烟草青枯病生防菌的筛选及其田间防效评价

为筛选出对烟草青枯病有效防治的生防菌,通过稀释涂布法从烟株根际土壤分离到一株具有明显拮抗作用的菌株69-1,经16S rDNA鉴定该菌株为壮观链霉菌(Streptomyces spectabilis),并用该菌株进行烟草青枯病田间防治试验。结果表明,与对照相比,经菌株69-1处理烟株茎围、有效叶片数、最大叶宽、最大叶长、上中下部烟叶单叶干重、最大叶面积、产量均显著增加,且对烟草青枯病的相对防效达60.42%,同时对不同处理组的初烤烟叶进行化学成分的检测分析,发现菌株69-1处理相对于对照组烟叶品质更佳。该菌株菌剂处理不仅可以提高烟株对烟草青枯病的防效,而且还提高烟叶品质和产量,可为烟草青枯病生物防治提供一定参考。

Screening of Biocontrol Bacteria Against Tobacco Bacterial Wilt and Evaluation of the Field Control Effect

To screen out the biocontrol bacteria that can effectively control tobacco bacterial wilt, a strain 69-1 with obvious antagonism was isolated from the tobacco rhizosphere soil by dilution coating method, and the strain was identified as Streptomyces spectabilis and used for field control experiments of tobacco bacterial wilt. The results showed that compared with the control, the stem circumference, effective leaf number, maximum leaf width, maximum leaf length, single leaf dry weight, maximum leaf area, and yield of tobacco leaves treated with strain 69-1 increased significantly. The relative control effect on tobacco bacterial wilt reached 60.42%. At the same time, the chemical composition of the flue-cured tobacco leaves of different treatment groups was analyzed and found that the tobacco quality under strain 69-1 treatment was better than that of control. The bacterial agent treatment of the strain can not only enhance the control effect of tobacco plants against tobacco bacterial wilt, but also improve the quality and yield of tobacco leaves, and the study can provide a certain reference for the biological control of tobacco bacterial wilt.