生理性缺铁对库尔勒香梨叶片解剖结构的影响

Effects of Physiological Iron Deficiency on Leaf Anatomical Structure of Kuerle Fragrant Pear(Pyrus bretschneideri Rehd)

为了解生理性缺铁对库尔勒香梨叶片解剖结构的影响,利用透射电镜和石蜡切片法,比较研究了库尔勒香梨在缺铁状态下不同发育期的叶片解剖结构。结果表明,与正常叶相比,缺铁黄化叶片厚度、叶片栅栏组织厚度均极显著降低(P<0.01),叶片上表皮与下表皮厚度均极显著增加(P<0.01)。缺铁黄化叶片维管束细胞排列凌乱,导管严重变形,口径变小,生长后期表现更为突出。黄化叶片叶肉栅栏细胞中叶绿体变形且明显变小,片层系统不能堆垛形成基粒而使基粒片层大部分消失;海绵组织细胞排列松散,细胞内结构解体,甚至整个细胞空泡化。研究认为,香梨叶片外部表现黄化症状是由叶片内部及组织结构变化控制的,对比缺铁导致的标志性显微结构异常以及亚显微结构中特定细胞器的损伤,可以初步区分不同缺素或多重缺素对香梨叶片解剖结构造成的影响。

The obj ective of the study was to observe the effect of physiological iron deficiency on leaf anaG tomical structure of Kuerle Fragrant Pear by using transmission electron microscopy （TEM）and light mircroscopy.The anatomical structure of chlorotic and helathy leaves of Kuerle Fragrant Pear was comparG atively investigated at different developmental stages by using transmission electron microscopy （TEM） and light microscopy.The results indicated that leaf thickness of iron deficiency,palisade tissue thickness and cell tense ration of chlorotic leaves were significantly lower than those of healthy leaves.The thickness of upper and lower epidermis was remarkably thicker than those of healthy leaves.The arrangement of the cells in vascular bundles was in disorder.The vessels were distorted seriously and the caliber of the vessel became smaller.The symptoms were more prominent at later growth stage.The chloroplasts of chlorotic leaf distorted and their sizes became smaller obviously.IronGdeficiency influenced the formation of grana in a chloroplast.The arrangement of the cells in spongy tissue was loosen,the organelles of cells in the chloG rotic leaves was broken ,even cavity appeared in the whole cell .The study believed that upper chlorotic symptom of Kuerle Fragrant Pear leaves was controlled by the changes of leaf inside and organizational structure.The marker microscopic structure mutation and damage of special cell in subGmicroscopic strucG ture produced by iron deficiency can distinguish the influence of single nutrient deficiency or multiple nutriG ent deficiency on the anatomical strurture of pear leaf.