油茶内生拮抗细菌的筛选、鉴定及防效

为筛选出对油茶炭疽菌有拮抗效果的生防菌株，以油茶健康叶为对象，平板对峙法筛选，利用形态和生理生化特征以及16S rDNA基因和gyrA基因序列对菌株进行鉴定，测定其抑菌活性，并将该菌株与枯草芽胞杆菌Y13复配进行林间防效试验。结果表明，对油茶炭疽病菌拮抗作用效果较强的内生菌株为HBMC—B05；菌落为乳白色，不透明，边缘不整齐，中间有凸起；分子鉴定结果显示菌株HBMC—B05为贝莱斯芽胞杆菌Bacillus velezensis，其对果生炭疽菌Collectotrichum fructicola，抑菌率可达到81.31%，对另外3种油茶炭疽病病原菌抑菌率可达到70%以上，对其他4种致病菌也有抑制作用；复合菌剂对油茶病害的田间防治效果达到59%以上。该菌株的抑菌具有广谱性，可为油茶病害的生物防治扩充菌种资源，具有广泛的应用前景。

Screening,Identification and Antagonistic Effect of Endophytic Antagonistic Bacterial Strains from Camellia oleifera

In order to screen the antagonistic strains with antagonistic effect against Collectotrichum gloeosporioides, by using tablet confrontation method screening of strain, and excellent antagonistic strains were identified by colony morphology observation, biochemical characteristics and physiological, 16S rDNA gene Sequence analysis and gyrA gene, and the antifungal test were carried out, in addition, the control effect of BY10 combined with HBMC?B05 and Y13 was tested in the field. The result showed that the bacterium HBMC?B05 with the best antagonistic effect against Collectotrichum gloeosporioides, inhibition rate of initial screening was 70.8%, inhibition rate of rescreening was 49.6%, the colony was milky white, opaque, the edges were not neat, there were protrusions in the middle, moreover, the surface of the late stage was wrinkled and sticky, the strain was found to be gram-positive after gram-staining, by identifying molecular showed that it was identified as Bacillus velezensis. The antifungal test showed that it was the best for Colletotrichum fructicola, with a inhibitory rate of 81.31%, and to the other 3 kinds of Camellia oleifera anthracnose pathogen bacteriostatic rate can reach more than 70% and it also has good antifungal effect on the other 4 pathogenic fungi of Camellia oleifera. The field control effect of BY10 on Camellia oleifera disease was more than 59%. The strain has the bacteriostasis effect of broad spectrum, for diseases of the biological control expansion strain resource, has broad application prospects.