卷丹珠芽萌发的组织学观察

以卷丹(Lilium laneifolium)珠芽为试材，采用野外调查法、石蜡切片法、徒手切片法、离析法，观察珠芽各部分形态和结构，用分光光度法测定各片鳞叶的花青素和光合色素含量，为其珠芽繁殖生物学研究提供资料。结果表明，珠芽由鳞叶、鳞茎和不定根构成，鳞叶外表皮细胞具有发达的角质层，外表皮内侧1～2层叶肉细胞含有花青素；叶肉细胞含绿色造粉体，第1～3片鳞叶基部的绿色造粉体向不定根伸长方向集中分布，鳞叶色素含量由外至内逐渐降低；鳞叶维管束为外韧维管束。鳞茎主要由皮层和维管柱构成，鳞茎上端包括顶端分生组织和芽鞘，在下端细胞部分发生程序性死亡，但未发现类似叶片脱落时叶柄基部出现的离层结构。不定根起源于第2片鳞叶基部环生的鳞茎皮层细胞，不定根与周围鳞叶组织分离。在珠芽萌发过程中鳞叶的物质供给出现分化现象。

Histological Observation on the Germination of Lilium laneifolium Bulbil

To provide data for the in-depth study of bulbil propagation biology of Lilium laneifolium, taking the bulbils as experimental materials, the morphology and structure of each part of bulbils were observed by field investigation, paraffin section, freehand section, and segregation process, and the contents of anthocyanin and photosynthetic pigments were measured among each scale leaf by spectrophotometry. Bulbils were composed of scale leaves, bulb and adventitious root, in which outer epidermis cells had developed cuticle; 1–2 layers of mesophyll cells inside the outer epidermis contained anthocyanins, all mesophyll cells contained chloroamyloplasts; the chloroamyloplasts at the base of the 1st–3rd scale leaves were concentrated in the direction of adventitious root elongation, the pigment contents of scale leaves gradually decreased from outside to inside, and scale leaf bundles belonged to collateral vascular bundles. The bulb was mainly composed of cortex and vascular column, in which the upper end of the bulb included the apical meristem and apical bud sheath, while at the lower end of the bulb, some cells underwent programmed death, and yet no abscission layer similar to that at the base of petiole during leaf abscission was found. The adventitious root originated from the cortical cells of the bulb part around which the base of the second scale leaf was borne, and the adventitious root was separated from the surrounding scale leaf tissue. During the process of bulbil germination, the material supply of scale leaf appeared differentiation phenomenon. These results provided a structural basis for the study on biological mechanism of the bulbil propagation of L. laneifolium.