Seed, Germination, and Seed-Reserve Traits of Ephedra saxatilis Differ Along Different Altitudinal Gradients in Tibet, China

Ephedra saxatilis , an important medicinal plant species belonging to the genus Ephedra , grows at a wide range of altitudes in Tibet, China. Collect seeds with different altitude gradients at low altitude (3500–4000 m), medium altitude (4000–4500 m), and high altitude (4500–5000 m), and study the effects of different altitude gradients on seed morphological traits, germination parameters, Seedling morphology, the morphological changes in the process of seed germination and uncracked seeds, 11 biochemical variables related to seed storage. Use correlation analysis to test the relationship between these variables. The process of seed germination is divided into five stages. Seeds that did not change color in stage III did not continue to grow. Seeds from low altitudes had significantly higher percentage of germination, and water contents and reducing sugars contents, but longer germination time. Seeds from high altitudes, however, had higher Xanthophyll, soluble phenolic, and ash contents. Among the examined biochemical variables, the germination rate at different altitudes was positively correlated with vitamin E, water content, and total flavonoid and soluble protein contents. Seedling growth state is divided into five stages. Our results confirm that seed differed significantly across different altitudinal gradients. Seeds of E. saxatilis from low altitudes had a survival advantage over those from medium and high altitudes.