Phytolith Concentration and Morphological Variation in Dendrocalamus brandisii (Munro) Kurz. Leaves in Response to Sodium Silicate Foliar Application Across Vegetative Phenological Stages

This study investigated the effects of the foliar application of sodium silicate (SS) on phytolith formations in Dendrocalamus brandisii (Munro) Kurz. leaves by analyzing the phytolith concentration, morphological parameters, and assemblage compositions across leaves of varying ages and different phenological stages. The results showed that SS significantly increased the phytolith concentration in D. brandisii leaves, showing a trend of old leaves > mature leaves > young leaves. The concentration of phytoliths was the highest at the late shooting stage (November) and the lowest at the dormancy stage (January). August (shooting stage) and May (branching and leafing stage) were the critical periods for phytolith formation and the size and morphological variation. Sodium silicate significantly increased the proportion of saddle, bilobate, and stomatal phytoliths, which might help optimize the silicified structure of leaf epidermal cells and enhance the leaf resistance and light energy utilization efficiency. The results help clarify the mechanism of phytolith formation in different phenological periods of D. brandisii and provide a theoretical basis for the efficient use of silicon fertilizers in bamboo cultivation.