Identification and characterization of ancient Italian chestnut using nuclear microsatellite markers

The presence of the chestnut (Castanea sativa Mill.) in all Italian regions, within altitude limits dependingon latitude, and in very different exposure and soil conditions, favored the formation of a rich patrimonyof cultivars. In the course of several centuries of cultivation a number of genotypes appeared and wereselected, also by virtue of a widespread habit of propagating the tree by seed; these genotypes differ fornumerous traits, particularly for those relating to the fruit, but plant resistance to biotic and abiotic factorshas been important in the selection process. However, the large existing genetic patrimony is increasinglyat risk of genetic erosion and it is extremely important to study and valorize local germplasm in order topreserve the existing biodiversity and to identify potentially useful characters for a revival of the Italianchestnut industry. The purpose of this study was to characterize genetically, with eight nSSR (di- andtrinucleotide, CsCAT and EMCs series respectively) markers, 54 ancient chestnut accessions widespreadin a small area of Northern Italy.The set of chosen markers resulted as a whole highly polymorphic, and made possible the character-ization of all studied accessions. The use of only three markers allowed the identification of 28 distinctgenetic profiles. Data were analyzed by cluster analysis, and results demonstrated a vast genetic vari-ability within the population. The nSSR used, moreover, allowed us to identify most unknown accessionsand possible homonyms and synonyms, and cases of intravarietal clones within the local germplasm.