利用牛津杯法筛选出对柑橘绿霉病菌（指状青霉）有最佳抑制作用的中草药提取物，并通过测定培养液电导率变化等对其抑菌机理作进一步研究。结果表明：桂枝、桂皮、香薷等乙醇提取物对指状青霉均有较好的抑制效果，抑制圈均在20 mm以上，其中以桂枝的抑菌活性最佳，对指状青霉的抑制圈大小达31.56±0.66 mm，最小抑菌浓度（MIC）和最小杀菌浓度（MFC）分别为6.25 mg/mL、12.5 mg/mL，且其抑菌效果显著优于化学杀菌剂百可得。同时桂枝提取物对指状青霉菌的孢子萌发及菌丝生长发育也有较强的抑制作用，在提取液处理浓度为50 mg/mL时，孢子萌发抑制率高达99.007%，菌丝体细胞膜通透性增强，菌丝体可溶性蛋白及总糖含量分别只有1187.18 μg/g及0.307%，菌丝形态呈现畸形甚至断裂，因而桂枝提取物对柑橘绿霉病菌有明显的抑菌活性，其抑菌作用主要是通过破坏细胞膜结构，扰乱菌丝物质代谢活动来实现的。

The antifungal activity of some Chinese herb extracts on citrus green mold (Penicillium Digitatum) were screened by Cylinder-plate method, the potential antifungal mechanism of the optimum extracts were investigated by determining the changes of electrical conductivity of culture media. The results showed that the ethanol extracts of Cinnamomi Ramulus, Cinnamomi Cortex and Mosla Chinensis had better inhibition effect on the green mold, the inhibition zones were all over 20 mm. Moreover, Cinnamomi Ramulus displayed remarkable inhibition effect, which was even better than Bellkute. The inhibition zone, minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were 31.56 ± 0.66 mm, 6.25 mg/mL and 12.5 mg/mL, respectively. In addition, the research also showed that Cinnamomi Ramulus extracts effectively inhibited spore germination and mycelial growth and development. When the concentration of Cinnamomi Ramulus extracts was 50 mg/mL, the conidia germination inhibition rate were up to 99.007%; the permeability of cell plasma membrane and cellular components exosmose were increased; the total soluble protein and sugar contents of mycelium were 1187.18 μg/g and 0.307%, respectively; and the morphology of mycelium were malformed and fractured. Thus, Cinnamomi Ramulus ethanol extracts have good antifungal activity through disturbing the structure of cellular membrane and mycelium metabolism.

“十二五”科技支撑计划项目(2012BAD38B03-2)；国家自然科学基金项目(31160343)；江西省教育厅科技落地计划项目(111)；江西省“赣博英才555工程（2012），江西省博士后科研择优资助项目(2013KY31)；留学人员科技活动项目(人社厅函[2013]277号)资助，中国博士后科学基金项目（2013M541870）