Pollen donor selection modulates fruit quality, bioactive profiles, and antioxidant capacity in ‘Fengtang’ plum (Prunus salicina): links to endogenous hormonal regulation

Cross-pollination is a common practice in plum cultivation to enhance yield. However, the influence of specific pollen donors on fruit quality attributes remains insufficiently characterized. Our study aimed to investigate the effects of different pollen donors on fruit quality, bioactive compounds, antioxidant capacity, and endogenous hormones during the development of ‘Fengtang’ plum. Compared to open pollination, artificial pollination with ‘Siyue’, ‘Fenghuang’, and ‘Yinhong’ pollen revealed distinct metaxenia effects. Pollen from ‘Siyue’ and ‘Fenghuang’ significantly increased fruit weight by 19.69% and 22.80%, respectively, while elevating the ascorbic acid and amino acid contents of ‘Fengtang’ plum fruits. By altering sugar and organic acid compositions, ‘Siyue’ and ‘Fenghuang’ pollen induced better fruit quality. The resulting fruits exhibited higher levels of sucrose, fructose, and sorbitol in the later stages of fruit development. ‘Fenghuang’-pollinated fruits had the lowest levels of quinic acid, oxalic acid, and shikimic acid. Conversely, ‘Yinhong’ pollen triggered a significantly higher accumulation of total phenolics, flavonoids, proanthocyanidins, and flavonols. Significant differences were observed among the 13 individual phenolic compounds throughout fruit development after pollination. Notably, ‘Yinhong’ pollen enhanced radical scavenging capacity, while ‘Fenghuang’ pollen elevated antioxidant enzyme activities. Pollen donors significantly altered endogenous hormone levels during fruit development of ‘Fengtang’ plum. Principal component analysis and correlation analysis revealed that these pollen-mediated differential effects showed strong correlations with endogenous hormones, including auxins, gibberellins, zeatin, abscisic acid, and ethylene. In summary, different pollen donors exerted differential effects on fruit quality, bioactive compounds, and antioxidant capacity in ‘Fengtang’ plum. This pollen-mediated effect was associated with the regulation of endogenous hormones. This work provides crucial insights into the metaxenia effect and practical guidance for selecting appropriate pollinizer cultivars in commercial plum production.