解淀粉芽孢杆菌HAB-7 对18株植物病原真菌的抑制作用

HAB-7是一株分离自豇豆根际土壤、 具有较强抑菌作用的解淀粉芽孢杆菌(Bacillus amyloliquefaciens).研究HAB-7对18株植物病原真菌及其发酵液粗提蛋白对植物病原的抑制作用,并测定其对番茄种子的促生作用.采用平板对峙法测定其对18株植物病原真菌的抑制活性,以橡胶树炭疽菌为指示菌,对其发酵上清液经60%、80%硫酸铵盐析获得的抗菌粗蛋白进行测试﹔ 并将HAB-7菌液稀释成6个浓度梯度,分别用来对番茄种子进行促生测试.结果显示﹕HAB-7对18株植物病原真菌的平均抑菌率为61.03%﹔ 其发酵上清液对橡胶树炭疽病菌的抑制率为56.80%,80%硫酸铵粗提蛋白对橡胶树炭疽病菌的抑制率为38.88%﹔10-4 CFU/mL的HAB-7菌液浓度促进了番茄种子胚根的伸长,长度比CK提高67.76%.HAB-7菌株对植物病原菌有较广谱的抑菌活性,其分泌的活性物质除了活性蛋白外,可能还有其他的活性物质,低浓度的HAB-7菌液能促进植物根系生长.本研究结果为后续研究其致病机理起到重要的作用.

Analysis of Antifungal Activity of Bacillus amyloliquefaciens HAB-7 Against 18 Phytopathogens

HAB-7 is a strain of Bacillus amyloliquefaciens isolated from the rhizosphere of Vigna unguiculata and has a strong inhibitory effect on phytopathogen. The strain HAB-7 was tested against 18 phytopathogenic fungi, and the crude protein extracted from the fermented HAB-7 was also tested against the phytopathogens to observe their inhibitory activities. The tomato seeds were treated with the strain HAB-7 to observe their germination and growth. Dural culture assay was used to test the antibacterial activity of HAB-7 against 18 plant pathogens. The antifungal crude protein extracted from the supernatant of fermented HAB-7 via precipitation of 60% or 80% ammonium sulfate was tested against the fungi of rubber anthracnose caused by Colletotrichum gloeosporioides Penz. CGR-1 strain which was used as an indicator pathogen. The HAB-7 was diluted into 6 different concentrations, with which tomato seeds were treated to observe their germination and growth. The HAB-7 had an average inhibition rate of 61.03%against the 18 fungi; the supernatant of the fermented HAB-7 inhibited 56.80% of C. gloeosporioides; the crude protein of HAB-7 extracted via 80% ammonium sulfate precipitation also inhibited 38.88% of C. gloeosporioides. HAB-7 bacterial suspension at 1×104 CFU/mL improved the radical growth of the tomato seeds, 67.76% longer than the control. The HAB-7 displayed a broad-spectrum antagonistic activity, and its secreted antagonistic active substance contained antifungal protein and probably other active substances since HAB-7 bacterial liquid at a low concentration promoted plant root growth. This study plays an important role in follow-up study about its pathogenicity.