Using AFLPs to determine phylogenetic relationships and genetic erosion in durum wheat cultivars released in Italy and Spain throughout the 20th century

Genetic similarity between cultivars was studied by AFLP markers through the calculation of the Dice's coefficient. The results showed a high degree of genetic similarity between the old Spanish cultivars and the collection of Italian cultivars, suggesting that wheat could have been introduced in the Iberian Peninsula via Italy. Genetic diversity estimates based on AFLP data confirmed the maintenance of genetic diversity with time since the values of Polymorphic Information Content were 0.27 for old cultivars (released before 1945), 0.28 for intermediate cultivars (released between 1950 and 1985) and 0.29 for modern cultivars (released between 1988 and 2000). These results indicate that genetic variability in Italian and Spanish durum wheat seems to have been maintained quite constant throughout the breeding process over the last century.