## 3 Results and Discussion
### Impact of Temperature and Global Radiation on Cultivar-Specific Anthocyanin Profiles  
As shown by the PC analysis, the synthesis and accumulation of total and individual anthocyanin were influenced by temperature (T\({}_{\text{mean}}\), T\({}_{\text{max}}\) and T\({}_{\text{min}}\)) and global radiation and its interactions, being altogether affected by the latitude of the growing location. Environmental factors changing with latitude are mainly photoperiod, quantity and spectral composition of the solar radiation [17], as well as air temperature being indirectly dependent on solar radiation. However, weather conditions may vary between seasons at site and during the harvest period. Consequently, linear regression analyses were assessed to better explain the dependency of the cultivar-specific anthocyanin synthesis and accumulation on T\({}_{\text{mean}}\), T\({}_{\text{max}}\), T\({}_{\text{min}}\) and global radiation. Moreover, to evaluate the effective time span of these factors, they were summarized 3, 5, 10 and 15 days prior to harvest. Overall, the percentage of variations (Figure 5), explained by these environmental factors, were rather low with some exceptions (highest R\({}^{2}\) = 0.62), highlighting again, the genotype specific-based anthocyanin syntheses. For example 'Gariguette' and 'Clery', with the exception of cya-3-mal-glc, were not affected by the environmental factors tested. For 'Clery', this result supports previous studies showing also no or little environmental effects on anthocyanin accumulation in fruits from this cultivar, when grown at three locations from North to Central Europe [21], and at different altitude in Switzerland [31]. In contrast, 'Florence','Frida' and 'Sonata' reacted most sensitively, but differently, to the pre-harvest temperature and global radiation conditions. For these cultivars, in general, (T\({}_{\text{max}}\)) had a higher impact on the syntheses of the less abundant anthocyanins cya-3-glc, pel-3-rut, cya-3-mal-glc, pel-3-mal-glc and on the total anthocyanin, than the minimum temperature. Thereby, the influence of T\({}_{\text{max}}\) often seemed to be stronger than the related T\({}_{\text{mean}}\) itself (for example, for the cya-derivates in 'Florence' and 'Frida'). Only the synthesis of pel-3-glc, the main anthocyanin of strawberry, was slightly more influenced by T\({}_{\text{min}}\) than by T\({}_{\text{max}}\). In the current study, global radiation was positive correlated with cyl-3-glc and pel-3-rut only in fruits of 'Frida'. Noticeable is the contrasting behavior of 'Candonga' shown as the only cultivar with a negative relationship between global radiation and the main anthocyanin pel-3-glc (R\({}^{2}\) = 0.38 \(-\) 0.44), and thus also to the related total anthocyanin, and between cya-3-mal-glc and T\({}_{\text{min}}\). 'Candonga' was bred and selected for tunnel production in Spain, which is the common production system for that area. Therefore, it is assumed that protection against UV-radiation was not an important growing factor for this genotype. In a Spanish study performed in tunnels, no correlation was found for 'Candonga' between total anthocyanin and T\({}_{\text{mean}}\), T\({}_{\text{max}}\) and solar radiation and, in contrast to this study, a positive relationship to T\({}_{\text{min}}\)[14]. In the same study, however, other cultivars reacted also on T\({}_{\text{mean}}\) or T\({}_{\text{max}}\). Noteworthy also is the positive relationship between global radiation and the content of cya-derivates in the Scandinavian cultivar 'Frida'. Moreover, 'Frida', together with 'Florence'--bred in the United Kingdom--were both sensitive to T\({}_{\text{max}}\) with high R\({}^{2}\) values for cya-derivates and pel-3-rut, and in the case of 'Frida', also of pel-3-mal-glc. Thus, both cultivars showed a high adaption to their breeding locations to benefit best from T\({}_{\text{max}}\) in areas with, in general, lower temperature, and in case of 'Frida', also from the latitudinal long photoperiod in Norway.