苏铁珊瑚根结构观察及其内生放线菌分离

Structural observations of Cycas revolute coralloid root and disassociation of endophytic actinomycetes

苏铁类是现存最原始的裸子植物类群,被认为是活化石。为了探究清苏铁珊瑚根的结构和内生放线菌的多样性,本研究采用石蜡切片法对苏铁珊瑚根进行显微结构观察,用改良的TWYE(M1)、高氏1号(M2)和甘油—天冬酰胺(M3)培养基对珊瑚根的内生放线菌进行分离,并通过16S rRNA系列分析鉴定其种属。结果表明:苏铁珊瑚根由周皮、外部皮层、藻胞层、内部皮层和维管柱组成;外部皮层和内部皮层细胞在横切面上呈圆形,而且在有的细胞中能看到被染成暗红色的菌丝团的存在;利用以上三种培养基从苏铁珊瑚根中共分离到了13株放线菌,隶属于链霉菌属和拟诺卡氏菌属。

Cycad is the most primitive extant gymnosperms, which is considered to be living fossil. In order to explore the structure and the endoPhytes actinomycetes of cycad coralloid root, the paraffin section was used to do the observation on microstructure; TWYE（M1 ）, Gao one （M2） and Glycerin - asparagine mediums were used to seprate the endophytic actinomycetes in the coralloid roots and through 16S rRNA sequence analysis, the Actinomycetes were identified. The results indicate that the periderm, outer cortex, cyanobacterial zone, internal cortex and vascular cylinder consisted of the cycad coralloid root; the cells of the external and internal cortex presented to be a circular form on the cross section, and pelotons that were stained to be red existed in some cells of them. 13 strains of actioumycetes were separated from the cycad coralloid root through the above three mediums, and they belong to streptomyces and nocardiopsis.