Objective To systematically investigate the developmental characteristics and mutual interactions of seeds in Citrus reticulsta Orah, as well as to analyze the relationships between seed quantity, distribution patterns, and shriveling phenomena. The study aims to uncover competitive mechanisms among seeds during their maturation process.

Method A comprehensive survey was conducted on the number of segments (9~11 segments) in Orah. Statistical methods and mathematical modeling were employed to analyze the relationship between seed quantity and the incidence of shriveling. Additionally, spatial distribution patterns of segments with varying seed quantities were examined, focusing on correlations among adjacent segments.

Result The study revealed that the number of seed segments in Orah is mainly concentrated between 9 and 11. Fruits with 11 segments exhibited higher total seed counts (17.63) compared to those with 9 segments (15.53, P < 0.01). However, the average number of seeds per segment was lower in the 11-segment group than in the 10-segment group (1.60 vs. 1.73, P = 0.08). This phenomenon was attributed to an increased proportion of segments containing shriveled or absent seeds. Further analysis revealed the following patterns during seed development: (1) As the number of seeds per segment increased from 1 to 4, the incidence of seed shrinkage rose significantly (8.23%, 23.77%, 21.32%, and 52.08%, respectively; P < 0.001), and the severity of shrinkage also increased (the combined percentage of moderately and severely shrunken seeds was 40.00% in single-seeded segments versus 83.00% in four-seeded segments; P < 0.05). (2) Segments with varying seed numbers exhibited a distinct alternating distribution pattern. This spatial arrangement was primarily random (r_mean ≈ 0.16), though correlations were observed between some adjacent segments.

Conclusion These findings indicate significant competitive relationships among seeds during the development and maturation of citrus fruits. The developmental patterns and mutual interactions of seeds in Orah are influenced by multiple factors. The competitive mechanisms among seeds significantly impact their distribution and quantity.