CONTENT, COMPOSITION AND BIOSYNTHESIS OF ANTHOCYANINS IN FRUITS OF DIFFERENT FRAGARIA L. GENOTYPES (REVIEW)

The colour of strawberry fruits is the most important feature influencing consumer preferences and can vary from white to light orange and from scarlet to almost black. It is necessary to study the total content, composition and regulation of anthocyanin biosynthesis in different Fragaria species. This will facilitate the development of anthocyanin-rich strawberry cultivars to meet the growing demand for health-promoting compounds in the human diet. The purpose of the work was to highlight the latest achievements in studying the specifics of the anthocyanin profile in fruits of different Fragaria genotypes, issues of anthocyanin biosynthesis and decoding of structural and regulatory genes involved in the formation of fruit color. The anthocyanin content in strawberry cultivars, according to data obtained by Russian and foreign researchers, averages 48.0 ±3.8 mg/100 g and varies from 3.6 mg/100 g to 171.6 mg/100 g. The relative proportions of different anthocyanins can have a significant effect on fruit colour: pelargonidin derivatives give fruits a bright red colour, while cyanidin derivatives give fruits a dark red colour. In the garden strawberry the predominant anthocyanin is pelargonidin-3-glucoside; the second most abundant anthocyanin is pelargonidin-3-malonyl glucoside; cyanidin-3- glucoside is present in smaller amounts. Cyanidin-3-glucoside chloride, cyanidin-3- galactoside and cyanidin 3-glucoside were determined in the fruits of F. pentaphylla and F. nilgerrensis. Cyanidin-3-glucopyranoside is the most abundant anthocyanin in F. chiloensis fruits. The fruits of F. vesca accumulate mainly cyanidin glucosides. It has been established that the MYB10 protein (encoded by the FaMYB10 gene) is a transcription factor for anthocyanin biosynthesis in strawberry fruits. Various loss-offunction mutations of the FaMYB10 gene impair anthocyanin biosynthesis and cause much of the color variation observed in wild and cultivated strawberries.