Anthocyanins in wild relatives of strawberry (Fragaria L.)

Authors: Hummer, Kim; HOAI, T - Vietnam Academy Of Agricultural Sciences (VAAS); DURST, ROBERT - Oregon State University

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2021
Publication Date: 4/28/2021
Citation: Hummer, K.E., Hoai, T.T., Durst, R. 2021. Anthocyanins in wild relatives of strawberry (Fragaria L.). Acta Horticulturae. 1309:1063-1068. https://doi.org/10.17660/ActaHortic.2021.1309.150.
DOI: https://doi.org/10.17660/ActaHortic.2021.1309.150

Interpretive Summary: Fruit chemistry of wild relatives of strawberries (Fragaria L.) at the USDA National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, have not been well documented. The objective of this study was to examine profiles and total anthocyanin (red pigment) content of nine strawberry species, eight subspecies, and one outgroup, the wood strawberry. The profiles of these pigments were performed using high performance liquid chromotography (HPLC). The total anthocyanins were expressed as mg of anthocyanin/100 g of fresh fruit. The germplasm evaluated included the mountain strawberry, from the Oregon High Cascade Mountains, along with beach strawberries from Oregon, Hawaii, California and Chile; three subspecies of the Virginia strawberry from across the United States; four cultivated types, a European strawberry from Switzerland; and the Alpine strawberry the Japanese strawberry, the green strawberry from Europe, and the Nilger strawberry from China and Vietnam. The samples examined had varying amounts of typical strawberry anthocyanins. In addition, atypical anthocyanin peaks were observed in some samples, particularly the wood strawberry. Total anthocyanins ranged from 49.27 mg/100g fruit to about 1 mg/100g fruit or less for white-fruited types. The wood strawberry fruit had between 89 to 95% atypical anthocyanins. The total anthocyanin concentration of the Cascade strawberry had typical anthocyanins. White fruited types contained the three compounds, though in lower amounts than red fruited cultivars. The Nilger strawberry had white fruit with trace amounts of pigment. While reports have been published determining anthocyanin concentration of cultivated hybrid strawberries for food processing purposes, further work is needed to examine anthocyanin profiles for diverse strawberry species.

Technical Abstract: Fruit chemistry of wild relatives of strawberries (Fragaria L.) at the USDA National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, have not been well documented. The objective of this study was to examine profiles and total anthocyanin content of 9 strawberry species, 8 subspecies, and one outgroup, Duchesnea indica L. Anthocyanin profiles were performed using high performance liquid chromotography (HPLC). The total anthocyanins were expressed as mg of anthocyanin/100 g of fresh-frozen fruit. The germplasm evaluated included recently collected F. cascadensis K.E. Hummer from the Oregon High Cascade Mountains, along with octoploid beach strawberries (F. chiloensis (L.) Mill. from Oregon, Hawaii, California and Chile; 3 subspecies of F. virginiana Mill. from across the United States; 4 cultivated examples of F. × ananassa; the hexaploid, F. moschata Duschesne from Switzerland; and the diploids F. vesca L. from California and Nova Scotia, F. nipponica Makino from Japan, F. viridis Duschesne from Europe, and F. nilgerrensis Schltdl. Ex J. Gay from China and Vietnam. The samples examined had varying amounts of typical strawberry anthocyanins, cyanadin-3-glucoside (Cy 3-gluc), pelargonidin 3-glucoside (Pg 3-gluc), and pelargonidin-3-rutinoside (Pg 3-rut). In addition, atypical anthocyanin peaks were observed in some samples, particularly Duchesnea. Total anthocyanins ranged from 49.27 mg/100g fruit (F. moschata L. with Cy 3-gluc as the primary peak) to about 1 mg/100g fruit or less for white-fruited types. Duschesnea indica fruit had between 89 to 95% atypical anthocyanins, though Cy 3-gluc Pg 3-gluc and Pg 3-rut were present in reduced quantities. The total anthocyanin concentration of Fragaria cascadensis included Pg 3-gluc > Cy 3-gluc, without Pg 3-rut, though having only 2 to 6 % atypical anthocyanins. White fruited types contained the three compounds, though in different ratios than red fruited cultivars. Fragaria nilgerrensis had white fruit with trace amounts of Cy 3-gluc > Pg 3-gluc > Pg 3-rut. While reports have been published determining anthocyanin concentration of cultivated hybrid strawberries for food processing purposes, further work is needed to examine anthocyanin profiles for diverse strawberry species.