外来植物黄顶菊营养器官解剖特征及其生态适应性

Anatomical characters of vegetative organs and ecological adaptability of new alien species Flaveria bidentis

采用扫描电镜和光学显微镜对外来植物黄顶菊营养器官的解剖结构研究。结果表明:黄顶菊叶片表皮具较厚的角质层、下陷气孔,叶片为等面叶、全栅型,叶肉细胞环绕维管束鞘细胞紧密排列,是典型C4植物的Kranz花环结构;茎中厚角组织和维管组织发达,根中还存在通气组织;根、茎、叶中均存在分泌结构。综合光照、温度、土壤pH、有机质、含盐量及伴生种等生态因子分析表明,黄顶菊喜光、喜高温,耐受干旱、盐碱及贫瘠土壤,可与一些耐干旱耐盐碱较强的植物共生。黄顶菊营养器官特别是叶片的解剖特征体现的生态适应性可能与其耐受恶劣生境的能力之间存在一定的相关性,可能是导致黄顶菊具有较强入侵性的原因之一。

To better understand the ecological adaptability of alien species Flaveria bidentis, the anatomical characters of its vegetative organs were studied with scanning electron microscope and optical microscope. F. bidentis leaf was of isobilateral type, and had thicker epidermis cell wall and cuticle, obvious eryptopores, and highly developed palisade tissue, with typical C4-plant Kranz anatomy. The collenchymas and vascular tissue in stem and the aerenchyma in root were well developed. Secretory structure was found in all vegetative organs. According to the analyses of soil physical and chemical properties and relevant ecological factors, F. bidentis preferred to live under strong light and high temperature conditions, and exhibited strong tolerance against drought, saline/alkaline, and poor nutrients, being able to coexist with some drought- and salt-tolerant plants. It was suggested that the strong adaptability of F. bidentis to harsh environment had definite relations to the anatomical characters of its vegetative organs, being one of the causative factors responsible for the invasiveness of F. bidentis.