Abstract: To elucidate the patterns of mineral element accumulation during fruit development in mangrove plants, we measured the concentrations of Na, K, Ca, Mg, and Cl throughout fruit development of five Sonneratia species from Qinglan Harbor, Hainan, China. Power-function models were used to analyze the relationships between mineral element concentrations, total contents, and fruit mass. The results showed that the concentrations of all mineral elements decreased with increasing fruit mass, whereas their total contents continuously increased. There were significant allometric relationships between total mineral element content and fruit mass, all exhibiting negative allometry (0.61<b<0.93), indicating that mineral element accumulation increased at a slower rate than fruit mass. Different functional mineral elements displayed distinct allocation patterns. Ca exhibited relatively conservative allocation, whereas the osmoregulatory elements Na, K, and Cl showed greater plasticity. In addition, Cl and Mg exhibited pronounced interspecific variation. These findings demonstrate that mineral element accumulation during fruit development in Sonneratia generally follows negative allometric growth patterns. The differential allocation strategies of functional mineral elements reflect trade-offs between structural construction and salt-adaptation requirements, suggesting that mineral element allocation during the propagule stage may contribute to the adaptation of mangrove plants to saline environments.

Key words: mangrove, propagule development, allometric relationship, mineral element allocation, salinity adaptation