【摘要】 毛竹秆茎由“竹皮”系统、基本系统和维管系统组成。“竹皮”系统包括表皮、皮下层及皮层,为体小壁厚、排列紧密的细胞。基本系统包括基本组织和髓环。髓环为秆茎的内壁,由数至十数层高度木质化的石细胞组成,排列整齐而紧密。髓环与“竹皮”系统形成秆茎的内外夹壁,把基本组织和维管系统紧夹其中。节间维管束都平行排列,但通过竹节时则有不同程度的弯曲、分叉或合并,引起竹节肿胀,分枝节尤为明显。有些维管束向内迂回盘绕,与基本组织交织形成节隔,有利于竹株的横向输导和机械支持。更多还原

【Abstract】 A culm consists of the rind, basic and vascular systems. The rind system is com- posed of epidermis, hypodermis and cortex which are of small, thick-walled and well packed cells and mainly functions as an outer wall to protect the culm tissues. The basic system is made up of ground tissue and pith-ring. Pith-ring is the inner wall of the culm consisting of several layers of densely arranged, highly lignified cells. Be- tween the rind system and pith-ring is the ground tissue in which collateral vascular bundles are well embedded. Vascular bundles are well developed with four fibre caps, two lateral on either side of vessels and two polar, one outside the phloem and the other around the intercellular space. All of them function effectively in fixing the conductive elements in position and strengthening the ground tissue around within the culm wall. Vessels and sieve tubes are of vital importance to bamboo life, but par- tially blocked and eventually lose their conductivity due to deposition of tylosis that may cause death of the aged culms. All cells are strictly axially arranged within the internodes of culm, but become highly modified in the nodes. During intercalary growth of bamboo shoot the vascular bundles of a sheath are connected with those of the culm periphery and become abscissed off to form a sheath scar around the node after cessation of the growth. Inside the periphery, vascular bundles are variably crooked, branched or reunited in the node which becomes causatively swollen, especially in the joint of side branches. Some nodal bundles bend radially inward to pass into the dia- phragm where they are irregularly interwoven within the ground tissue, play an im- portant role in transverse conduction and provide mechanical support of the culm.更多还原