3株棉花黄萎病菌拮抗菌株生防、促生效果研究

Study on Biocontrol and Growth Promotion Effects of 3 Antibacterial Strains against Verticillium dahliae in Cotton

为测试对棉花黄萎病菌(Verticillium dahliae)具有拮抗作用的3株菌(kx-4、kf-43-1、kf-5-1)对棉籽发芽的影响及在盆栽和大田试验中拮抗、促棉花生长的作用。利用发酵液法对3株拮抗菌抑菌活性、促芽效果进行测定;通过切根蘸菌法、灌根接种法分别测定了拮抗菌对棉花黄萎病的盆栽、大田防病和促生效果。结果表明,3株拮抗菌无菌发酵滤液,对棉花黄萎病菌菌丝的抑制率为65.49%~87.41%,与对照比棉籽发芽率提高2.86%~14.29%;3株拮抗菌在盆栽、大田试验中防效均显著高于对照,对棉株均有不同程度的促生作用。其中拮抗菌株kf-43-1株防效最好,盆栽防效最高可达80.27%;在大田接拮抗菌20 d后防效为53.95%;kx-4株促生效果最好,发酵液灌根处理的棉株株高、下胚轴直径、始节高、铃数、有效铃数、衣分的测量数值均显著高于对照及其余2株拮抗菌发酵液灌根处理的棉株。

In order to determine whether the three strains(kx-4,kf-43-1 and kf-5-1)with antagonistic effect on cotton seed germination of Verticillium dahliae have any effect on cotton seed germination,and whether they have stable antagonistic characteristics and promote the growth of cotton in pots and field experiments.The following experiments were carried out in this study:3 strains were tested by fermentation broth method for their antibacterial activity and bud promotion effect.The effects of antagonistic bacteria against Verticillium wilt of cotton in pot and field were measured by root cutting and root grafting.The results showed that the inhibition rate of three strains of antagonistic fermentation broth on mycelium of Verticillium wilt of cotton was 65.49%-87.41%,which increased the germination rate of cotton seeds by 2.86%-14.29%compared the contol.The control effect of the three antagonistic bacteria was significantly higher than that of the control group in pots and field experiments.Among them,antagonistic strain kf-43-1 had the best control effect,and potted control effect was up to 80.27%.The anti-bacterial effect was 53.95%after 20 days in the field.kx-4 had the best growth promotion effect,and the measured values of plant height,hypocotyl diameter,starting height,boll number,effective boll number and coat fraction of the cotton inoculated with its fermentation broth were significantly higher than those of the control with water and those inoculated with the other two antagonistic cotton strains.