目的 筛选西红花Crocus sativus球茎腐烂病拮抗真菌,探讨其抑菌机制。方法 以前期分离得到的24株西红花内生真菌为材料,采用平板对峙法筛选球茎腐烂病拮抗真菌;应用ITS分子技术进行菌种鉴定,用扫描电镜观察拮抗后病原菌尖孢镰刀菌Fusarium oxysporum菌丝形态;检测拮抗菌株CS05菌丝产生β-1,3-葡聚糖酶与几丁质酶的含量及病原菌产碱性磷酸酶(alkaline phosphatase,AKP)的含量。结果 筛选得到对尖孢镰刀菌有显著拮抗作用的内生真菌8株,其中CS05抑制效果最好,相对抑制率为(76.53±3.82)%;将CS05鉴定为担子菌门多孔菌目栓菌属真菌变色栓菌Trametes versicolor;CS05能产生β-1,3-葡聚糖酶与几丁质酶,促使尖孢镰刀菌胞外AKP含量增加,菌丝出现稀疏紊乱、缠绕皱缩等现象。结论 西红花内生真菌CS05能较好地拮抗球茎腐烂病菌尖孢镰刀菌,为西红花球茎腐烂病的生物防治提供了参考依据。

Objective To screen antagonistic fungi against corm rot pathogenic fungus of Crocus sativus (Fusarium oxysporum) and explore its antifungal mechanism. Methods Twenty-four endophytic fungi isolated from C. sativus were used to screen antagonistic fungi against corm rot pathogenic fungus via plate confrontation method. Molecular biological methods were used to identify the antagonistic strain. The antifungal mechanism was studied by scanning electron microscope, detecting the β-1,3-glucanase, chitinase and alkaline phosphatase activity. Results Eight endophytic fungi strains were screened since they possessed a significant antagonistic effect against F. oxysporum. Among them, CS05 had the best inhibitory effect whose relative inhibitory rate was (76.53 ±3.82)%. Moreover, CS05 was identified as Trametes versicolor. Enzyme activity assay showed that CS05 could produce β-1,3-glucanase and chitinase, and increase extracellular alkaline phosphatase content of F. oxysporum significantly, causing sparse and disordered growth, twining and shrinking of F. oxysporum mycelia. Conclusion The endophytic fungus CS05 could effectively antagonize F. oxysporum, which provided a reference for the biological control of corm rot of C. sativus.

R286.2

浙江省一流学科（中药学）开放基金项目（ZYAOX2018011）；浙江省公益技术研究计划项目（LGN21H280001）；浙江中医药大学人才专项（2021ZR09）；浙江省医药卫生青年创新人才支持计划（2022492838）