细叶百合鳞茎花芽分化过程观察

Morphological and histological observation of flower bud differentiation in the bulbs of Lilium pumilum

以细叶百合（Lilium pumilum）鳞茎为试材,利用石蜡切片和扫描电子显微技术,对细叶百合鳞茎花芽分化全过程进行形态学和组织细胞学观察,研究细叶百合鳞茎在自然越冬状态下花芽的发生、发育进程。结果表明,细叶百合鳞茎芽顶端生长点9月中旬开始由营养茎端向生殖茎端转变,11月中旬封冻前,芽顶端生长点最下面1～2个小花原基已完成花被原基的分化,翌年春季解冻后,继续进行花芽分化,至5月中旬前,整个花序分化完成。整个花序分化历时8个月左右,形成4～7个花蕾,并可将百合花芽分化划分为未分化期、分化初期、小花原基分化期、花被原基分化期、雄蕊和雌蕊原基分化期、整个花序形成期6个时期。

Anatomic observations with the paraffin sections and scanning electron microscope （SEM） were explored in the terminal bud of Lilium pumilum during flower bud differentiation period to investigate the flower bud development process of L. pumilum bulbs which had come through winter without any special protection. The results showed that morphological characteristics of the stem apex growing point changed from growing cone to reproductive cone in the middle of September. In mid-November, the bottom of inflorescence primordium of the one or two foret primordial had completed the differentiation of perianth primordium, and flower bud continued to differentiate in the following spring. Then the whole inflores- cence finished the differentiation before mid-May. The differentiation of inflorescence lasted 8 months, and formed 4-7 flower buds. The flower bud differentiation of L. pumilum could be divided into six stages, which were undifferentiation phase, initial differentiation phase, foret primordial differentiation phase, perianth primordium differentiation phase, stamens primordium and pistil primordium differentiation phase and the whole inflorescence formation phase, respectively.