Morphological and genetic diversity of European cranberry (Vaccinium oxycoccos L., Ericaceae) clones in Lithuanian reserves

The wild-harvested fruit of Vaccinium oxycoccos (European cranberry) is used medicinally in many European and North American countries; the plant, however, is seldom cultivated. In order to optimize the collection strategy and improve the horticulturally important characters of V. oxycoccos clones, comprehensive investigations of the species are necessary. In the present study we investigated the phenological, morphological and genetic diversity of 29 clones originating from two wild populations growing in two strictly protected Lithuanian reserves, Čepkeliai and Žuvintas. During an ex situ collection at Kaunas Botanical Garden, we observed great phenological variation between the collected V. oxycoccos clones. The following morphological traits most clearly distinguished our study clones: leaf size, berry shape, berry size and fruit colour at full maturity. The genetic variation of V. oxycoccos clones from the two populations was assessed using RAPD and SSR. RAPD analysis conducted with 9 primers resulted in 146 polymorphic loci for the total sample, and SSR analysis with 5 primers revealed 29 alleles for the total sample. A greater degree of polymorphism was demonstrated for the Čepkeliai population than for the Žuvintas population. The study allowed the selection of several clones having promising morphological traits for further testing in the field.