Genotypic and bio-agronomical characterization of an early Sicilian landrace of globe artichoke

In Sicily, the increasing use of exotic globe artichoke germplasm is eroding the presence of autochthonous landraces, including the long established ‘Violetto di Sicilia’. Ten clones have emerged from a clonal selection programme in this landrace, and here we describe the variation that they capture both at the level of AFLP-based genotype and phenotypically with respect to key productivity traits, on the basis of two seasons of field evaluation. The clonal selections yielded, on average, 8.9 heads per plant (equivalent to a fresh weight yield of 1.28 kg). Two clones yielded particularly well in both growing seasons (10.6 heads, equivalent to 1.46 kg per plant), while another pair produced particularly large heads (on average 165 g) and a high receptacle incidence (on average 19.3 g 100 g⁻¹ fresh weight). Both the number of days to first harvest and the quantity of head dry matter were subject to a significant degree of ‘clone × year’ interaction. Yield, the number of heads per plant and receptacle incidence were associated with a moderate (0.30–0.53) broad sense heritability, indicating that these traits could be successfully improved by phenotype-based clonal selection. AFLP fingerprinting was able to discriminate between all the clones, based on only three primer combinations. A principal component analysis based on the AFLP fingerprints was used to compare the selected clones with a set of individuals chosen on the basis of maximum genetic diversity. This comparison suggested that the new clone set was representative of the genetic variation present in ‘Violetto di Sicilia’, because the diversity captured by the two sets was largely overlapping, confirming the possibility of carrying out clonal selection in this globe artichoke landrace without compromising its preservation in situ.     

In vitro down regulation of proinflammatory cytokines induced by LPS tolerance in pig CD14+ cells

LPS tolerance is characterized by a reduced sensitivity to subsequent challenge of LPS. In human and mouse models LPS tolerance is closely associated with marked unbalanced production of leukocyte-derived inflammatory mediators which, when overexpressed, led to septic syndrome and shock. Here we characterized the in vitro induction of LPS tolerance in porcine CD14+ spleen cells in order to give insights into LPS tolerance in pigs. Following LPS stimulation, TNF-alpha and, to a minor extent, IL-8 production showed a significant reduction in CD14+ spleen monocytes that were pretreated with LPS in comparison to na?ve cells, while IL-1beta production was slightly influenced by LPS stimulation and it was not affected by subsequent LPS challenge. Our findings showed that porcine CD14+ cells undergo a process, which resembles LPS tolerance, providing evidence that swine represent a valuable and useful model to perform experiments to study LPS tolerance and its biological significance.     

Recombinant bovine interleukin-12 stimulates a gut immune response but does not provide resistance to Cryptosporidium parvum infection in neonatal calves

This study was undertaken to determine if administration of recombinant bovine interleukin-12 (rBoIL-12) could stimulate a cellular immune response that protected calves from an oral challenge inoculation with Cryptosporidium parvum oocysts. In a first experiment, rBoIL-12 intraperitoneally administered as a single dose 1 day before challenge inoculation, did not alter the course of infection. The percentage of immune competent cells and levels of cytokine gene expression in the ileo-cecal mucosa and in the draining lymph nodes of treated calves were similar to those of untreated control calves. However, when rBoIL-12 was subcutaneously administered daily from 2 days before infection to 2 days after infection, a consistent increase of T lymphocytes and an higher expression of interferon-gamma (IFN-gamma) was detected. Again, treatment did not alter the course of infection. Similar results were obtained when rBoIL-12 was administered daily for 4 days beginning 2 days after oral inoculation. These data indicate that although rBoIL-12 stimulated a strong immune response in the gut of neonatal calves, the response was not able to provide protection from challenge inoculation with C. parvum oocysts.     

Investigating the effects of afforestation on soil erosion and sediment mobilisation in two small catchments in Southern Italy

Annual soil losses in southern Italy can exceed 100–150 t ha^− 1 year^− 1. Where erosion on agricultural land is particularly severe, land use change and afforestation are frequently seen as the most appropriate means of reducing erosion risk. However, the overall effectiveness of afforestation in reducing soil erosion remains uncertain, due to the poor development of the forest cover in some areas, leading to significant areas with sparse tree cover, and the erosional impact of forest harvesting, which commonly involves clearcutting. The study reported here addresses this uncertainty and focuses on two small catchments (W2 and W3) located in Calabria, southern Italy, for which measurements of suspended sediment yield are available. Both the catchments originally supported a rangeland vegetation cover and they were planted with eucalyptus trees in 1968. Currently, only catchment W3 supports a continuous forest cover. In catchment W2 the forest cover is discontinuous and there is a significant area of the catchment (ca. 20%) where the tree cover is sparse and the vegetation cover is dominated by natural grasses. Two additional erosion plots were established within catchment W2 in 1991, in order to explore the effect of the density of the tree cover on soil erosion. Information on the sediment yields from the two catchments and the plots for 10 storm events that occurred during the period December 2005–December 2006 and associated information on the ¹³⁷Cs and excess ²¹⁰Pb of the sediment, have been used to investigate the effectiveness of afforestation in reducing sediment mobilisation and net soil loss from the catchments involved. The results demonstrate that the areas of greatest soil loss are associated with the slopes where the tree cover is discontinuous, and that forest harvesting by clearcutting causes significant short-term increases in sediment mobilisation and sediment yield. These findings, which are consistent with previous work undertaken within the same area, emphasize the importance of vegetation cover density in influencing rates of soil loss in the study catchments. The study also provided a useful demonstration of the potential for using measurements of the ¹³⁷Cs and ²¹⁰Pb_ex content of sediment, in combination with more traditional sediment monitoring, to investigate sediment sources and to compare the sediment dynamics of catchments subjected to different land management practices.     

GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

Species conservation largely depends on knowledge of habitat needs of target species. GIS-models are increasingly used to assess habitat preferences and distribution of target species, but their accuracy is constrained by availability of digital data layers. We developed a two-steps approach aiming at showing pros and cons of landscape (GIS)- and site-level habitat models, identifying key habitat factors for conservation of a threatened bird species, the red-backed shrike Lanius collurio. A spatially explicit GIS-model was generated using landscape variables, and a second model at site level was developed using fine-scale variables measured on the ground. The GIS-based model was then extrapolated to the entire region to obtain a map of distribution of suitable habitats. Positive associations between shrike occurrence and both hedgerow length and partial shrub cover were detected at both scales. Shrikes were also positively associated with grassland cover at landscape level and with partial cover of untilled herbaceous vegetation at the finer scale, and negatively affected by lucerne cover. The GIS-model led to an affordable map of predicted habitat suitability which should help conservationists to focus on different local priorities, but was unable to identify effects of untilled and lucerne cover. Site-level model gave fine details for habitat management, but its application elsewhere requires ground-measurements of factors. Combining the multiscale models could indicate more urgent actions at large scales (e.g. maintaining suitable habitats, or improving connectivity among isolated patches) and draw a detailed figure of the most suitable habitat for the species. Shrike occurrence was associated with a higher number of shrub and tree species: the indicator value of the species should ensure general benefits for biodiversity from dedicated management.