实心瓜多竹竹材纤维和导管分子的变异规律

为了探明实心瓜多竹Guadua amplexifolia纤维和导管分子的变异规律，将竹秆沿纵向分为基部、中部和梢部，将竹壁沿径向取试样1个·mm^-1，进行纤维和导管分子长度和宽度的比较研究。结果表明，纤维长度分布范围为1 738 ～ 2 764 μm，宽度范围为13 ～20 μm，长宽比为91 ～ 211。导管分子长度分布范围为383 ～ 526 μm，宽度范围为99 ～ 288 μm，长宽比为1.3 ～ 4.4。纵向上，基部纤维长度和长宽比小于中部，中部小于梢部；纤维宽度与长度和长宽比变化规律相反。径向上，纤维长度和长宽比从竹壁内壁到竹壁厚度2/3处缓慢增加，之后有减小的趋势；纤维宽度在基部和中部处无明显的径向变化趋势，但在梢部，竹壁中部的纤维宽度明显大于靠近竹壁外壁和内壁处。纵向上，导管分子长度无明显的变化规律；基部宽度大于中部和梢部，中部和梢部之间无明显差异；长宽比变化规律与宽度相反。在径向上，长度无明显的变化规律；宽度从竹壁内壁到外壁有明显的降低趋势；长宽比从竹壁内壁到竹壁中部处无明显变化趋势，但自竹壁中部到外壁处有明显的增加趋势。图6表2参14

Variation in fiber and vessel elements of Guadua amplexifolia bamboo

To determine variation in fiber and vessel elements with respect to positions along the longitudinal direction （bottom, middle, and top of the culm） and the radial direction （from the inner part to the outer part of the culm wall） of Guadua amplexifolia, the length and width of fiber and vessel elements were measured. Results showed that fiber and vessel elements were varying in length from 1 738 to 2 764 μm and from 383 to 526 μm, in width from 13 to 20 μm and from 99 to 288 μm, and in ratios of length to width from 91 to 211 and from 1.3 to 4.4. For the culm, fiber length and ratio of length to width were in the order： bottom middle top, but fiber width was reversed （bottom middle top）. In the radial direction, fiber length and ratio of length to width increased first and then decreased gradually. Fiber width in the bottom and middle of the culm did not vary, whereas in the top of the culm it was higher for the inner and outer parts. In the longitudinal direction, there was no variation in vessel element length; for vessel element width, the bottom, compared to the middle and top, was higher even if there was no variation between the middle and top, but for the length to width ratio, the reverse was true. In the radial direction, there was no variation for vessel element length, the width of the vessel elements decreased, and there was no variation for the length to width ratio of vessel elements from the inner to the middle part; however, there was an increase from the middle to the outer part of the culm wall.