Search results for "classification"
showing 10 items of 29475 documents
Phylogeny, biogeography, and morphological ancestral character reconstruction in the Mediterranean genus Fumana (Cistaceae)
2020
Fumana is a diverse genus of the Cistaceae family, consisting of 21 currently accepted species. In this study, nuclear (ITS) and plastid (matK, trnT‐L) molecular markers were used to reconstruct the phylogeny and to estimate divergence times, including 19 species of Fumana. Phylogenetic analyses (Bayesian Inference, Maximum Parsimony and Maximum Likelihood) confirmed the monophyly of Fumana and did not support the infrageneric divisions previously established. The results support four main clades that group species that differ in vegetative and reproductive characters. Given the impossibility to define morphological characters common to all species within the clades, our proposal is to reje…
Morphological observations on the reproductive structures of Ambrosina (Araceae), a Mediterranean endemic monotypic genus
2017
This research was carried out to better define the pollen, fruit and seed morphology of Ambrosina bassii , the only species of this rare Mediterranean endemic genus. Pollen traits were already known, but here we investigated on their variability in distant populations and in different morphotypes (‘varieties’). Fruit and seed traits were almost unknown, also because of the rarity of fruit-set in this species. The surface features of pollen, fruit and seed, as well as length, width and length/width ratio, were analysed by means of scanning electron microscopy (SEM). Comparative observations were made also on Arisarum vulgare , since Arisarum is the closest genus. The principal component anal…
Phenotypic variation across populations of red mullet (Mullus barbatus) in different environments of the central Mediterranean
2020
Geometric morphometrics is an effective tool for quantifying intraspecific variations in fish body shape and differentiating populations and fisheries stocks. This study used geometric morphometrics to examine patterns of intraspecific morphological differentiation among four red mullet (Mullus barbatus) populations in the Strait of Sicily in the central Mediterranean Sea. We hypothesised that morphological differences among local populations were caused by the diverse hydrodynamic features characterising the sampled areas and maintained by geographical isolation. We also examined whether body shape homogeneity or variability within local populations was related to seabed rugosity as an in…
Exploring connectivity between spawning and nursery areas ofMullus barbatus(L., 1758) in the Mediterranean through a dispersal model
2017
Connectivity between spawning and nursery areas plays a major role in determining the spatial structure of fish populations and the boundaries of stock units. Here, the potential effects of surface current on a red mullet population in the Central Mediterranean were simulated using a physical oceanographic model. Red mullet larvae were represented as Lagrangian drifters released in known spawning areas of the Strait of Sicily (SoS), which represents one of the most productive demersal fishing-grounds of the Mediterranean. To consider the effect of inter-annual variability of oceanographic patterns, numerical simulations were performed for the spawning seasons from 1999 to 2012. The main goa…
Nanism (dwarfism) in fish: a comparison between red mullet Mullus barbatus from the southeastern and the central Mediterranean
2007
The gradient of environmental conditions from west to east in the Mediterranean results in very low primary productivity in the eastern area of this sea. This impoverishment is expressed also in higher trophic levels and has been accounted for by several faunistic phenomena. One of these is 'Levantine nanism' (dwarfism); this is characterized by smaller body size of specimens in the Levantine basin compared with conspecifics in the western Mediterranean. Nanism has been hypothesized for various taxonomic groups in the Mediterranean, but no quantitative study has yet been carried out to confirm it. In the present study male and female red mullet Mullus barbatus from trawl surveys carried out…
Testing the potential significance of different scion/rootstock genotype combinations on the ecology of old cultivated olive trees in the southeast M…
2017
Background A previous multi-locus lineage (MLL) analysis of SSR-microsatellite data of old olive trees in the southeast Mediterranean area had shown the predominance of the Souri cultivar (MLL1) among grafted trees. The MLL analysis had also identified an MLL (MLL7) that was more common among rootstocks than other MLLs. We here present a comparison of the MLL combinations MLL1 (scion)/MLL7 (rootstock) and MLL1/MLL1 in order to investigate the possible influence of rootstock on scion phenotype. Results A linear regression analysis demonstrated that the abundance of MLL1/MLL7 trees decreases and of MLL1/MLL1 trees increases along a gradient of increasing aridity. Hypothesizing that grafting o…
ENVIRONMENTAL FACTORS IMPACT AND INCIDENCE OF PARASITISM OF PSYLLAEPHAGUS BLITEUS RIEK (HYMENOPTERA ENCYRTIDAE) ON POPULATIONS OF GLYCASPIS BRIMBLECO…
2018
The red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera, Aphalaridae), is an Australian native sap-sucking insect pest of eucalypts that has been first reported for the West Palaearctic Region in 2008 and, in 2010, it has been found also in Italy. Subsequently its primary parasitoid, Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae), was also detected within the main European and North African infested areas, where no release of the parasitoid was ever performed. This study, carried out in 30 Eucalyptus camaldulensis plantations located along the coast, on the hills and the mountains in Mediterranean climatic areas of Sicily (Italy), aimed to determine the influence of environ…
Carbon storage of Mediterranean grasslands
2016
Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses (Ampelodesmos mauritanicus and Hyparrhenia hirta) and an invasive alien grass (Pennisetum setaceum). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands,…
Inter- and intra-variability of seed germination traits of Carpobrotus edulis N.E.Br. and its hybrid C. affine acinaciformis.
2018
Invasions by alien Carpobrotus spp. have been recognised as one of the most severe threats to Mediterranean climate coastal ecosystems, and Carpobrotus is considered one of the most widespread invasive alien genera in the Mediterranean Basin. The aims of this study were to characterise seed germination of both C. edulis and its hybrid C. aff. acinaciformis, in terms of photoperiod, temperature and salinity. Inter- and intra-specific variability in the responses to photoperiod (12/12 h light and total darkness), constant temperatures (5, 10, 15, 20, 25 °C) and an alternating temperature regime (25/10 °C), salt stress (0, 125, 250, 500 mm NaCl) and the recovery of seed germination were evalua…
Allium nazarenum (Amaryllidaceae), a new species of the section Codonoprasum from Israel
2017
Allium nazarenum, a new species of A. sect. Codonoprasum, is described and illustrated from Israel. Within this species, two well distinct subspecies have been recognized, represented by the subsp. nazarenum and subsp. ramonense respectively. The first one occurs in northern and central Israel, which falls within the Mediterranean bioclimate, while the second one is circumscribed to the Negev desert. Both taxa are diploid with 2n = 16 and are found on various substrata usually in the batha or steppic plant communities. This species shows close relationships with the species belonging to the A. staticiforme group, from which it differs in several relevant diacritic features. Its morphology, …