Investigation of different apple cultivars by high resolution magic angle spinning NMR. A feasibility study

(1)H HR-MAS NMR spectroscopy was applied to apple tissue samples deriving from 3 different cultivars. The NMR data were statistically evaluated by analysis of variance (ANOVA), principal component analysis (PCA), and partial least-squares-discriminant analysis (PLS-DA). The intra-apple variability of the compounds was found to be significantly lower than the inter-apple variability within one cultivar. A clear separation of the three different apple cultivars could be obtained by multivariate analysis. Direct comparison of the NMR spectra obtained from apple tissue (with HR-MAS) and juice (with liquid-state HR NMR) showed distinct differences in some metabolites, which are probably due to changes induced by juice preparation. This preliminary study demonstrates the feasibility of (1)H HR-MAS NMR in combination with multivariate analysis as a tool for future chemometric studies applied to intact fruit tissues, e.g. for investigating compositional changes due to physiological disorders, specific growth or storage conditions.     

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.     

A novel type of seaweed extract as a natural alternative to the use of iron chelates in strawberry production

The new generation of seaweed extracts, such as Actiwave^®, may represent a promising strategy to reduce the use of phytochemicals in agriculture. Actiwave^® is a metabolic enhancer derived by the algae Ascophillum nodosum, but differently from some older seaweed extracts, it has a constant and balanced formulation containing kahydrin, alginic acid and betaines which synergistically contribute to the efficacy of the product. Actiwave^® has been proposed to increase the mineral nutrient uptake and the abiotic stress tolerance. The aim of this work was to evaluate, under a multidisciplinary approach, the effect of the biostimulant on the vegetative and productive performances of strawberry plants grown on a lime inducing iron chlorosis substrate. This biostimulant increased the vegetative growth (10%), the leaf chlorophyll content (11%), the stomata density (6.5%), the photosynthetic rate and the fruit production (27%) and berry weight. The most significant result was the increase of the plant biomass: the shoot dry matter was increased up to 27% and root dry matter up to 76%. Finally, preliminary experiments showed that Actiwave^® positively influenced also the root-associated microbial biocoenosis. These results are discussed in relation to the physiological and ecological mechanisms proposed to explain the beneficial effects of this seaweed extract. Finally, the effects of Actiwave^® and sequestrene were significantly similar, thus showing that this biostimulant may represent an environmental-friendly substitute of the iron chelates.