解淀粉芽孢杆菌在葡萄叶片上的定殖能力研究

Studies on Colonization of Bacillus amyloliquefaciens on Grape Leaves

为探究解淀粉芽孢杆菌在葡萄叶片上的定殖能力,本研究先后采用利福平和链霉素对解淀粉芽孢杆菌N24进行双抗诱导,获得了菌落特征与野生菌相同且抗药性稳定的双抗菌株（抗利福平320μg/mL、抗链霉素150μg/mL）。此双抗菌株在葡萄叶片上的定殖试验结果表明：浓度为1×10^4cfu/mL和1×10^6cfu/mL的菌液喷施叶面后,5-10 d菌量快速增加,10 d达到最高峰,此时其定殖和繁殖能力最强,尤其是起始菌液浓度为1×106cfu/mL时,叶片上的定殖量可达1.7×10^3cfu/g。浓度为1×10^8cfu/mL的菌液喷施叶面时,在喷雾后5 d菌量达到最高峰。综合来看,生防菌N24的最适喷施菌液浓度为1×10^6cfu/mL。添加增效因子后有利于双抗菌株在葡萄叶片表面的定殖,其中,添加壳聚糖的效果最好,其次为苏氨酸。添加磷酸氢二钾后的菌量与对照相比,没有显著差别。

In order to study colonization ability of Bacillus amyloliquefaciens on grape leaves, the strain N24 of Bacillus amyloliquefaciens was induced by rifampicin and streptomycin to obtain double resistant strains. The ob-tained strain could resist 320 μg/m L rifampicin and 150 μg/m L streptomycin stably and its characteristics weresame to wild strain. The experiment results of the double resistant strains colonized on grape leaves showed that af-ter grape leaves were sprayed with 1×104cfu/m L and 1×10^6cfu/m L of N24, the bacteria amount of double resistantstrains rose steeply from 5th day to 10 th day and reached a peak at 10 th day when the colonization ability and repro-ductive capacity were strongest. Especially when the initial bacterial concentration was 1×10^6cfu/m L, the amount ofN24 reached 1.7×10^3cfu/g, then declined after 10 th day. When concentration was 1×10^8cfu/m L, the amount of dou-ble resistant strains reached peak at 5th day. In conclusion, the most suitable concentration of N24 was 1×10^6cfu/m L when it was spayed to grape leaves. Adding the synergistic factor was conducive to the colonization of double re-sistant strains on grape leaf surface. Among them, the best was chitosan, followed by threonine. When potassium hy-drogen phosphate was added, there was no significant difference with control.