This study evaluated the storability of ‘Eureka’ blueberry under different temperature conditions, identified the primary postharvest pathogens, and characterized their growth dynamics across a temperature gradient. Harvested ‘Eureka’ blueberry fruits were stored at 0 °C, 5 °C, 10 °C and 20 °C, respectively, with determinations of respiratory rate, total soluble solids (TSS) content, fruit firmness, decay rate and weight loss rate carried out during storage. Results showed that ‘Eureka’ blueberry exhibited typical physiological traits of non-climacteric fruits, as evidenced by the absence of a respiratory climacteric during postharvest storage. Within the temperature range of 0–20 °C, the TSS content and fruit firmness remained relatively stable, showing no significant response to temperature fluctuations. In contrast, both weight loss rate and decay rate increased markedly with rising temperatures, which were identified as the dominant factors contributing to postharvest losses of ‘Eureka’ blueberry. Three pathogenic fungi were isolated from decayed fruits and identified as Botrytis cinerea, Penicillium expansum and Penicillium crustosum through a combination of morphological observation, pathogenicity testing and molecular characterization by multi-gene analysis. In vitro culture assays on potato dextrose agar (PDA) plates revealed that the appropriate temperature range for mycelial growth of B. cinerea was 5 - 25 °C, while spore production was maximized at approximately 25 °C. For P. expansum and P. crustosum, the appropriate temperature range for both mycelial growth and spore production was 10 - 30 °C, with P. expansum showing slightly higher sensitivity to the upper limit of this range (30 °C) compared with P. crustosum. Both in vivo and in vitro experiments demonstrated that low-temperature storage at 0 °C significantly inhibited mycelial growth and spore production of the three pathogens, thus suggesting 0 °C as the optimal temperature for long-term preservation of ‘Eureka’ blueberry. However, the low relative humidity (RH) typically associated with 0 °C storage tends to accelerate fruit weight loss. Therefore, we propose that 0 °C storage integrated with moisture-retaining measures is a promising strategy for the postharvest handling of ‘Eureka’ blueberry in commercial production.
苏迎媛 et al. (Fri,) studied this question.