Abstract: In order to control cotton Verticillium wilt better, an endophytic bacterium with obvious resistance to Verticillium dahliae was isolated from the roots of Jimian 11. It was B.amyloliquefaciens 489-2-2 by molecular identification. In this study, 489-2-2 was used to study its'control effect and mechanism on cotton Verticillium wilt. The results showed that B.amyloliquefaciens 489-2-2 could inhibit the growth of Verticillium dahliae Vd080, resulting in abnormal mycelial morphology. The control effect of immersing cotton seeds with the fermentation broth of the strain on Verticillium wilt of cotton was 54.99%, and that of root irrigation was 60.31%. The strain produces defensive enzymes and induces strong immune response in the cotton. The strain colonizes into the root system of cotton seedlings. B.amyloliquefaciens 489-2-2 strain is a potential biocontrol strain for cotton Verticillium wilt. The results of this study provide a theoretical basis for the utilization of B.amyloliquefaciens 489-2-2 strain.

Key words: upland cotton, endophytic bacteria, plant defense enzymes, Verticillium dahlia

摘要： 为更好地防治棉花黄萎病,在冀棉11根系中分离得到一株对大丽轮枝菌抗性明显的内生细菌,经分子鉴定为解淀粉芽孢杆菌489-2-2。本试验以489-2-2为材料,研究该菌株对棉花黄萎病的防效和机理。结果表明,解淀粉芽孢杆菌489-2-2能够抑制黄萎病菌Vd080的生长,可导致Vd080菌丝形态异常。用该菌株发酵液浸泡棉花种子,对棉花黄萎病的防效为54.99%,灌根法的防效为60.31%。解淀粉芽孢杆菌489-2-2能使植株产生防御酶,诱导的免疫反应较强,且该菌株能定殖到棉花幼苗根系内部。本研究结果为解淀粉芽孢杆菌489-2-2的利用提供了理论依据。

关键词: 棉花, 内生细菌, 植物防御酶, 大丽轮枝菌