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To investigate the characteristics of photosynthetic physiological changes in leaves of Mangifera indica L. cv. Guifei under enhanced ultraviolet (UV)-B radiation, natural light-exposed trees were used as controls and 96 kJ·m⁻²·d⁻¹ enhanced UV-B radiation was artificially simulated in the field. The changes in fruit maturity and quality, the leaf net photosynthetic rate (P_n), photosynthetic pigment contents, photochemical reactions, the activities of photosynthetic enzymes and related gene expression levels were determined. Compared with the control, the percentage of mature fruits under the treatment significantly increased, and fruit quality improved. The net photosynthetic rate (P_n), photosynthetic pigment content, Hill reaction activity, and photochemical quenching coefficient (qP) of the treated leaves showed significantly higher values than those of the control leaves. The activities of Rubisco and Rubisco activating enzyme (RCA) and the expression levels of the Rubisco large subunit and Rubisco small subunit were significantly increased. Treatment with 96 kJ·m⁻²·d⁻¹ enhanced ultraviolet-B radiation improved Rubisco activity by increasing the expression of the Rubisco large and small subunit genes, thereby enhancing the CO₂-fixing capacity and dark reaction capacity of leaves. Thus, the net photosynthetic rate of leaves increased, which promoted the early maturity of ‘Guifei’ mango by the rapid accumulation of photosynthetic products.

Pumpkin (Cucurbita moschata Duch.) is a versatile crop with strong stress resistance and promising growth potential. Widely cultivated in various regions of China, it ranks among the top crops globally in terms of both planting area and consumption. Known for its pleasant taste and high nutritional value, pumpkin pulp is rich in essential trace elements for the human body. Even after harvest, pumpkin fruit remains metabolically active, requiring its own nutrients to complete the postripening process. Failure to provide proper postharvest storage conditions can lead to excessive water loss and rapid nutrient depletion, resulting in rough, shriveled, and even rotten peel, ultimately diminishing the economic value of the pumpkin. This study aimed to investigate the changes in pumpkin quality and physiological indicators during storage to provide insights to determine optimal consumption and processing periods of pumpkins. The pumpkins were stored at a temperature of 16 ± 2 °C and 60% to 80% humidity during the experiment. The dynamic changes in fruit quality, hardness, respiration rate, malondialdehyde content, level of antioxidant enzymes, and other indicators of two pumpkin cultivars (BM5 and JQ) were assessed during storage, and the correlation among these indicators was evaluated. The results indicated a decrease in the vitamin C content and pulp hardness, whereas the superoxide dismutase and catalase contents initially increased and then decreased, and malondialdehyde and weight loss rates increased over the storage period. The weight loss rate exhibited significant positive and negative correlations with the malondialdehyde content (P < 0.01) of the two cultivars, whereas the vitamin C content showed a significant positive correlation with pulp hardness (P < 0.01). The findings indicate that optimal fruit quality was maintained within 40 days of postharvest storage. This study provides valuable insights into the selection of storable pumpkin cultivars.