State of Contamination of the Waters in the Guadiamar Valley Five Years after the AznalcÓllar Spill     

M. OlÍas  J. C. Cerón  I. Fernández  F. Moral  A. RodrÍguez-RamÍrez 《Water, air, and soil pollution》2005,166(1-4):103-119

In April 1998, the Aznalcóllar mine tailings dam spilled 2 hm³ of slurry and 4 hm³ of acid waters into the Agrio River (affluent of the Guadiamar River). The pollutants reached the proximity of the Doñana National Park, 60 km downstream. The state of contamination of groundwaters and surface waters, from several samplings made subsequent to the spill, is described. Although the Guadiamar valley groundwaters remain contaminated, this situation cannot be attributed to the mining spill, but to the long history of pollution from mining activity at Aznalcóllar. Three zones can be distinguished: the most polluted zone, with pH values close to 4 and very high concentrations of metals (up to 18 mg/l of Al and 7 mg/l of Mn) and sulfates (up to 1263 mg/l); a second zone where pH values are higher (close to neutral) and, as a result, the concentration of metals is significantly lower; and a third zone, with pH exceeding 7, in which the concentration of metals has already fallen to normal levels but sulfate concentrations remain high (above 500 mg/l). The waters of the Agrio River present characteristics similar to those of the most-polluted groundwaters; on mixing with the waters of the Guadiamar River they are neutralized, precipitating firstly Al and then the rest of the metals. These metals remain deposited on the river-bed, where they are readily remobilized in later spates. Analysis of changes in groundwater quality shows a trend toward a lower content of Zn and the other metals in most wells.  相似文献   

Yield development in potatoes as influenced by cultivar and the timing and level of nitrogen fertilization     

I. De la Morena  A. Guillén  L. F. García del Moral 《American Journal of Potato Research》1994,71(3):165-173

Path-coefficient analysis based on an ontogenetic model was used to study the relationships between tuber yield and yield components as influenced by cultivar and nitrogen fertilization. Four experiments were carried out from 1987 to 1989 in Granada, southern Spain. Two of these experiments used six potato cultivars with a single N rate, while the other two experiments used one cultivar and nine levels of N, split between planting and top-dressing. Variation in tuber yield between cultivars resulted mainly from differences in stem number per m² followed by tubers per stem and, to a lesser extent, average tuber weight. In N experiments, however, average tuber weight was the only yield component that showed a significant direct effect on yield, while the number of stems per m² and tubers per stem had negligible direct effects. In addition, the ontogenetic model used indicated compensatory mechanisms during the formation of the three yield components in the potato, which resulted stronger in the N experiments.  相似文献   

Effectiveness of amendments to restore metal-arsenic-polluted soil functions using Lactuca sativa L. bioassays     

Verónica González  Mariano Simón  Inés García  Juan Antonio Sánchez  Fernando del Moral 《Journal of Soils and Sediments》2013,13(7):1213-1222

Purpose

Because the success of the stabilisation of contaminants from amendments depends on the pollutants involved and the amendments used, the goals of this study were to assess whether selected amendments are able to restore highly polluted soils and to advance the knowledge of both the most suitable amendments to restore polluted soils and the most appropriate bioassays to estimate soil toxicity.

Materials and methods

An acidic and polluted soil from mining waste was amended with marble sludge, compost and iron in nine different combinations. The soils were placed in plastic pots and bioassays, including the different stages in the development of lettuce (Lactuca sativa L.), were carried out. Pore water was analysed at the different stages of the development of lettuce. At the end of the experiment, pollutant concentrations in lettuce leaf were analysed and the sequential extraction of trace elements was performed.

Results and discussion

The effectiveness of the amendments in reducing the toxicity of contaminated soils varied depending on the bioassay used. Marble sludge was the most effective in increasing pH and in reducing pollutant concentrations in pore water, clearly encouraging germination, root elongation and emergence. Throughout the emergence phase, marble sludge decreased in its effectiveness, probably because the pollutants precipitated as hydroxides and carbonates were taken up by the lettuce. In contrast, the compost began to improve the elongation of the seedling and the growth of lettuce. Although the amendments were effective in reducing the negative impact of pollutants in soils, none of them was able to successfully restore the functions of highly polluted soil.

Conclusions

The development of the plant until the end of the establishment phase is the best index to estimate soil phytotoxicity, although the effect on the health of potential consumers can only be evaluated from the toxic element concentrations in the plant. The uptake of pollutants stabilised by the amendments would explain why the reduction of easily available pollutant concentrations does not necessarily imply the restoration of the normal functioning of the ecosystem.  相似文献   

Phenotypic,molecular and pathogenic characterization of Phlyctema vagabunda,causal agent of olive leprosy          下载免费PDF全文

J. Romero  M. C. Raya  L. F. Roca  C. Agustí‐Brisach  J. Moral  A. Trapero 《Plant pathology》2018,67(2):277-294

Olive leprosy, caused by the fungus Phlyctema vagabunda, is a classic fruit rot disease widespread in the Mediterranean basin. From 2009 to 2013, new disease symptoms consisting of small circular necrotic leaf lesions, coin branch canker and shoot dieback were observed in Spanish and Portuguese olive orchards showing intense defoliation. Phlyctema‐like anamorphs were consistently isolated from leaves and shoots with symptoms. Representative isolates from affected leaves, shoots and fruits were characterized based on morphology of colonies and conidia, optimum growth temperature and comparison of DNA sequence data from four regions: ITS, tub2, MIT and rpb2. In addition, pathogenicity tests were performed on apple and olive fruits, and on branches and leaves of olive trees. Maximum mycelial growth rate ranged between 0.54 and 0.73 mm per day. Conidia produced on inoculated apple fruits showed slight differences in morphology among the representative fungal isolates evaluated. Phylogenetic analysis clustered all of the Phlyctema‐like isolates in the same clade, identifying them as Phlyctema vagabunda. On fruits, influence of wounding, ripening and cultivar resistance was studied, with cv. Blanqueta being the most susceptible cultivar. On branches, a mycelial‐plug inoculation method reproduced olive leprosy symptoms and caused shoot dieback. On leaves, Koch's postulates were fulfilled and the pathogen caused characteristic necrotic spots and plant defoliation. This is the first time that the pathogenicity of P. vagabunda in olive leaves has been demonstrated.  相似文献   

Mecanismos de Desarrollo de la Cúpula en los Conductos Semicirculares de las Aves: I. Secreción Celular     

O. Gonzalez  Sequeros  J. E. Guijarro de  Pablos  J. R. Moral  Rubio J. A. Ramirez  Gonzalez 《Anatomia, histologia, embryologia》1989,18(3):205-226

A study of the crista ampullaris of the vestibular apparatus was carried out in chicken embryos. The study group included embryos between stages 24 and 39 of Hamburger-Hamilton. This study elucidates the relationship of the cupula with respect to the epithelium of the crista ampullaris. With electron microscopic examination, the rough endoplasmic reticulum of the crista epithelial sustentacular cells at developmental stage of 31 H-H, demonstrated dilatations containing secretory material. Vesicles, with adhering ribosomes appear to be formed from these dilatations. At later stages of development, the vesicular material took on the characteristics of the fibrillary material composing the cupula. In some cells, secretory vesicles are seen near the apical border of these cells, where they apparently secrete vesicular contents into the endolymphatic space, contributing to the formation of the cupula.  相似文献   

Effects of an Early Application of Sulphur or Etephon as Foliar Spray on the Growth and Yield of Spring Barley in a Mediterranean Environment     

J. M. Ramos    L. F. Garcia del Moral  J. L. Molina-Cano  P. Salamanca  F. Roca de Togores 《Journal of Agronomy and Crop Science》1989,163(2):129-137

Leaf area development, biomass production and yield of four spring barley varieties grown in a Mediterranean environment (southern Spain) in response to an early application of foliar sulphur or etephon have been studied. Both sulphur and etephon produced similar results compared to the control. Thus, whereas the maximum leaf area index on untreated plots was reached at the beginning of shooting, the growth of foliar area in the treated ones was extended until anthesis and its decline during maturity was similarly retarded. This led to a significant improvement in the biomass at anthesis (which was closely correlated with grain yield) as well as in the leaf area duration during grain filling. These effects were principally due to variations in the number of leaves per plant, caused by a higher tiller production in the treated plants and not by an increase in the number of leaves per tiller or by leaf size.
An application of sulphur or etephon at tillering increases grain yield by raising both the number of ears per plant and per plot, without modifying the number of grains per ear or 1000-grain weight. The similarity between the effects of sulphur and etephon may be due to the fact that sulphur absorbed by the leaves results in an increase in methyonine, the biological precursor or ethylene. The positive correlation between biomass at anthesis and number of ears over grain yield suggests that sink capacity and source activity are closely related and both simultaneously limited by the environment.  相似文献   

Understanding the relationships between genetic and phenotypic structures of a collection of elite durum wheat accessions     

Conxita Royo  Marco Maccaferri  Fanny Álvaro  Marc Moragues  Maria Corinna Sanguineti  Roberto Tuberosa  Fouad Maalouf  Luis F. García del Moral  Andrea Demontis  Sayar Rhouma  Miloudi Nachit  Nasserlehaq Nserallah  Dolors Villegas 《Field Crops Research》2010

A collection of 191 durum wheat accessions representing Mediterranean Basin genetic diversity was grown in nine different environments in four countries, with productivities ranging from 0.99 to 6.78 t ha⁻¹. The population breeding structure comprised eight genetic subpopulations (GSPs) using data derived from 97 evenly distributed SSR markers. The phenotypic structure was assessed: (i) from the mean values of six agronomic traits across environments (multivariate), and (ii) from data representing each trait in each environment (univariate). Mean daily maximum temperature from emergence to heading was significantly (P < 0.05) and negatively associated to yield, accounting for 59% of yield variations. Significant but weak relationships were obtained between the genetic similarities among accessions and their overall agronomic performance (r = 0.15, P < 0.001), plant height (r = 0.12, P < 0.001), spike–peduncle length (r = 0.06, P < 0.01) and thousand kernel weight (r = 0.03, P < 0.05), suggesting a very low possibility of prediction of the agronomic performance based on random SSR markers. The percentage of variability (measured by sum of squares) explained by the environment varied between 76.3 and 98.5% depending on the trait, while that explained by genotypes ranged between 0.4 and 12.6%, and that explained by the GE interaction ranged from 1.1 to 12.5%. The clustering of the accessions based on multivariate phenotypic data offered the best explanation of genotypic differences, accounting for 30.3% (for yield) to 75.1% (for kernel weight) of the observed variation. The genotype × environment interaction was best explained by the phenotypic univariate clustering procedure, which explained from 28.5% (for kernel weight) to 74.9% (for days to heading) of variation. The only accessions that clustered both in the genetic dissimilarities tree and the tree obtained using Euclidean distances based on standardized phenotypic data across environments were those closely related to the CIMMYT hallmark founder ‘Altar 84’, the ICARDA accessions adapted to continental-dryland areas, and the landraces, suggesting that genetic proximity corresponded to agronomic performance in only a few cases.  相似文献   

Effect of solid waste compost on microbiological and physical properties of a burnt forest soil in field experiments   总被引：2，自引：0，他引：2  

C. Guerrero  I. Gómez  J. Mataix Solera  R. Moral  J. Mataix Beneyto  M. T. Hernández 《Biology and Fertility of Soils》2000,32(5):410-414

 The restoration of soil microbial activities is a basic step in the reclamation of burnt soils. For this reason, the ability of municipal solid waste compost to accelerate the re-establishment of bacterial and fungal populations, as well as to re-establish physical properties in a burnt soil, was evaluated in a field experiment. Four treatments were performed by adding different doses of compost (0, 0.5, 1 and 2 kg compost m^–2 soil) to a burnt Calcic Rodoxeralf soil, and the changes in microbial populations, salt content, aggregate stability and bulk density were evaluated for 1 year. Initially, the addition of compost had a negative effect on soil microbial populations, but 3 months after compost addition, the number of viable fungal propagules increased in all the amended soils. This positive effect lasted until the end of the experiment. From 30 days onwards, all the amended soils showed a greater total number of bacterial cell forming units than the unamended burnt soil. Organic amendment increased the percentage of 2- to 4-mm aggregates, although the effect on the stability of the 0.2- to 2-mm aggregates and on bulk density was less noticeable. Received: 24 November 1999  相似文献   

Alkalization and Cationization of Cellulose: Effects on intrinsic viscosity     

Ana Moral  Roberto Aguado  Antonio Tijero 《Fibers and Polymers》2016,17(6):857-861

Researchers have studied the cationization of polysaccharides to replace conventional cationic polyelectrolytes, linked to environmental issues. However, cationic celluloses have not achieved the success of cationic starches. The knowledge of the cellulose cationization proccess needs to be improved. In this work, we pretreat (alkalize) and cationize cotton linters and α-cellulose powder, using 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in an aqueous-alcoholic alkaline solution. The pretreatment took place under different conditions, whereas the cationization itself was always performed at 70 ºC, for a CHPTAC/AGU (anhydro glucose units) mole ratio of 4, and for a total time of 5 h for cotton linters or 100 min for α-cellulose powder. The degree of substitution, the crystallinity index and the temporal evolution of intrinsic viscosity are provided for the 18 experiments performed. The background was uncertain about the effect of cationization on intrinsic viscosity. Here, we report increasing viscosity with increasing degree of substitution and cationization time. Furthermore, intrinsic viscosity increased with increasing cationization time, even when the degree of substitution had leveled off. Seemingly, the incorporation of positive charges into cellulose changed the polymer distribution and the interactions between the polymer and the solvent.  相似文献   

The effect of synthetic pesticides and sulfur used in conventional and organically grown strawberry and soybean on Neozygites floridana,a natural enemy of spider mites          下载免费PDF全文

Thiago Castro  Samuel Roggia  Vitalis W Wekesa  Rafael de Andrade Moral  Clarice GB Demétrio  Italo Delalibera Jr  Ingeborg Klingen 《Pest management science》2016,72(9):1752-1757

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