摘要
以营养器官的部分性状,对旱生和水生空心莲子草不同器官的结构和物质进行了研究,并据此对2种生境空心莲子草形态结构变化进行了比较。对比研究结果表明,二者营养器官因环境适应而发生了较大变化,其中叶宽、叶片角质层厚度、孔下室面积、气孔数量与分布表现显著差异,旱生者具有长的表皮毛,而水生的则完全没有。茎中节间长度、髓腔直径、髓射线宽度和输导组织的类型、数量及比例在不同生境的茎和不同生长型的茎中均表现出显著的变化。旱生匍匐茎和根状茎节上具宿根,含大量贮藏物质,并生有多量的不定芽,具备成为独立散布体的物质和结构基础,而水生茎则因适应吸收需要,产生大量不定根。空心莲子草花粉败育率高(约80%),可能是其较低结实率的原因之一。空心莲子草在较低的有性生殖率下如何完成远距离扩布值得进一步探讨,此点在杂草防治中可能具有一定的意义。
The morphogenesis and anatomical changes of Alternathera philoxeroides in different habitats(xeric and aquatic environments),were chosen as characteristics to appraise this weed under heterogeneous habitats.There were significant differences between the vegetative organs from two ecotype due to adaptation to heterogeneous ecotypes.The distribution and quantity of stomata between the two leaves showed a notable distinction;leaves of the xeric form had long epidermal hairs on both upper and lower epidermis,while the aquatic form had none on either.There were also significant differences as to type,quantity and proportion of conducting tissue in stems from different habitats and different ecobiomorphisms.The perennial roots from the xeric's stolon and rhizome had many adventitious buds which contained a high content of stored substances,and had the material and structural basis to be independent diasporas.In contrast,the aquatic only had numerous fibrous roots to meet absorption needs.The pollens of A.philoxeroides had a high abortion percentage(approximately 80%),which may be one reason for its low seed setting rate,but how it achieves invasion over long distances with such a low sexual reproduction rate deserves to be discussed,because of its significance in weed control.
出处
《草业学报》
CSCD
北大核心
2011年第4期143-152,共10页
Acta Prataculturae Sinica
基金
国家自然科学基金资助项目(39730100)
国家基金资助项目(30070640)
安徽省教育厅自然科学基金资助项目(200KJ165B
KJ2008B07ZC)
安徽科技学院专项基金资助项目(ZRC200436)资助
关键词
空心莲子草
形态解剖结构
物质基础
异质生境
生态适应
Alternathera philoxeroides
morphological and morphological structure
material basis
heterogeneous habitas
ecological adaptability