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La tutela e la gestione del suolo richiedono grande attenzione, viste le importanti funzioni ambientali, economiche, sociali e culturali che il suolo stesso svolge. I nematodi del suolo possono costituire degli utili bioindicatori dello stato di salute di un suolo, in quanto sono in grado di rispondere prontamente ai cambiamenti ambientali (stress e inquinamento) e pertanto l"analisi della loro distribuzione e attività può essere usata per stabilire lo stato di conservazione di un suolo. Il biomonitoraggio della nematofauna può essere condotto utilizzando diversi indici ecologici strettamente correlati all"arricchimento di materia organica ed ai gruppi trofici dei nematodi presenti nel terreno (Maturity Index e Enrichment Index). Nel corso del presente studio sono stati campionati tre diversi siti della regione Puglia, localizzati uno in una riserva naturale, il secondo in prossimità di una centrale elettrica a carbone e il terzo in prossimità di una discarica, e per ciascuno di essi è stata condotta l"analisi della nematofauna presente utilizzando sia approcci morfologici che molecolari. Il DNA totale della nematofauna presente in ciascun campione è stato estratto e sottoposto ad amplificazione mediante PCR. Il gene per il 18S rRNA è stato utilizzato come marcatore molecolare in quanto in banca dati esistono molte sequenze del 18S, tali da coprire l"intero phylum dei nematodi. Sono state determinate circa 100 sequenze per ciascun sito. L"analisi delle sequenze mediante BLAST ha permesso di classificare le sequenze ottenute a livello di genere, alcune delle quali sono state identificate anche a livello di specie. Gli indici ecologici sono stati calcolati sia per i dati morfologici che per i dati molecolari rivelando che i risultati dei due approcci sono sovrapponibili. I siti analizzati si sono rivelati più disturbati in corrispondenza della centrale elettrica e della discarica rispetto al sito nella riserva naturale. Questi risultati preliminari dimostrano che i nematodi sono sicuramente dei buoni indicatori dello stato di conservazione di un suolo.

The wide range of feeding types and the ability to adapt to seasonal succession make nematodes significant indicators of ecological conditions of the soil in which they occur. Soil nematophauna is highly sensitive to any environmental damage and, therefore, the analysis of soil nematode community can be a useful diagnostic tool of soil health changes caused by polluting agents, among which also pesticides. Traditional morpho-taxonomic techniques for analysis of soil nematophauna have been flanked or substituted by more innovative and quicker molecular tools. Effectiveness of morpho-taxonomic and molecular techniques was comparatively evaluated through the analysis of soil nematode community from three selected relatively undisturbed and disturbed sites in Apulia region (Italy). Nematodes for both analyses were extracted from 100g sub-samples of composite soil samples collected at each site. Specimens for morphological analysis were fixed in a 2.5% formaldehyde solution and then identified at family and genus level under an optical microscope. The maturity and trophic diversity indices were determined. Total DNA was extracted from the nematode community of each soil subsample and PCR amplification was performed by using the small subunit (18s) of the ribosomal DNA gene, as diagnostic marker. The 18s rDNA was selected because of the large number of 18s sequences in GenBank, the existence of an 18s-based phylogenetic tree and the conserved nature of this gene to ensure complete phylogenetic coverage of the phylum. Sequence analysis through BLAST allowed to classify most of them at genus level and some of them at species level. Few sequences showed no similarity with those present in the database suggesting that they are new for the scientific community. The maturityand trophic diversity indices were also calculated for genera identified at molecular level. Results confirmed that nematodes are good indicators of soil health, as showing a different level of disturbance for each of the three sampled sites. Both morpho-taxonomic and molecular tecniques showed to be effective, though morpho-taxonomic is more time-consuming and skilfulness-requiring whereas a molecular analysis is largely more expensive.

Soil nematodes are organisms that quickly respond to changes (stress and pollutants) in the environment and can be useful ecological indicators of environmental disruption. Since they occur in any environment containing organic carbon, they do not quickly escape from stressful conditions, occupy key positions in soil food webs and can be classified in easily identifiable trophic groups (Bongers and Ferris, 1999). While there are many indices of biological diversity, specific tools have been developed for nematodes, such as the Maturity Index (MI) and the 3 Enrichment lndex (El). These indices are based on an ecological classification where to each taxonomic family is assigned an ecological value that ranges from l (typical families of polluted soils or sediments) to 5 (typical families of soils or sediments). The lower values (1 and 2) belong to colonizer nematodes (c), i.e. opportunists, characterized by a rapid biological cycle and able to quickly invade unstable or polluted habitats. High values (3 to 5) belong to persister nematodes (p), characterized by a slow reproduction rate. Persisters are more sensitive to pollutants and 1 other disturbances than colonizers, therefore MI also serve to measure the impact of mixtures of pollutants and the effect of their complex interactions with biotic and abiotic environment. The aim of this study was to identify the nematofauna, recovered from three different habitats, at morphological and molecular level to provide useful information on the soil features and any possible disturbances by calculating ecological indexes of soil biodiversity

Nematodes are widely recognised as bioindicators of the soil environment health. Analysis of soil nematode community is increasingly used to calculate various ecological indices related to enrichment and trophic status of nematofauna. The soil nematode community from three selected relatively undisturbed and disturbed sites in the Apulia region (Italy) was comparatively studied through both morpho-taxonomic and molecular analysis. Nematodes for both analyses were extracted from 100 g sub-samples from composite soil samples collected at each site. Nematodes were fixed in a 2.5% formaldehyde solution and then identified at family and genus level under an optical microscope. The maturity and trophic diversity indices were determined. For the molecular study, total DNA was extracted from the nematode community of each soil subsample and PCR amplification was performed by using the small subunit (18S) rDNA, as diagnostic marker, for nematode species discrimination. The 300 sequences available at this moment are still under characterisation. Sequencing of further 18S amplicons is also in progress.