Proteomic variation is as large within as between strawberry varieties

in search for a strawberry (Fragaria ananassa) with low allergen content, we determined the proteomic variation within and between different varieties. Proteomics data were generated by DIGE and proteins identified with MALDI-MS/MS. The amount of the strawberry allergen Fra a 1 varied between different strawberry varieties (CV = 39%). The variation was at the same level, or even slightly larger, due to different growth conditions (CV = 43%). For 153 other proteins, the biological variation was more affected by different growth conditions than by different varieties (mean CV = 52% and 43%, respectively) due to variation in a subset of proteins. Thus, the allergen variation due to growth conditions must be taken into consideration in attempts to obtain a low-allergen strawberry. However, the allergen content was always lower in colorless (white) strawberry varieties than in the red ones. Moreover, of the spots whose expression correlated with the allergen and the color (32 and 68, respectively), only 3 were the same. This implies that these two phenotypic traits are not inseparable, and it may be possible to breed a red strawberry with low amount of allergen.