一株茶树根际细菌的鉴定与生防效果研究

炭疽病是茶树的重要病害之一,对茶叶的生长和产量造成严重的危害.目前该病的防治主要依靠化学药剂,开发生物防治产品是推广茶树绿色防控技术主要措施之一.用生理生化特征分析和分子生物学技术鉴定一株茶树根际生防菌JT68,评估其对茶炭疽病菌的抑菌效果以及菌液对菌丝生长和孢子萌发的影响.用对扣法检测该菌株的挥发性有机物对茶炭疽菌的...

Identification of a Tea Rhizosphere Bacterium and its Biocontrol of Tea Anthracnose Disease

Tea anthracnose (Colletotrichum gloeosporioides) is one of the most important fungal diseases of Camellia sinensis worldwide, which causes serious damage to tea growth and production. The control of tea anthracnose is mainly dependent on chemical fungicides. To promote green prevention and control in tea plantation, development of biocontrol agents is critically important. A bacterium named JT68 isolated from tea rhizosphere was identified based on physiological and biochemical analysis and PCR. The inhibition effects of fermented broth JT68 on confrontation culture, mycelia growth and spores germination were determined. The effect of volatile organic compounds (VOCs) of JT68 was tested and the components were identified by GC-MS. The control effect of JT68 was determined using detached leaf method. The results of this study shows that the strain JT68 was identified as Bacillus amyloliquefaciens. Plate confrontation shows that the inhibition rate of fermentation broth of JT68 against C. gloeosporioides was 80.94%. Co-culture shows that the inhibition rate of spore germination of C. gloeosporioides was 99.18%, and the mycelia of pathogen shrank and formed chlamydospores. The VOCs of JT68 could inhibit 50.73% mycelia growth of C. gloeosporioides. Ketones such as 2-Nonanone and 2-Undecanone were revealed as major components in VOC through GC-MS analysis. Leaf detached inoculation shows that the relative inhibition rates of the original fermentation broth, 10-fold, and 100-fold dilutions were 83.20%, 79.70% and 72.66%, respectively. Furthermore, our study found that JT68 strongly inhibited the growth of Magnaporthe grisea, Fusarium oxysporum, C. capsici, C. higginsianum, Verticillium dahlia and Sclerotium rolfsii with the inhibition rates of 70.0%- 93.2%. Our study provided a biocontrol agent B. amyloliquefaciens from tea rhizosphere, which showed superior biocontrol effect against C. gloeosporioides. This strain had been applied to develop biofertilizer and widely used in the field, which would reduce the use of chemical fungicide and implement prevention and control in tea plantation.