Univ Talca, Inst Ciencias Biol, Talca, Chile.Herrera, R (Herrera, Raul)Fragaria chiloensis ssp. chiloensis has two native botanical forms. Fruits from both botanical forms, Fragaria chiloensis ssp. chiloensis f. chiloensis (native white strawberry) and f. patagonica (native red strawberry), were collected from Bio-Bio Region, and a comparative study in the biosynthesis and pigment accumulation was performed from achens. The fruit was classified in four different developmental and ripening stages in order to establish the differences in the transcriptional profile of structural genes and the chemical compounds. A differential expression of those genes involved in the biosynthesis (phenylpropanoid and flavonoids) of anthocianins was found. The differential expression of genes was concomitant with the increase in the level of cyanidin 3-glucoside (C3G) along the fruit development for both botanical forms. On the contrary, undetectable level of cyanidin 3-glucoside (P3G) was observed in the f. chiloensis. Albeit, P3G increase rapidly from the development stage 2, reaching the maximum value at stage 4 in Fragaria chiloensis ssp. chiloensis f. patagonica.