BS-Z15代谢产物防治棉花黄萎病的作用及对棉花生长的影响

Effect of BS-Z15 Metabolites on Cotton Verticillium wilt Prevention and Cotton Growth

BS-Z15是从棉花根际土壤中分离筛选出的一株高效拮抗大丽轮枝菌的芽孢杆菌。该菌株通过发酵能产生胞外分泌型次生代谢产物,且该产物具有良好的稳定性及高效的拮抗大丽轮枝菌活性,是良好的防治棉花黄萎病的候选活性物质。本研究以BS-Z15菌株抗大丽轮枝菌次生代谢产物为研究对象,研究其对盆栽棉花黄萎病的防治作用,通过荧光定量法分析了该活性物质对病原菌在棉花体内积累的影响,并进一步探讨该活性物质对棉花生长和光合特性的影响,以期为开发利用BS-Z15次生代谢活性物质作为棉花黄萎病的防治手段提供实验依据。结果表明,较伤根感病对照组,采用浓度为0.33 mg/m L BS-Z15抗大丽轮枝菌活性物质进行防治的伤根感病防治组,棉花黄萎病发病率显著降低,病症明显缓解。侵染一周后,未出现严重的黄叶掉叶现象,荧光定量结果显示防治组棉株体内病原菌的表达量也显著低于对照组,与非侵染感病的阴性对照组相比,则无显著性差异。在使用浓度为0.33 mg/mL抗大丽轮枝菌活性物质处理棉花植株三周后,对棉花植株的光合特性指数无显著性影响。另外,本研究发现棉花株高、根长低于对照组,推测该浓度的抗大丽轮枝菌活性物质可能对棉花的生长有一定影响。综上所述,本研究表明BS-Z15抗大丽轮枝菌活性物质可有效抑制大丽轮枝菌侵染棉花植株,降低棉花黄萎病发病率。

BS-Z15 is a kind of bacillus strain which is isolated from the cotton rhizosphere soil.It is effectively antagonize Verticillium dahlia.This strain could produce and secrete metabolites which showed good stability and antagonistic activity of the bacillus,and might be a potential candidate for cotton Verticillium wilt prevention.In our study,we assessed the prevention function of active substance produced by BS-Z15 against Verticillium wilt of cotton in pot experiment.Real-time quantitative PCR was employed to analysis the accumulation of Verticillium dahlia within the cotton.Besides,we further investigated the effect of active substance on the plant growth and photosynthetic characteristics of cotton.Aiming to provide experimental supports for developing antifungal active substance as a potential method for cotton Verticillium wilt prevention.Our data indicated that compared with Verticillium wilt infection alone group,the cotton treated with active substance(0.33 mg/mL)showed lower morbidity,less severity,less leaf abscission and reduced pathogenic bacteria accumulation after treating for one week.Besides,after treatment for three weeks,the photosynthesis characteristics between groups showed no significantly difference.The plant height,and root length was decreased in the active substance treatment group,suggested that such a high concentration(0.33 mg/mL)of active substances may have a mild impact on the growth of cotton.Together,this research showed that the active substance secreted by BS-Z15 could efficiently prevention the cotton against Verticillium wilt infection and reduce morbidity.The mechanism how the active substance influence the growth of cotton needs further investigation.