Variation in concentration and composition of anthocyanins among strawberry cultivars

Japanese and European strawberry (Fragaria × ananassa Duch.) cultivars were analyzed for their differences in their concentration and composition of anthocyanins. Within a fruit, the concentration of total anthocyanins is higher in epidermal tissues than in inner cortex or pith for all cultivars, but among cultivars, differences in the concentration were greater in the inner flesh compared to the epidermal tissues. The pigment in inner flesh was significantly less concentrated in the newly released Japanese cultivars than in the European cultivars, ‘Elsanta’ and ‘Darselect’, or the old Japanese cultivar ‘Hokowase’. Pelargonidin 3-glucoside was the predominant pigment except for achenes. In achenes, the compositions of cyanidin derivatives and malonylated anthocyanins were extremely high compared to the other tissues. Considerable amounts of cyanidin 3-malonylglucoside, which has not been reported previously and pelargonidin 3-malonylglucoside occurred in achenes of all cultivars. The epidermal tissues of ‘Toyonoka’, ‘Sachinoka’ and ‘Ai-Berry’ contained only a trace level of malonylated anthocyanins; the achenes also had low concentration of the pigments compared to other cultivars. With these results, the functions and expression of Amg, the single dominant gene that supposedly controls the synthesis of malonylated anthocyanins in the strawberry receptacle, are discussed.