Genetic identity of common buckwheat (Fagopyrum esculentum Moench) landraces locally cultivated in the Alps

The conservation of landraces in Europe is challenging because very often they have already disappeared or cannot be properly identified, which in turn prevents any possibility for their utilization. This work deals with the collection of molecular and historical data to identify and study the original landraces of common buckwheat (Fagopyrum esculentum Moench), locally cultivated in Northern Italy (Valtellina) and to date surviving among other commercial varieties, recently introduced in the same areas of the Alps. As plant materials of F. esculentum, we analyzed a number of Italian accessions along with two foreign accessions from Poland and Nepal, for a total of 174 individuals. Molecular investigations were based on a set of eight nuclear SSR marker loci. The mean observed heterozygosity over all accessions was equal to Ho = 0.466, being significantly lower than the expected heterozygosity (He = 0.764). A major finding was the recognition of a marked inbreeding rate (Fit = 0.387) and a reduced fixation index (Fst = 0.061), indicating that most genetic variation is found within populations. A significant overall gene flow among accessions was found (Nm = 3.846). Results indicated that only two of the examined accessions, the so-called “Nustran” and “Curunin”, could be considered, authentic Valtellina landraces. On the basis of results, we successfully developed a multi-locus marker system and identified a number of co-dominant marker alleles suitable for genetic traceability and authenticity certification of a “Nustran” and a “Curunin” autochthonous landraces of Valtellina and its food derivatives (i.e., Pizzoccheri, Polenta taragna).