Search results for "VARIATION"
showing 10 items of 2124 documents
Pheno-morphological, agronomic and genetic diversity among natural populations of sulla (Hedysarum coronarium L.) collected in Sicily, Italy
2010
Sulla (Hedysarum coronarium L.) is a short-lived perennial forage legume that plays a key role in cereal-based systems in semi-arid Mediterranean regions, particularly in organic production and low-input oriented agriculture. In Sicily, the species is widespread both as a wild and cultivated plant. The present study assessed the phenotypic and genetic variation among natural populations of sulla collected from different environments throughout Sicily and analysed how the patterns of phenotypic diversity varied according to the environmental parameters of each collection site. Two commercial varieties and two Sicilian agro-ecotypes were also included in the study as controls. Principal compo…
Population structure in the Méditerranean basin: a Y chromosome perspective
2006
The Mediterranean region has been characterised by a number of pre-historical and historical demographic events whose legacy on the current genetic landscape is still a matter of debate. In order to investigate the degree of population structure across the Mediterranean, we have investigated Y chromosome variation in a large dataset of Mediterranean populations, 11 of which are first described here. Our analyses identify four main clusters in the Mediterranean that can be labelled as North Africa, Arab, Central-East and West Mediterranean. In particular, Near Eastern samples tend to separate according to the presence of Arab Y chromosome lineages, suggesting that the Arab expansion played a…
Genetic architecture of the marbled goby Pomatoschistus marmoratus (Perciformes, Gobiidae) in the Mediterranean Sea
2011
The marbled goby Pomatoschistus marmoratus, a species inhabiting coastal Mediterranean lagoons, has been studied by measuring its mitochondrial DNA variation. This analysis revealed a Mediterranean west vs east split and, subsequently, an eastern differentiation among the Libyan–Tunisian Gulf, the Adriatic Sea and the Aegean Sea. The high cohesion between the samples collected in the vast area of western Mediterranean contrasts with the genetic mosaic of the more sub-structured eastern Mediterranean. This western homogeneity can not yet be fully explained even if a human-mediated migratory flow, due to a maritime traffic, has been posited. The pattern in the eastern basin revealed a genetic…
Allozyme Similarity in Two Morphologically Distinguishable Populations ofParacentrotus Lividus(Echinodermata) From Distinct Areas of the Mediterranea…
1998
Allozymes ofParacentrotus lividusfrom Palermo Gulf in the northern Sicilian coast (Italy) and from a small body-size population in the western Greek coast (Ionian Sea) were investigated by PAGE. Five of the twenty examined loci were polymorphic(AAT*, ADH*, ME*, PGI*andPGM*)over each population with a polymorphism value of 0–25. Average heterozygosity was equal to 0081 in the Sicilian sample and 0084 in the Greek. Deviations from Hardy-Weinberg equilibrium were significant inME*andPGI*loci (as calculated byy).Nei's (1978) genetic distance (D=0–0025) index described a close identity between the two samples. FSTvalue of polymorphic loci ranged from 0001 to 0029, its mean value (0–008) resultin…
A Common Genetic Origin for Early Farmers from Mediterranean Cardial and Central European LBK Cultures
2015
Olalde, Iñigo et al.
Spatial relations of heavy metals in arable and greenhouse soils of a Mediterranean environment region (Spain)
2013
This study characterises and compares Cr, Ni, Pb, Cu, Zn and Cd (HMs) contents and the main edaphic parameters in arable soils (AS) from western areas of the Andalusian Autonomous Community (SE Spain) with greenhouse soils (GS) from the province of Almería, one of the most productive agricultural systems in Europe. We explored 199 GS and 142 AS, representing local and regional scales of variation in this important Mediterranean area. The hazardousness of HMs was particularly relevant in GS where agricultural practices, which centre on maximising production, end up with products that finally enter the human food chain directly. Despite their similar edaphic characteristics, the main differen…
On the origin of European sheep as revealed by the diversity of the Balkan breeds and by optimizing population-genetic analysis tools
2020
Background In the Neolithic, domestic sheep migrated into Europe and subsequently spread in westerly and northwesterly directions. Reconstruction of these migrations and subsequent genetic events requires a more detailed characterization of the current phylogeographic differentiation. Results We collected 50 K single nucleotide polymorphism (SNP) profiles of Balkan sheep that are currently found near the major Neolithic point of entry into Europe, and combined these data with published genotypes from southwest-Asian, Mediterranean, central-European and north-European sheep and from Asian and European mouflons. We detected clines, ancestral components and admixture by using variants of commo…
Insular variation in central MediterraneanCrociduraWagler, 1832 (Mammalia, Soricidae)
1990
Morphometric variation of Crocidura mandible in Sicily and surrounding islands (Egadi archipelago, Ustica, Pantelleria and Gozo) was analyzed by principal component and canonical variate analyses in order to integrate recent chromosomal and biochemical observations. Specimens of C. suaveolens and C. leucodon from mainland Italy and of C. russula from Sardinia were used as reference in this analysis. The biometry of the only taxon of shrews living in Sicily is significantly different from the three reference samples. This result, coupled with a recently discovered new karyotype, provides strong evidence for a new Eurasian species, for which the name C. sicula Miller 1901, was chosen. Crocidu…
HAPEX-Sahel
1997
The variation in evaporative fraction and actual evaporation is examined for three sample days in the HAPEX-Sahel Intensive Observation Period (IOP), including data from all the vegetation types and sites. The trends in evaporative fraction over the IOP are also presented for eight sites. The high rate of evaporation from bare soil in the days following rainfall produces a variability in evaporation which makes differences between sites difficult to interpret on a day-to-day basis, but over the whole IOP it is shown that the millet uses a smaller proportion of the available energy for evaporation than the tiger bush or fallow savannah. The combined effect of differences in the total energy …
CONCENTRATION MEASUREMENTS OF 7Be AT GROUND LEVEL AIR AT PALERMO, ITALY- COMPARISON WITH SOLAR ACTIVITY OVER A PERIOD OF 21 YEARS
2003
Air activity concentrations of (7)Be in Palermo determined for the period January 1995-December 2002 by gamma-ray spectrometric analysis of particulate samples collected on paper filter by a high-volume sampler (approximately 900 m(3) h(-1)) are reported. The temporal behaviour of (7)Be concentration presents the same characteristics already observed in the measurements carried out over the previous 13-year (1982-1994) investigated period. The mean value of 5.06 mBq m(-3) obtained from the analysis of the 4636 particulate samples collected from 1982 to 2002 can be considered a representative value of (7)Be air concentration at ground level in our geographical zone. The comparison of long-te…