大蒜与 3 种药用作物对烟草炭疽病菌的抑菌效果

烟草炭疽病是烟草苗期发生的一种主要病害,采用菌丝生长速率法,研究了大蒜、玄参、川明参、半夏等作物茎叶根系提取物、根系分泌物及其组合对烟草炭疽病菌的抑菌效果.结果表明:1)大蒜、玄参、川明参、半夏的茎叶和根系提取物对烟草炭疽病菌都有不同程度的抑制作用,抑制作用随提取物浓度增大而增强;大蒜抑菌活性最强,其茎叶和根系抑制率在0.50g/mL时均达到100%,玄参次之,茎叶抑制率在0.25g/mL时最高达58.40%,根系在0.5g/mL时最高(57.20%),川明参和半夏抑制率不高;大蒜鳞茎抑菌活性强于茎叶,玄参茎叶抑菌活性强于根系;川明参茎叶、根系提取物组合增益效应明显;2)大蒜、玄参、川明参、半夏根系分泌物对烟草炭疽病菌均表现出一定的抑制作用,随根系分泌物浓度增大而增强,抑菌强度由大到小为大蒜,玄参,川明参,半夏;3)提取物和根系分泌物组合的抑菌性,玄参、川明参介于提取物组合与根系分泌物之间,半夏略有降低.得出大蒜、玄参、川明参有防控烟草炭疽病的应用潜力.

The Antifungal Effects of Garlic and Three Medicinal Crops on Colletotrichum nicotianae

Tobacco anthracnose (Colletotrichum nicotianae) is a major disease that occurs at the seedling stage of tobacco. In this study, the mycelial growth rate method was employed to investigate the antifungal effects of the extracts from the stem-leaf and root, the root exudates, and the combinations of garlic, Scrophularia ningpoensis, Chuanmingshen violaceum and Pinellia ternate on Colletotrichum nicotianae. Stem-leaf and root extracts of garlic, S. ningpoensis, C. violaceum and P. ternata all exhibited, in different extents, antifungal activities, and the inhibition increased with increasing concentration of the extract. Garlic showed the strongest antifungal activity, the inhibition rate of its steam-leaf and root extracts being as high as 100% at 0.50 g/mL, The next one was S. ningpoensis, the inhibition rate of its steam-leaf extracts at 0.25 g/mL and root extracts at 0.50 g/mL being up to 58.40% and 57.20%, respectively. The inhibitory effect of C. violaceum and P. ternata was relatively low. The antifungal activity of garlic bulb was stronger than that of its stem-leaf while the stem-leaf of S. ningpoensis showed stronger inhibitory effect than its root extracts. The combination of stem-leaf and root extracts of C. violaceum exhibited a significant gain effect in fungistasis. The root exudates of garlic, S. ningpoensis, C. violaceum and P. ternata showed fungistasis to C. nicotianae, and their fungistasis was enhanced with increasing concentration. Their antifungal effect appeared in the order of garlic > C. violaceum > S. ningpoensis > P. ternata. The antifungal activity of the combination of extracts and root exudates from S. ningpoensis and C. violaceum was located between their extracts and root exudates, and the antifungal activity of P. ternate decreased slightly. Conclusion: Garlic, S. ningpoensis and C. violaceum can be potentially applied to prevent and control tobacco anthracnose.