Estimation of genetic parameters and gains for color traits of strawberry

An investigation of strawberry (Fragaria x ananassa Duch.) fruit and juice color dimensions (L* a* b*) was conducted to estimate genetic parameters and determine breeding strategies for improving fruit color in the University of Florida strawberry breeding population. The genetic analysis was conducted using clonally replicated seedlings from a factorial mating design with additional biparental crosses and was evaluated in two locations. Substantial additive and non-additive genetic variation was described for most traits. Low genotype by environment interactions indicate that color evaluations may be conducted in either of the two test locations. Consistent with previous reports, genetic correlations indicated that internal and external fruit colors are under separate genetic control. Colorimeter a* and L* values described the same information for internal color in that internal flesh that was darker in color also appeared more red. A method was developed to reliably measure a* and L* for small (2 ml) samples of strawberry juice. Juice a* had significant genetic correlations with internal a* and may be used as a correlated trait to improve the internal redness of the fruit. However, pigments from the external tissues of the fruit appear to also impact the L* value of strawberry juice, complicating the effects of selection on juice color traits.