly capable of removing hexavalent chromium was to be isolated from industrial effluent from a leather factory located in the city of Guadalajara, state of Jalisco, Mexico. The strain was identified as Trichoderma inhamatum by the D1/D2 domain sequence of the 28S rDNA gene. Batch cultures of T. inhamatum in media containing initial Cr(VI) concentrations from 0.83 to 2.43 mM Cr(VI) were prepared. Experimental results suggest that the fungus is capable of transforming hexavalent chromium to trivalent chromium; a transformation of a highly toxic contaminant to a low toxic form. The specific and volumetric rates of Cr(VI) reduction by T. inhamatum cultures decreased as the initial Cr(VI) concentration increased. The fungus exhibited a remarkable capacity to tolerate and completely reduce Cr(VI) concentrations up to 2.43 mM. These results indicate that the T. inhamatum fungal strain may have potential applications in bioremediation of Cr(VI)-contaminated wastewaters.     

Utilization of Wastes from the Coke-Chemical Production and Sewage Sludge as Additives in the Brick-Clay

Current modern building technologies use a greater variety of building materials and elements of these. Lately, intensive work has been done on investigating possibilities for using different wastes as additives in the production of new ceramic building products. This demonstrates that the raw material base can be enlarged and some environmental problems solved.The present work investigates the possibility of combined utilization of sludge from the Sofia wastewater treatment plant and waste products from coke-chemical production as additives to brick clay. The most appropriate combinations and concentrations of the materials used, and the means of preparing and firing the brick masses are determined. The strength characteristics of the resulting products are studied. The results obtained are useful in showing possibilities for the solution of environmental problems.