Characteristics of silicon and phytolith distribution in bamboo (Ferrocalamus strictus): variations between different organs and ages

Silicon (Si) is the second most abundant element in soil. It is absorbed and biomineralized as diverse forms of phytoliths in the plant organs. The paper investigated the silicon variation and phytolith morphology in different organs of Ferrocalamus strictus in different growth stages. The results showed that the silicon content in different organs of F. strictus varied greatly, ranged from 4.49 to 173.16 g kg−1, and increased in the order of leaf > sheath > branch > root > rhizome > culm. Correlation analysis showed that the silicon content in various organs was positively correlated with bamboo age. 24 phytolith morphotypes were observed in F. strictus, which varied closely interrelated with the organs and bamboo age. Branch, culm, root and rhizome were dominated by compound phytolith. The phytolith in leaf was relatively abundant and were dominated by bilobate, long saddle, two-spiked rondel, stomata phytoliths. The phytolith index of the 3-year leaf was less affected by climate and was relatively stable, which could be used to estimate leaf transpiration and environmental conditions. This work will enrich the phytolith morphology in Gramineae, and provide a basis for bamboo phytolith classification and analysis.