掌叶覆盆子营养器官解剖结构及其特征分析

Anatomical Structure Characters of Vegetative Organs of Rubus chingii

以江西德兴掌叶覆盆子为试材,采用光学显微镜及石蜡切片、徒手制片技术,研究掌叶覆盆子不同发育时期的根、茎、叶营养器官的解剖结构特征,探讨其结构特征与环境适应性关系。结果表明:根的次生结构中次生木质部和木栓层发达,有利于增加根系运输矿质养分和水分的能力,保护其内部组织免受高温灼烧,增强抗旱性。根的次生结构中产生大量木薄壁细胞、木射线和韧皮射线、韧皮部薄壁细胞,成为营养物质贮存的场所,为根上不定芽的发生、发育提供充足养分奠定了基础,与其每年萌发新枝、2年生枝结果然后死亡的生长特性相适应;茎的次生结构中导管分子口径大,数量多,茎中央髓部大,具有明显旱生形态特征;叶为典型异面叶;上表皮细胞整齐,排列紧密,气孔少见;下表皮气孔器密度较大;栅栏组织和海绵组织发达,表现出阳生叶的结构。

To better understand the environmental adaptability of Rubus chingii from Dexing,Jiangxi,the anatomical characters of its vegetative organs were studied with optical microscope,paraffin section,freehand section.The results showed that the secondary structure of the roots with developed secondary xylem and developed phellem layer were observed.The developed secondary xylem was helpful for adding the roots＇ ability to transport mineral nutrients and water.And the developed phellem layer could protect roots internal organization from heat injury to increase roots＇ drought tolerance.It was observed that there were lots of xylem parenchyma cells,wood rays,phloem rays and phloem parenchyma cells in the secondary structure of the roots where reserving nutrition substance.Vessel element was not only big diameter but also multiple quantity in the secondary structures of the stem;the developed pith was in the center of stem.Leaf was typical bifacial,the upper epidermal cells were neatly arranged closer;rare stomata were observed on upper epidermis.More stomata distributes under epidermal.There was developed palisade tissue and spongy tissue in leaf.The structure of the raspberry leaf showed the sun leaves.