Variation of the Phytolith Content and Morphology in Dendrocalamus brandisii Leaf at Different growth Stages

In order to investigate the variation of phytolith content and morphotypes in Dendrocalamus brandisii at different growth stages, the silicon and phytolith contents in the leaves of D. brandisii at different culm ages and leaves of different growth stages at the same culm age were analyzed, and the phytoliths were observed and identified under microscope. The results showed the silicon content in D. brandisii leaves at different culm ages varied in the order of the 1^st-year（5.93%）< 2^nd -year（10.30%）<3^rd-year（15.25%）. The silicon content of the old leaves in each culm age group was significantly higher than that of mature and young leaves. The phytolith content demonstrated the same variation trend as that silicon content. Phytolith morphotypes in D. brandisii leaves at different growth stages were identical and grouped into six morphotypes, viz. acute bulbosus, blocky, elongate entire, bulliform flabellate, bilobate and saddle. The phytolith assemblage was all characterized by a high frequency of bilobate, elongate entire and saddle, accounting for more than 70% of the total. Except bilobate phytolith, the proportion of other five phytolith morphotypes increased with the increase of culm age. The variation for the size of bilobate and saddle phytoliths was insignificant, indicating bilobate and saddle phytoliths were considerably stable phytolith morphotypes.