PEG胁迫对2种冰草叶片显微和超微结构的影响

Effect of polyethylene glycol (PEG) stress on the leaf blade microstructure and ultrastructure of two kinds of Agropyron cristatum

为了研究PEG渗透胁迫对冰草叶片细胞结构的影响,试验以两种抗旱性不同的冰草叶片为材料,采用石蜡切片法和电镜样品制片方法,进行叶片显微和超微结构特征的观察和比较研究,以进一步探讨干旱对冰草的显微结构和超微结构的影响。结果表明:PEG胁迫对2种冰草叶片厚度、上表皮厚度和下表皮厚度、主叶脉直径、主脉导管直径和肋状突起高度产生不同的影响;叶片细胞出现严重的变形,对叶绿体超微结构产生严重的影响,造成叶绿体被膜褶皱,基粒片层扭曲变形,叶绿体基质中的淀粉粒和质体小球明显减少。

To study the effect of polyethylene glycol （PEG） osmotic stress on the cellular structure of leaf blade of Agropyron cristatum, the leaf blades from two kinds of Agropyron cristatum with different drought resistance were used as the test material. The paraffin - section method and the method of sample preparation for electron microscope were used for the observation and comparative study of the leaf blade microstructural and ultrastructural characteristics of Agropyron cristatum to further investigate the effect of drought on the leaf blade microstructure and ultra- structure of Agropyron cristatum. The results showed that the PEG stress had different effects on the leaf blade thickness, thickness of the upper and lower epidermis, the diameter and catheter diameter of main vein, and the height of rib - like protrusion; the leaf blade cells appeared se- vere＋ deformation ; the stress had a serious effect on the uhrastructure of chloroplast, and caused the membrane envelope of chloroplast to fold, the grana lamellae turned to be distorted, and the starch granules and plastid pellet in the chloroplast stroma were reduced obviously.