Page 19 - Dedola2011

Results

ISSR
The number and size of bands resolved per primer ranged from ten to 11 and from 500
bp to l ,800 bp, respectively (Table 2). The Bayesian model-based clustering analyses
showed a greater degree of genetic structuring in the SCR group, whereas less genetic
differentiation was found in the region encompassing the SAS group (Fig. 2a, b). The
uppermost hierarchicallevel ofgenetic structuring (as estimated from the first round of
STRUCTURE analyses) resulted in a clustering solution ofK = 3: cluster A
corresponded to samples from North-Westem Sardinia (with the exception ofone
specimen from Isola dei Porri and those from Argentiera, which were grouped in cluster
B); cluster B corresponded to samples from Corsica, North-Eastern Sardinia, Argentiera
and one specimen from Isola dei Porri; cluster C corresponded to samples from the SAS
group (Fig. 2a).

The second and third round of STRUCTURE analyses (overall K = 7 and K =

10, respectively) showed a further substructuring that was highly consistent with the
clustering solution found by BAPS analysis (Fig. 2b), which identified eight genetic
clusters, seven of which corresponded to groups of individuals found after the third
round of STRUCTURE analyses (Fig. 2a). The results from both analyses showed a
clear spatial genetic structuring in North-Western Sardinia, where cluster A was
partitioned in subclusters corresponding to Asinara Island, Coscia di Donna, Mal di
Ventre Island, and Isola dei Porri (except one specimen) (Fig. 2a, b). Furthermore,
cluster B was partitioned in subclusters corresponding to the samples from Corsica and
the samples from North-Eastern Sardinia, which formed two further groups (Fig. 2a, b).

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Gìan Luca Dedola: ANALISI DELLA VARIABILITÀ GENETICA DI PATELLA FéRRUGINEA, PATEL-LA ULl'SSIPONENSIS (MOLLUSCA: GASTROPODA) E PINNA
NOBILIS (MOLLUSCA: BIVALVIA): lLCONTRJBUTO DEl DATI MOLECOLARI ALLA CONSERVAZIONE DI SPECIE MINACCIATE- Tesi di douorato in Scienze
della natura e delle sue risorse • indiri7.zo BK>logi.a Ambientale, Università degli Studi di Sassarl