竹类植物花序建成及花序类型修正

【目的】竹类植物的花序在竹类植物分类及繁殖中有非常重要的地位,其形态特征也是竹类植物分类的依据之一。然而由于竹类植物特殊的开花特性,目前对竹类植物花芽分化及花序建成的研究资料较少,此次研究为更好地明晰竹类植物的花序类型及形成过程提供依据。【方法】采用石蜡切片和形态观察相结合的方法,以苦竹属(Pleioblastus)的翠竹、东笆竹属(Sasaella)的黄条金刚竹以及箣竹属(Bambusa)的‘霞早’绿竹为材料,对其花序建成过程进行了观察。【结果】尽管3个竹种花序外在形态表现多样,但其花序类型都为混合花序,即花序主轴小穗发育为有限花序,而组成各小穗的小花发育为无限花序。同一个花序中顶部小穗最先发育,然后由顶部向基部依次发育出侧生小穗原基,为有限花序; 而同一小穗上不同部位小花的发育进程则按基部到顶部的顺序依次进行。【结论】综合小穗和小花的发育过程,将原属于有限花序(真花序)的黄条金刚竹和翠竹以及原属于无限花序(假花序)的‘霞早’绿竹的花序类型进行统一,将竹类植物花序定义为混合花序。

Research on inflorescence establishment and revision of inflorescence type in bamboo plants

【Objective】 The inflorescence plays an important role in taxonomy and propagation in bamboo plants. Its morphological characteristic is one of the bases for bamboo classification. However, the specialized flowering characteristics, long vegetative period and short reproductive period in bamboo have greatly limited research on its reproductive biology. At present, there is little research data available on bamboo flower bud differentiation and inflorescence types. The study therefore aimed to clarify types of bamboo inflorescence and the development processes. 【Method】 We used Bambusa oldhamii ‘Xia Zao’ ZSX, Sasaella kongosanensis ‘Aureostriatus’ and Pleioblastus pygmaeus as our samples in order to study the establishment process of the inflorescence in detail, employing paraffin sections and morphological observation as our methodology. 【Result】 These three bamboo varieties all have mixed inflorescences, with a varied external inflorescence morphology: the spikelet development on the inflorescence spindle was a definite inflorescence, while the floret development on the spikelet was indefinite. The top spikelet first developed on one inflorescence, followed by the second spikelet primordia at the base of the top spikelet, and so on, in a similar fashion, while the floret on a different part of the same spikelet developed from the base to the top. 【Conclusion】 Based on the spikelet and floret development, we combined the formerly determinate inflorescences(S. kongosanensis ‘Aureostriatus’ and P. pygmaeus)and the formerly indeterminate inflorescence(B. oldhamii ‘Xia Zao’ ZSX)into a single type of mixed inflorescence.