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【目的】从桃树根部组织中分离、筛选能够防治桃褐腐病害的内生拮抗菌,从细胞学水平探究其抑制机理。【方法】采用平板对峙法筛选对桃褐腐病菌(Monilinia fructicola)有拮抗作用的内生细菌,调查内生拮抗细菌的形态学及生理生化特性,通过细菌16S r RNA基因测序分析菌株的系统发育学特征。通过果实离体实验检测内生拮抗细菌的抗菌效果,使用电子显微镜观察受抑制的桃褐腐病菌菌丝、孢子的形态以及细胞内部结构变化。【结果】从桃树根部组织中复筛分离得到的3株内生细菌对桃褐腐病防效高且稳定,经鉴定3株细菌均为枯草芽孢杆菌。果实离体试验表明,3株内生细菌均明显抑制了桃褐腐病的发生。通过电子显微镜观察,发现受拮抗细菌抑制的桃褐腐病菌的菌丝明显变细、杂乱且打结缠绕成团,孢子普遍干瘪变大、破裂,细胞质外渗。【结论】从桃树根部组织中得到的3株内生细菌对桃褐腐病菌的生长均有明显的抑制作用,可以作为防治桃褐腐病的新选择,具有进一步研究价值。
【Objective】 The objective of this study was to isolate and screen endophytic antagonistic bacteria that can prevent and cure peach brown rot disease from the root tissue of peach tree and to explore its inhibitory mechanism from cytology level. 【Method】 Endophytic bacteria antagonistic to Monilinia fructicola were screened by plate confrontation method. The morphology and physiological and biochemical characteristics of endophytic antagonistic bacteria were investigated. The bacterial phylogeny was analyzed by bacterial 16S rRNA gene sequencing Learn characteristics. The antibacterial effect of endophytic antagonistic bacteria was detected by in vitro experiments, and the morphology and intracellular structure changes of the mycelium and spores of the inhibited peach rot pathogen were observed by electron microscope. 【Result】 The results showed that the three endophytic bacteria isolated from the roots of peach tree were highly effective and stable to perennial brown rot. Three strains of Bacillus subtilis were identified. Fruit in vitro tests showed that three endophytic bacteria were significantly inhibited peach brown rot disease. Observation by electron microscope showed that the hyphae of peach brown rot bacteria inhibited by the antagonistic bacteria were obviously thinned, cluttered and tangled into clusters, and the spores were generally dry and bulky, ruptured and the cytoplasm extravasated. 【Conclusion】 The results showed that the three endophytic bacteria obtained from peach root tissue could obviously inhibit the growth of Botryosphaeria berengeriana, which could be used as a new choice to control perennial brown rot with further research value.