Inter- and intra-seasonal changes in anthocyanin accumulation and global metabolite profiling of six blueberry genotypes

Abstract

Anthocyanin content in six blueberry genotypes was evaluated across two harvest seasons. Three southern highbush (hybrids of Vaccinium corymbosum) genotypes (Legacy, Sampson, SHF2B1-21:3) showed a dramatic and almost linear increase in total anthocyanin content across each harvest season, with an increase of up to 20mg/g dry weight (DW). The three rabbiteye (V. virgatum) genotypes (Ira, Montgomery, Onslow) showed no trend in anthocyanin content, fluctuating by up to 15mg/g DW. The relative proportions of each individual anthocyanin were also investigated. Rabbiteye genotypes contained higher percentages of cyanidin glycosides than the southern highbush genotypes, while the reverse was found for the levels of delphinidin glycosides present. For southern highbush genotypes, the percentages of malvidin and delphinidin glycosides were inversely proportional across each harvest season. Principal component analysis on the data obtained by HPLC–MS of the crude extracts clearly separated rabbiteyes and southern highbush into two discrete sets based on global metabolite profiling. Within the southern highbush grouping, genotypes were easily distinguished from one another across each harvest season, due to their separation on the scores plot, indicating that each genotype had distinctly different metabolite profile, whereas each of the rabbiteye genotypes overlapped on the scores plot, indicating commonalities in metabolite profiles.