Assessing genetic diversity in Italian goat populations using AFLP (R) markers

Amplified fragment length polymorphism (AFLP(R)) markers were used to inves tigate the genetic variation in a sample of seven goat (Capra hircus) popul ations. A total of 210 individuals (30 per population) were analysed using seven selected AFLP primer combinations that produced 219 clear polymorphis ms. Four autochthonous goat breeds (Bionda dell'Adamello, Frisa, Orobica an d Verzaschese), two primary populations, one from the Lombardy Alps (Val di Livo) and the other from Sardinia island (Sarda) and a reference cosmopoli tan breed (Saanen) were included in the analysis. The expected heterozygosi ty (Het) did not differ significantly among breeds (range 0.21-0.24). No br eed specific markers were identified. The variability at AFLP loci was larg ely maintained within breeds, as indicated by the coefficient of genetic di fferentiation (Gst) value (0.11). Dice similarities calculated between pair s of individuals belonging to the same or to different breeds largely overl apped. Bootstrapping on markers indicated that the coefficient of variation (CV) of the genetic indexes tested decreases only marginally by adding mar kers over 100 AFLPs. Cluster analysis based on standard genetic distance be tween breeds indicates that Sarda is the most distant population, while Bio nda, Frisa, Verzaschese and Val di Livo seem to be highly related populatio ns. Interestingly, Saanen is closer than Orobica to the other four goat pop ulations of the Lombardy Alps. Principal co-ordinates analysis based on Dic e similarities confirms these observations. Genetic diversity or the goat p opulations investigated confirms what is expected on the basis of their geo graphical location. Results from Orobica are not correlated with geographic al distances and may reflect undocumented migrations and gene flows and ide ntify an original genetic resource.