虉草营养器官解剖结构与抗旱耐涝性及利用之间的关系

Anatomical Structure of Vegetative Organs of Phalaris arundinacea L.in Relation to Drought Resistance,Waterlogging Resistance and Use Value

为了从显微结构上进一步探讨虉草(Phalaris arundinacea L.)的抗旱耐涝性及与利用的关系,于2011年采用常规石蜡切片技术,对其根、茎叶3种营养器官进行解剖观察。结果表明,虉草根的结构自外而内依次为表皮、皮层、维管束鞘、初生韧皮部和初生木质部;茎由表皮、基本组织和维管束构成;叶片内部结构可分为表皮、叶肉和叶脉3部分。根皮层大的细胞间隙和气腔,初生木质部的后生大导管和茎基本组织解体形成的髓腔都是虉草良好的通气组织,是其耐水淹的主要显微特征。茎、叶片角质化的表皮和叶表皮所含的丰富泡状细胞组是虉草具有抗旱性的主要解剖结构特征。叶肉细胞排列紧密且只有少量气孔分布于叶片下表皮,这样的结构可减少蒸腾;叶肉细胞富含叶绿体,增强光合作用,获得更多的同化产物,确保了植株在干旱条件下也有足够的光合产物来维持正常的生理活动。茎、叶维管束部分大量的木纤维起到支撑作用。虉草根的皮层和维管柱部分、茎的基本组织和维管束部分、叶的叶脉部分都含有大面积的厚壁细胞,厚壁细胞中含有丰富的粗纤维和木质素。丰富的粗纤维、木质素等成分则是虉草能成为新能源燃料植物的必备条件。

Paraffin wax section technique was applied for microscopic observation of vegetative organs （root, stem and leaf） , to study the drought and waterlogging resistance and use value of Phalaris arundinacea L. The results showed that the structure of the root, from outside to inside, was as follows： epidermis, cortex, bundle sheath, primary phloem and primary xylem. Stem was composed of epidermis, ground tissues and vascular bundles. Leaf was composed of epidermis, mesophyll ceils and veins. Good ventilation organization visible in root cortex cell gaps and air cavity, primary xylem epigenetic catheter and medullary cavity were the main microscopic characteristics of waterlogging resistance. The hornificated epidermis of stem and leaves and its abundant bulliform cell groups were the main anatomical structure reasons for drought resistance. Tightly arranged mesophyll ceils which contained large amounts of chloroplasts reduced transpiration and enhanced photosynthesis to ensure plant＇ s photosynthesis even under drought conditions. A large numbers of wood fibers in vascular bundles of stem and leaves which support the plant, were major microscopic characteristics of trampling resistance. There were large areas of sclerenchyma cells in root epidermis and vascular tissues. Stem ground tissues and vascular bundles and leaves veins which were abundant in lignin and cellulose are the necessary characteristics of a new bioenergy plant.