Summary 1.Several recent studies have considered the relative effects of local vs. landscape factors on diversity of several animal taxa in grasslands. However, very few have considered vascular plant or Orthoptera species, both of which are important biotic components of grassland ecosystems. The general aim of this study was to determine the effect of grassland management and landscape composition, and their potential interactions, on diversity patterns of vascular plants and Orthoptera in Alpine hay meadows. 2. We considered three groups of management regimes defined by different amounts of fertilizer nitrogen applied and cutting frequency: (i) extensive, (ii) low intensive and (iii) intensive meadows situated in different landscape contexts. To evaluate the relative importance of meadow management and landscape composition on diversity patterns, we applied analysis of covariance and variation partitioning analyses. 3. Diversity patterns of both taxonomic groups were affected primarily by grassland management. The extensive management regime was most suitable for conserving high species richness of both taxonomic groups. The intensive meadows were characterized by plant communities dominated by a few ruderal and competitor species, and by Orthoptera communities composed of only a few abundant Caelifera species (e.g. Chorthippus parallelus ), while Ensifera species had very low individual densities. 4. Regarding the landscape determinants, plant diversity patterns were not significantly related to any landscape composition variables. In contrast, a high proportion of urban elements and grassland in the surrounding landscape (radius 500 m) affected Orthoptera species richness negatively. 5. Synthesis and applications . The implementation of well-targeted agri-environment schemes for compensation payments against intensification and abandonment of extensive hay meadows seems to be a promising tool to protect both taxonomic groups. In this context, we suggest that the existing Swiss ecological compensation area (ECA) hay meadow agri-environment scheme, which requires at least one cut every year and no fertilizer application, might also be suitable for the Italian Alps. Moreover, the significant influence of landscape composition on Orthoptera diversity suggests that the effectiveness of measures applied at a field scale may be improved by integration of protected area schemes, promoting extensive management at a farm scale.

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Modern rural policies that incorporate agricultural and environmental aims within the broader framework of sustainable rural development are being formulated to address the problem of declines in grassland biodiversity and the destruction of sensitive landscapes and habitats in Europe. Extensification is the process of reducing fertiliser inputs, management intensity and stocking rates, and is central to these sustainable rural policies. However, research in the Less Favoured Areas of Europe has been fragmented and highly variable reflecting the different uses and requirements of our upland areas. Information is needed to determine the nature and timescale of changes in such systems, and whether extensive management is sustainable in the long-term. This paper presents results from a range of grassland extensification experiments across Europe, mainly within the European Union, over the past 30 years that quantify the impacts on soil, plant and animal components of the system. All have the common theme of changing the focus of land management from solely the agricultural product to include a broader range of ecological and environmental objectives. Beneficial changes in biodiversity resulted from more extensive management treatments, but at the cost of reductions in total animal output, and in some cases a reduction in individual animal performance. However, it is clear that it is a long-term process to achieve many of these changes in biodiversity, and this must be recognised by policy makers. We recommend that future extensification studies adopt an approach that will allow their results to be applied throughout Europe.

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BackgroundFusarium oxysporum f. sp. melonis Snyd. & Hans. (FOM) causes Fusarium wilt, the most important infectious disease of melon (Cucumis melo L.). The four known races of this pathogen can be distinguished only by infection on appropriate cultivars. No molecular tools are available that can discriminate among the races, and the molecular basis of compatibility and disease progression are poorly understood. Resistance to races 1 and 2 is controlled by a single dominant gene, whereas only partial polygenic resistance to race 1,2 has been described. We carried out a large-scale cDNA-AFLP analysis to identify host genes potentially related to resistance and susceptibility as well as fungal genes associated with the infection process. At the same time, a systematic reisolation procedure on infected stems allowed us to monitor fungal colonization in compatible and incompatible host-pathogen combinations.ResultsMelon plants (cv. Charentais Fom-2), which are susceptible to race 1,2 and resistant to race 1, were artificially infected with a race 1 strain of FOM or one of two race 1,2 w strains. Host colonization of stems was assessed at 1, 2, 4, 8, 14, 16, 18 and 21 days post inoculation (dpi), and the fungus was reisolated from infected plants. Markedly different colonization patterns were observed in compatible and incompatible host-pathogen combinations. Five time points from the symptomless early stage (2 dpi) to obvious wilting symptoms (21 dpi) were considered for cDNA-AFLP analysis. After successful sequencing of 627 transcript-derived fragments (TDFs) differentially expressed in infected plants, homology searching retrieved 305 melon transcripts, 195 FOM transcripts expressed in planta and 127 orphan TDFs. RNA samples from FOM colonies of the three strains grown in vitro were also included in the analysis to facilitate the detection of in planta-specific transcripts and to identify TDFs differentially expressed among races/strains.ConclusionOur data suggest that resistance against FOM in melon involves only limited transcriptional changes, and that wilting symptoms could derive, at least partially, from an active plant response.We discuss the pathogen-derived transcripts expressed in planta during the infection process and potentially related to virulence functions, as well as transcripts that are differentially expressed between the two FOM races grown in vitro. These transcripts provide candidate sequences that can be further tested for their ability to distinguish between races.Sequence data from this article have been deposited in GenBank, Accession Numbers: HO867279-HO867981.

A reliable and species-specific real-time quantitative polymerase chain reaction (qPCR) assay was developed for detection of the complex soilborne anamorphic fungus Fusarium oxysporum. The new primer pair, designed on the translation elongation factor 1-α gene with an amplicon of 142 bp, was highly specific to F. oxysporum without cross reactions with other Fusarium spp. The protocol was applied to grafted melon plants for the detection and quantification of F. oxysporum f. sp. melonis, a devastating pathogen of this cucurbit. Grafting technologies are widely used in melon to confer resistance against new virulent races of F. oxysporum f. sp. melonis, while maintaining the properties of valuable commercial varieties. However, the effects on the vascular pathogen colonization have not been fully investigated. Analyses were performed on 'Charentais-T' (susceptible) and 'Nad-1' (resistant) melon cultivars, both used either as rootstock and scion, and inoculated with F. oxysporum f. sp. melonis race 1 and race 1,2. Pathogen development was compared using qPCR and isolations from stem tissues. Early asymptomatic melon infections were detected with a quantification limit of 1 pg of fungal DNA. The qPCR protocol clearly showed that fungal development was highly affected by host-pathogen interaction (compatible or incompatible) and time (days postinoculation). The principal significant effect (P ≤ 0.01) on fungal development was due to the melon genotype used as rootstock, and this effect had a significant interaction with time and F. oxysporum f. sp. melonis race. In particular, the amount of race 1,2 DNA was significantly higher compared with that estimated for race 1 in the incompatible interaction at 18 days postinoculation. The two fungal races were always present in both the rootstock and scion of grafted plants in either the compatible or incompatible interaction.

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