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Blueberry (Vaccinium spp.) cultivation has experienced a notable increase both for its good organoleptic characteristics and the nutritional and functional properties of this berry. The aim of this study was the physicochemical characterization of blueberry juices obtained from 55 blueberry cultivars grown under the same environmental conditions for 2–4 years. The results provide a broad and robust database, both for the number of cultivars and the periods of monitoring thereof, in order to cover different aspects of blueberry processing, and more specifically, production of juices. Blueberries belonging to V. virgatum cultivars showed the higher values of total anthocyanin content, total phenolic content, antioxidant activity, soluble solids, and pH, and V. corymbosum cultivars the higher level of titratable acidity. Results also showed a high variability among cultivars. Observed variations can be used in plant breeding and classification of blueberry cultivars, at least, at the species level.

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The diversity of fungal endophytes is poorly known and particularly in the case of Nicotiana tabacum, the literature is limited. The present study assessed and compared the diversity and distribution of endophytic fungi between different organs of tobacco plants. We calculated the relative frequency and rates of colonisation and of isolation of endophytic fungi in roots, stems and leaves, as well as the Shannon–Wiener and Simpson diversity indexes. Similarities between assemblages from the studied organs were also analysed. A total of 1588 endophytic fungal strains assigned to 31 morphospecies were isolated. The highest diversity of endophytes was found in leaves, being Fusarium graminearum and Alternaria botrytis the most common fungal species. This study provides information on the distribution of fungal endophytes inhabiting leaves, stems, and roots of N. tabacum and thus can serve as a starting point for increasing our comprehension on the interactions in which these fungi are involved.

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Community Ecology
Authors:
J. Madrigal-González
,
J. García-Rodríguez
,
A. Puerto-Martín
,
B. Fernández-Santos
, and
P. Alonso-Rojo

In arid and semi-arid ecosystems, the presence of woody neighbours affects the existence of several herbaceous species by modifying critical aspects of the environment (e.g., soil humidity, nutrient content or light availability) beneath their canopies. Herbaceous species growing in the understory of Pinus pinaster may be distinct from those in open areas due to litter fall, light interception and changes in nutrient availability. We suggest that the overall effect of woody neighbours on herbaceous layer diversity may vary with the scale focus of analysis. To examine this hypothesis, we collected data on the abundance of herbaceous species in open pineland forests of the central Iberian Peninsula (Spain) using sample quadrats of 0.5 m × 0.5 m distributed beneath, at the edge, and outside the canopy of pines in a landscape composed of dunes and plains. The results of CCA ordination revealed significant spatial segregation of herbaceous species reflecting the occurrence of pines and dunes in the landscape. Nested ANOVA disclosed markedly lower species richness beneath the pines, particularly in the dune sites. Species richness partitioning showed higher pine-induced heterogeneity than expected from the sample-based randomized model, leading to significantly increased species richness at the patch level. Hence, the outcome of pine-induced effects on the herbaceous plant diversity is scale-dependent, negative if we focus on separate communities, but positive if the scale focus is extended to whole patches comprising the sum of communities beneath, at the edge, and outside pine tree canopies. These results emphasize the necessity of using various scale perspectives to clarify the different ways in which pines and other woody nurse species affect structure of herbaceous communities in semi-arid Mediterranean ecosystems.

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Bisphenol A (BPA), bisphenol A dimethacrylate (BisDMA) and phthalic acid (PA) endocrine disruptors can migrate from the plastic lining of cans to foods producing serious health problems when they exceed allowable concentration limits for consumption. In this work, a method was assessed for the determination of BPA, BisDMA, and PA in vegetable food cans from Mexico using a food simulant. Those disruptors were determined by HPLC connected to an Evaporative Light Scattering Detector (ELSD), and simultaneous detection by UV-Vis detector was used for validation. The most frequently found disruptor in major concentration was PA over the range of 5.40 to 112.39 μg l−1. The samples analysed did not exceed the migration limit accepted by the US-FDA and US-EPA for bisphenols. Our results showed that HPLC-ELSD produces chromatograms with accurate signals and smaller detection limits than the UV-Vis detector for the substances analysed here.

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The use of melatonin as antioxidant has been extensively established. But what would the antioxidant function be if one were to go one step back in the anabolism of that amine, and orally administer its precursor — the amino acid tryptophan? Diurnal animals ( Streptopelia roseogrisea ) were administered orally capsules containing 125 or 300 mg L-tryptophan/kg b.w. for 7 days at the end of the light period (20 h ). A control group received capsules with methylcellulose. The antioxidant function was studied through the reduction of nitroblue tetrazolium (NBT) by superoxide anion, and through the levels of malonaldehyde (MDA) produced in the lipoperoxidation that occurs from the respiratory burst in response to the presence of a foreign particle in phagocytic cells (heterophils), which were extracted at 2 h — at the acrophase of melatonin in the blood stream. In the heterophils extracted from the group that received 125 mg kg −1 b.w. tryptophan, there was less oxidative stress as determined by the NBT reduction than in those from the 300 mg kg −1 b.w. group. In the study of the lipoperoxidation of the membranes as determined by the levels of MDA, however, no significant variations were observed between the different groups. The lower concentration (125 mg L-tryptophan/kg b.w.), administered orally, succeeded in diminishing the free radicals produced in the heterophils for the destruction of the ingested foreign agent, but not fully or maximally. The possible solution to this prooxidant/antioxidant imbalance would be to administer a lower concentration of tryptophan to attain the perfect balance for application in nutritional treatments.

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Community Ecology
Authors:
F.A. Rodríguez-Zaragoza
,
M. Ortiz
,
F. Berrios
,
L. Campos
,
A. de Jesús-Navarrete
,
J. Castro-Pérez
,
A. Hernández-Flores
,
M. García-Rivas
,
F. Fonseca-Peralta
, and
E. Gallegos-Aguilar

Banco Chinchorro is the largest reef in the Mexican Caribbean. Historically, spiny lobster, queen conch and over 20 other reef species have been exploited here. Multispecies intervention management from an ecosystem perspective has been developed in this area; however, an assessment of the effects of such practices on ecosystem health is required. Five quantitative trophic models were constructed using Ecopath with Ecosim. The results show that, in terms of biomass, benthic autotrophs are the dominant group in all communities. Ecosystem Network Analysis indices showed that Cueva de Tiburones was the most mature, developed, complex and healthy subsystem, but, El Colorado and La Baliza were the subsystems most resistant to disturbances. The fisheries mainly concentrate on primary (La Baliza and Cueva de Tiburones sites) and secondary consumers (La Caldera, Chancay, and El Colorado). The greatest propagation of direct and indirect effects, estimated by Mixed Trophic Impacts and Ecosim simulations, were generated by the benthic autotrophs, small benthic epifauna, benthic-pelagic carnivorous fish and benthic carnivorous fish, among others. In contrast, the System Recovery Time showed different patterns among subsystems, indicating several compartments that reduce resilience. Considering the structure, dynamics, trophic functioning and ecosystem health of Banco Chinchorro, its ecological heterogeneity highlights the need for the design of a specific (by subsystem) management strategy, particularly because different species or functional groups present greater sensitivity to human interventions in each community.

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Community Ecology
Authors:
B. Hermosillo-Nuñez
,
F. Rodríguez-Zaragoza
,
M. Ortiz
,
C. Galván-Villa
,
A. Cupul-Magaña
, and
E. Ríos-Jara

The spatial distribution and abundance of the seven most abundant species of echinoderms (Diadema mexicanum, Centrostephanus coronatus, Eucidaris thouarsii, Isostichopus fuscus, Pharia pyramidatus, Phataria unifascialis and Acanthaster ellisii) were evaluated in coral communities of Isla Isabel National Park (Mexico). Biological (corals and other benthic groups) and physical (rocks and boulders) structural elements of the habitat were evaluated to determine their relationship to these species. Our results show that species composition and abundance varied among sampling sites and between seasons. Also were obtained significant differences in the echinoderm assemblage among sites across seasons. Similar results were detected for the environmental variables related to benthic habitat structure. D. mexicanum, P. unifascialis, E. thouarsii and C. coronatus were the main contributors to the species abundance and distribution in Isla Isabel. Most echinoderm species were positively related to the coverage of different coral species, algae and various types of benthic organisms as well as to physical benthic variables. These outcomes suggest that the spatial distribution and abundance of these echinoderms are explained by the habitat structure, which should be used to design conservation and management strategies for coral communities.

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