Investigating Factors Affecting Suaeda salsa Leaf Color Phenotype Based on Response Surface Methodology

Purpose To investigate the main factors affecting the leaf color variation of Suaeda salsa in the Liaohe Estuary.

Methods Using Box-Behnken response surface design, three types of substrates (sea sand, loam, and sea mud) with different compactness levels were set up, combined with 0, 100, and 300 mmol/L NaCl treatments, for a total of 17 pot treatments, with three replicates for each treatment. The affecting factors of S. salsa leaf color phenotype were analyzed by observing substrate particles under scanning electron microscope and determining the contents of total chlorophyll and betacyanin in leaves.

Results NaCl concentration significantly affected the contents of total chlorophyll and betacyanin, while substrate type and compactness had minimal effects on pigment accumulation. However, under high salinity condition, sea mud and low compactness substrates favored betacyanin accumulation.

Conclusion Salinity is the main factor affecting the leaf color variation of S. salsa. High salinity promotes betacyanin accumulation and inhibits chlorophyll synthesis, while the substrate type and compactness play secondary regulatory roles in pigment distribution.