MORPHOLOGY OF PHYTOLITH IN BAMBUSOIDEAE (GRAMINEAE) AND ITS ECOLOGICAL SIGNIFICANCE
竹亚科植硅体形态学研究及其生态学意义

Phytolith analysis has been widely used in many scientific research fields such as Botany, Agriculture, and Environmental Archaeology. Different plants produce distinguishable phytoliths with different shapes and relative content percentages, and so do different genera or species within the same family and/or subfamily, particularly in Gramineae. Comprehensive morphological research on phytoliths has been carried out on leaf-blades from 64 species belonging to 19 genera in the subfamily Bambusoideae (Gramineae). It reveals that there are several types of phytoliths in bamboos including fan-shape, long-saddle, tower-shape, sinuate elongate, smooth elongate, silica stoma, silica hair and hair tip, among which long-saddle phytolith is diagnostic for Bambusoideae. To find out the relationship between phytoliths and ecotypes of bamboos, long-saddle phytoliths from each bamboo species are measured to get morphological parameters such as length, width, and height as well as the amount of silica granules on the surface. Based on the classification of four ecotypes from different bamboos at genus level, these observations reveal that the average size of long-saddle phytoliths from sympodial scattering bamboos is the largest (Length: 20.6±0.2m, Width: 12.8±0.5m, Height: 12.4±0.1m, Granule Amount: 2.8±0.5), with monopodial scattering bamboos closely followed (L:18.8±0.8m, W:11.7±0.4m, H:11.8±0.3m, GA:1.9±0.1), then followed by the compound mixed bamboos (L:18.3±1.5m, W:11.2±1.5m, H:11.4±1.7m, GA:1.8±0.4), and the average size of long-saddle phytoliths in sympodial caespitose bamboos is the smallest (L:18.0±1.8m, W:9.7±0.5m, H:10.1±1.4m, GA:2.6±0.3). Further discriminant analysis on morphological varieties of long-saddle phytoliths also plot out these four ecotypes. In addition, the relationship between long-saddle phytoliths and the habitat of Bambusoideae is also discussed in the subfamily Bambusoideae.