ALLOZYME VARIATION WITHIN AND AMONG CULTIVATED VARIETIES OF SWEET CHESTNUT (CASTANEA-SATIVA)

Sweet chestnut (Castanea sativa Mill.) is a species that has been cult ivated and propagated through grafting for a long time in Italy and So uthern European countries. The genetic variability within and among di fferent varieties was analyzed by means of starch gel electrophoresis. Twenty cultivated varieties originating from three different areas lo cated in northern, central, and southern Italy, were analyzed at six p olymorphic enzyme gene loci. Our results show a relatively high degree of homogeneity both among individuals of the same variety and among v arieties of the same area; on the other hand, high values of genetic d istance were found among different geographic areas. The agamic propag ation method of this species may have caused a reduction of the geneti c diversity within varieties. The causes and consequences of the loss of genetic variation in these varieties are discussed.