健株和脱病植株地上部营养器官均不存在上述症状，但两者在组织结构分化程度上有所区别。
Both healthy plant and pathogen-free plant had not these symptoms, yet there were some different in tissue differentiation of both.
感染冰核细菌溃疡病的杨树树皮的果胶质含量比健株略高。病株树皮游离脯氨酸含量在总体水平上要低于健株。
The ice nucleation activation bacterial canker disease decreased the content of mobile proline in poplar barks, while caused the content of bark pectin to increase a bit.
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