Blossom end enlargement (BEE) is a postharvest deformation that may be related to the influx of photosynthetic assimilates before harvest. To elucidate the mechanism by which BEE occurs, expression marker genes that indicate the physiological condition of BEE-symptomatic fruit are necessary. First, we discovered that preharvest treatment with a synthetic cytokinin, N-(2-Chloro-4-pyridyl)-N’-phenylurea (CPPU), promoted fruit growth and suppressed BEE occurrence. This suggests that excessive assimilate influx is not a main cause of BEE occurrence. Subsequently, the expression levels of seven sugar-starvation marker genes, CsSEF1, AS, CsFDI1, CsPID, CsFUL1, CsETR1, and CsERF1B, were compared among symptomatic and asymptomatic fruits, combined with and without CPPU treatment. Only CsSEF1 showed a higher expression level in asymptomatic fruits than in symptomatic fruits, regardless of CPPU treatment. This was then tested using fruits stored via the modified-atmosphere packaging technique, which resulted in a lower occurrence of BEE, and the asymptomatic fruits showed a higher CsSEF1 expression level than symptomatic fruits, regardless of the packaging method. CsSEF1 codes a CCCH-type zinc finger protein, and an increase in the expression of CsSEF1 was correlated with a decrease in the fruit respiration rate. Thus, CsSEF1 may be usable as a BEE expression marker gene.

Anoectochilus formosanus is a rare medicinal plant with anti-inflammatory, antioxidant, hepatoprotective, and immunomodulatory properties. Its morphological growth and accumulation of medicinal compounds are strongly influenced by environmental factors such as light intensity. To investigate the physiological and ecological responses of Anoectochilus formosanus to varying light intensities, we examined physiological, morphological, and growth parameters across different growth stages under five different light intensities. Correlation, plasticity, and principal component analysis (PCA) were performed. The results showed that high and low light intensities altered physiological and biochemical indicators at different stages. Leaf area, fresh weight, dry weight, stem thickness, and non-photochemical quenching (NPQ) increased with increasing light intensity, whereas chlorophyll fluorescence parameters (Fv, Fm, and Fv/Fm) and flavonoid content decreased, reflecting reduced light capture and consumption under high light intensities. The phenotypic plasticity index of the morphological traits (0.5), indicating a greater plasticity of the photosynthetic traits. Biomass indicators—leaf area ratio and relative growth rate—were strongly correlated, driving the response to light intensity. Growth and biomass allocation peaked at moderate light intensity (70 μmol·m⁻²·s⁻¹). These findings highlight the conservative strategy employed by A. formosanus for slow carbon use under low-light conditions, and the adventurous strategy employed for rapid carbon use under strong light, offering insights into efficient cultivation practices.