中药材

目的：明确湖北多花黄精根腐病致病菌种类，并研究卡氏芽孢杆菌对该致病菌的抑制作用，为多花黄精根腐病的综合防治提供依据。方法：从多花黄精根腐病样品中分离病原菌；经形态学鉴定和ITS序列及tef1-α基因序列分析，明确病原菌种类；通过牛津杯法、扫描电镜以及荧光显微镜研究卡氏芽孢杆菌ST-1对病原菌的抑制作用及可能机制。结果：从多花黄精根腐病病样分离得到病原菌株887为尖孢镰刀菌Fusarium oxysporum;卡氏芽孢杆菌ST-1及其脂肽粗提物可抑制尖孢镰刀菌，脂肽粗提物处理浓度为308μg/mL(EC₅₀)时，可导致尖孢镰刀菌菌丝出现膨大皱缩，细胞内容物外溢，细胞膜被破坏，细胞质凝聚及活性氧激增现象。结论：引起湖北多花黄精根腐病致病菌为尖孢镰刀菌F.oxysporum,卡氏芽孢杆菌ST-1对其有较好的防治效果。

Objective: To identify the pathogenic fungi causing root rot of Polygonatum cyrtonema in Hubei, and to study the inhibitory effect of Bacillus cabrialesii on this pathogen, aiming to provide a scientific basis for the comprehensive prevention and treatment of root rot of Polygonatum cyrtonema.Methods: The pathogen was isolated from samples of Polygonatum cyrtonema root rot, the species of pathogenic bacteria were identified by morphological identification, ITS sequence and tef1-α gene sequence analysis.The inhibition effect and possible mechanism of Bacillus cabrialesii ST-1 on pathogenic bacteria were studied by Oxford cup method, scanning electron microscope and fluorescence microscope.Results: The strain 887 isolated from Polygonatum cyrtonema root rot samples was identified as Fusarium oxysporum.Bacillus cabrialesii ST-1 and its lipopeptide crude extract could inhibit Fusarium oxysporum.The lipopeptide crude extract with the treatment concent of 308 μg/mL(EC₅₀) caused Fusarium oxysporum hyphae to swell and shrink, with the cell contents leaking, cell membranes being destroyed, cytoplasm condensing, and reactive oxygen species(ROS) levels increasing significantly.Conclusion: The pathogen causing root rot of Polygonatum cyrtonema in Hubei is Fusarium oxysporum,Bacillus cabrialesii ST-1 shows good control efficacy against it.