金鱼草叶序变化的形态解剖学研究

Morphological and anatomical characteristics of phyllotaxy of Antirrhinum majus

采用石蜡切片法,对金鱼草在生长发育过程中主茎上不同节位的顶芽作了形态和解剖方面的观察研究。结果显示,金鱼草主茎第1～6节位生长锥形成对生叶原基,展开后为交互对生叶序,叶片呈卵形至椭圆形;第7节位,24.4%的生长锥产生对生叶原基,形成对生叶序,75.6%的生长锥单侧产生互生叶原基,形成互生叶序;第8节位,84.0%的生长锥产生互生叶原基,形成互生叶序;至第9节位起生长锥全为单侧产生互生叶原基,形成互生叶序,叶片变成狭长形的披针形。表明金鱼草主茎第7～8节位是其叶序由对生向互生转变的节位。自第13节位后主茎顶芽顶端生长停止,变为花芽而开花,最迟至第17节位止。对生叶序状态下未见有开花者。在主茎顶芽变为花芽后,侧芽也相继活动,形成花芽,陆续开花。

In this paper, paraffin method has been used to make the morphological and anatomical observation of terminal buds on different nodes ofAntirrhinum majus caulis during development. The result shows that the growth cones located from the 1-6th nodes of the caulis of Antirrhinum majus will develop to opposite leaf primordiums and become decussate opposite phyllotaxis. The shape of the leaves varies from ovate to oval. 24.4% of growth cones located on the 7th node will develop to opposite leaf primordiums and become opposite phyllotaxis, The other 75.6% will develop to alternate leaf primordiums on one side and become alternate phyllotaxis. On the 8th node, 84.0% of growth cones will develop to alternate leafprimordiums and become alternate phyllotaxis. From the 9th node, all of the growth cones will develop to alternate leaf primordium on one side and be come alternate phyllotaxis. The leaf will turn to long and narrow lanceolate shape. This means the 7-8th nodes of Antirrhinum majus caulis are the nodes where the phyllotaxis changes from opposite to alternate. From 13th node （no later than 17th）, the terminal bud of caulis may stop apical growth and becomes flower bud. There is no flower bud in opposite phyllotaxis. After the terminal bud of caulis turning to flower bud, the lateral branches will also develop as the caulis. The lateral buds will turn to flower buds and blossom one after another.