柿疯病研究Ⅱ.病原

 从柿疯病株的1-2年生枝条或根的输导组织中,抽取组织液并离心富集制备样品,经磷钨酸钠负染,和Epon812树脂常规包埋超薄切片,在电镜下检查很多多型性原核细胞,大小不一,长580-1600nm,宽510-1060nm,胞壁呈山脊状波纹,厚约25nm,无鞭毛而周身分布微小疣突,按其形状大小和亚显微结构特征确定为难养细菌(Fostidious bacteria)而不同于一般植物病原细菌,健株制备的样品中未检查到任何微生物。这个结果与前文报道青霉素可抑制和缓解柿疯病症状表现的结果是一致的[1],检查到的这种难养细菌认为是柿疯病的病原物。
前已证明,柿疯病可以嫁接传病,并对该病的症状作了系统的观察和描述[1],本文报道柿疯病病原的研究结果。

STUDIES OF PERSIMMON PROLIFERATION DISEASE II. ETIOLOGY

The preparations were separated and concentrated with differential centrifugation from vascular tissue sap which had been pumpted from twig or root segments of proliferation diseased and healthy persimmon.They were obseved by means of negative staining and ultrathin section with electron microscopy.Nu merous pleomorphic procaryotic cells were found exclusively in the preparations made from diseased plants.They are of varying sizes, usually 580-1600 nm in length and 510-1060 nm in width.The cell wall looks ripply externally, about 25 nm in thickness.No flagella but several prosthecae occur on the surface of the cells.The pleomorphic procaryote in question with all those cytological characteristics is distinct obviously from ordinary bacteria and it was identified as a sort of fastidious bacteria cteria.There is no microbe whatsoever to be found within the samples made from PPD-free pesimmon.This result is consistent with that of formal researches which elusidated the symptoms of PPD could be depressed by treatment with enicillin.Therefore, the fastidious bacterium seems to be the pathogen of PPD.