This study showed that there was a wide variation in polyphenolic and quality traits between blueberry genotypes
and species. We found that highbush (V. corymbosum) cultivars share many characteristics, as do rabbiteye (V. virgatum)
cultivars, but the two species show distinct differences. The former is early ripening, lower in anthocyanins and
other polyphenols, and has very variable fruit weight, size and SSC/TA values. The latter is late ripening, higher in
anthocyanins and polyphenols, with consistently small fruit and SSC/TA values. These differences mean that cultivars
from each species need to be targeted to different markets and applications. For example, V. virgatum cultivars could
be marketed as “high health” based on their high anthocyanin content, especially ‘Dolce Blue’ and ‘Centurion’. Since
growers cannot grow both an early- and a late-maturing cultivar, with similar characteristics to extend the harvesting
season, consumers may notice some inconsistency with fruit size and quality over the season. This inconsistency
could mean more acidic fruit in December, but sweeter later in the season, firm and soft fruit, large and small berries.
The combination of cultivars in this study was designed to offer the widest possible harvest window; however, it
gives high variation in fruit quality.
Even though it was not the primary objective of this paper, the information collected may also help to identify
sources of breeding material for improving traits (e.g., increasing polyphenol content, or fruit firmness). The diversity
in these fruit traits presents a great opportunity for genetic improvement of blueberry through breeding programmes
(selection cycles), especially the traits that are not affected by seasonal variation (e.g. all the traits in our study with
the exception of TPH, FRAP, CA and Q). In addition to this, when there is no seasonal variation, some fruit traits
could be evaluated at an early stage of selection as found previously [28, 29]