植物萃取物防治十字花科蔬菜炭疽病之篩選模式

Screening model of plant extracts for control of cruciferous vegetable anthracnose caused by Colletotrichum higginsianum

本研究蒐集29科57種植物材料，分別以酒精及水萃取兩種方式製成114種植物萃取液，以100倍稀釋液直接噴施於白菜植株上，測試其對十字花科蔬菜炭疽病（由Colletotrichum higginsianum引起）的防病效果，再取具有防病效果的44種植物萃取液，其中24種為酒精萃取液，20種為水萃取液，測試在培養基上的抑菌能力，發現其中31種萃取液具有抑菌效果，而12種萃取液不具抑菌效果，且全為水萃取液，推測後者具有誘導植物產生抗病性的能力。進一步將萃取液稀釋後分別測試其抑菌能力，結果顯示，以酒精萃取之生薑100倍，鼠尾草、樟葉及防風200倍，迷迭香、檳榔及大黃800倍等稀釋液均能完全抑制炭疽病菌孢子發芽與附著器之形成；另外，以酒精萃取的迷迭香200倍及大黃400倍，以及以水萃取無直接抑菌效果的檳榔100倍及生薑200倍等稀釋液具明顯抑制白菜炭疽病發生的效果。本研究證明先以植物體接種方式篩選植物萃取物，再分析具抑病效果之萃取物的抑菌能力，不但可獲得具抑菌能力之萃取物，而且可獲取具誘導抗病性之植物萃取物。

"Fifty-seven plant materials including Chinese medicinal herbs and aromatic herbs extracted by ethanol and water were evaluated for their suppression of disease severity and lesion number of cruciferous vegetable anthracnose caused by Colletotrichum higginsianum PA01. Each plant extract was diluted into 100-fold extract solution with distilled water and sprayed on the leaf surface of Pak-choi, one kind of cruciferous vegetables, then the spore suspension with 105 spore/ml of anthracnose pathogen PA-01 was inoculated on the extract-treated plants. Total 44 of 114 plant extracts showed an effective disease inhibition. Among 44 plant extracts including 24 ethanol extracts and 20 water extracts, 31 of them with 100-fold dilution showed strong inhibition ability on spore germination of C. higginsianum PA-01, but not for other 12 water extracts. Those water extracts showing an ability of anthracnose disease inhibition but not for spore germination inhibition were presumed to have the ability to induce disease resistance. The plant extracts with strong inhibitory effect of spore germination were further tested for their inhibition concentration. Data showed that the ethanol extracts of 100-fold-diluted ginger, 200-fold-diluted sage, camphor leaf, and Saposhnikoviae Radix, 800-fold-diluted rosemary, areca nut, and Rhei Rhizoma completely inhibited spore germination and appressorial formation of C. higginsianum PA-01. In addition, the ethanol extracts of 200-fold-diluted rosemary, and 400-fold-diluted Rhei Rhizoma, as well as the water extracts of 100-fold-diluted areca nut, and 200-fold-diluted ginger showed the effective suppression of anthracnose disease. In this study, it was proved that the screening model for selection of potential plant extracts with plant inoculation method first, then analyzed the antifungal activity of the extracts with disease inhibitory effect was not missed the plant extracts with an ability to induce disease resistance."