槲寄生内生真菌在槲寄生寄生过程中的作用

Study function of endophytic fungus in parasitism process of mistleto

目的:研究槲寄生内生真菌在槲寄生寄生过程中的作用。方法:将槲寄生8个不同部位的组织进行外植体培养,分离纯化其内生真菌,利用CMC平板培养和DNS法筛选出具有较高纤维素酶活性的菌株;将槲寄生寄生的膨大部位进行组织切片,染色观察其内生真菌的组织分布。结果:槲寄生体内分布着丰富的真菌菌丝;从槲寄生各组织部位共分离出83株内生真菌;初步筛选得到38株可降解纤维素的菌株,19株降解纤维素能力较强,其中10株分离自槲寄生寄生的膨大部位。结论:内生真菌分泌纤维素酶可降解枫杨树的细胞壁及细胞间隙组织,协助槲寄生的吸器穿透枫杨树组织,帮助槲寄生在枫杨树上寄生。

Objective： To research the function of endophytes of mistletoe in parasitism process of mistletoe in Pterocarya stenoptera. Method： Endophytes from eight different parts of the mistletoe were separated by explant culture, and further screened by different CMC plates culture and DNS method to get cellulase high productive strains. The distribution of the endophytic fungus parasitized in mistletoe were prepared and stained to demonstrate by histological section of the intumescentia part of the P. stenoptera. Resuit： The histological section indicated that aboundent of hyphasma were distributed around the haustorium of the mistletoe. Eighty three strains of endophytic fungus were separated, 38 of them were able to degrade cellulose, 19 strains showed high cellulase activity and 10 of which were separated from the parasitic position. Conclusion： Endophytic fungus of mistletoe can secrete cellulase and assist the haustorium of mistletoe to breakthrough the cell walls as well as intercellular space tissues of the P. stenoptera, thus, the endophytic fungus plays an important role in the parasitism process of mistleto in P. stenoptera.