杨树溃疡病菌毒素对杨树树皮愈伤组织超微结构的影响

用２种浓度的杨树溃疡病病菌毒素处理具有不同抗生的杨树愈僵组织，引起了显著的超微结构变化。其变化包括：细胞壁变形消解，中胶层分解；质壁分离，质膜破裂，线粒体局部破裂、分解成颗粒甚至空胞化；细胞核在处理的后期核膜破裂，核仁亦部分分解，损害发生得最早、最严重的是细胞膜、杨树未处理的愈伤组织具有健康组织细胞所具有的完整结构。经过毒素处理，抗病品种比感病品种膜系列受因轻，对细胞损伤高浓度毒素处理比低度的要大

Ultrastructure of Calli Cells of Poplar Exposed to Toxin Produced by Dothiorella gregaria

Calli of poplar susceptible and resistant to poplar blister canker disease were exposed to the toxin produced by a pathogenic isolate of Dothiorella gregaria at two concentrations. All the cells exposed to toxin showed a series of sub-cellular ultra-structural changes such as distorted and collapsed cell walls and plasmolysis;ruptured plasma membranes;disrupted outer-membranes of mitochondria, some of them even broke down and became granular or hollowed;membrane of nucleolus dilated and part of it decomposed. Cells from the susceptible poplar displayed mitochondria and cytoplasmic disruption. Plasma membranes appear to be the first organs to be attacked seriously. Cells from the untreated tissue exhibited typical internal composition associated with healthy, actively growing cells. The differences between the susceptible and resistant poplar, which were exposed to high level and low level of toxin concentration are that: at the same time after exposed to toxin, the ultrastructure of susceptible poplar were more serious disturbed than that of the resistant one, and the same influences showed in the high level of toxin concentration.