Phytotoxic Activities of Crude Extracts of Eucalyptus camaldulensis in Taiwan

台灣桉樹萃取物之植物毒性

黎凱允(Kai-Yun Li) ； 鄭雅銘(Ya-Ming Cheng) ； 王相華(Hsiang-Hua Wang) ； 許原瑞(Yuan-Jui Hsu) ； 徐玲明(Lin-Ming Hsu) ； 劉又彰(You-Jang Liou) ； 王慶裕(Ching-Yuh Wang)

《中華民國雜草學會會刊》 35卷2期 (2014/12) Pp. 81-95

https://doi.org/10.6274/WSSROC-2013-035(2)-081

摘要

為發展生物性除草劑，本試驗評估台灣桉樹（＂Eucalyptus camaldulensis L.＂）之植物毒性，乃利用敏感性生物檢定材料白莧（＂Amaranthus gangeticus＂ L.）驗證桉樹葉片萃取精油過程中產生之熱水萃取物與精油之植物毒性。根據白莧種子發芽與胚根伸長對於熱水萃取物與其主要成分gallic acid（GA）之劑量反應，認為其中有些熱穩定成分參與抑制種子發芽。同時，利用相同生物檢定系統發現由精油引起之劑量反應趨勢類似1,8-cineole，但精油有較大之活性且胚根伸長反應較種子發芽敏感。若考慮精油中之1,8-cineole實際含量，推測精油中可能含有其他成分具有較強之植物毒性。在抑制胚根伸長達50％之相同劑量處理下，熱水萃取物與GA具有相似之有絲分裂抑制趨勢，顯現此酚類化合物在萃取物中之角色。此外，1,8-cineole及精油（僅含有2％的1,8-cineole）分別抑制胚根伸長達77％與31％，顯示在整個白莧胚根伸長受到1,8-cineole抑制之過程中，根部細胞有絲分裂停滯僅為一小部分機制。從顯微鏡觀察下，也發現GA或1,8-cineole均不會影響白莧有絲分裂四個時期之細胞數目。

關鍵字

有絲分裂

並列摘要

In order to estimate the phytotoxic activity of eucalyptus (＂Eucalyptus camaldulensis＂ L.) in Taiwan for developing bioherbicide, phytotoxic activities of boiling-water extract and volatile essential oil, two main parts produced during essential oil extraction, from eucalyptus leaves were confirmed with a sensitive edible amaranth (＂Amaranthus gangeticus＂ L.). The dose-responses of this amaranth, based on its seed germination and radicle elongation, to the boiling-water extract and gallic acid (GA), a major component, suggest that some heat-stable compounds in this extract were involved in the inhibition of seed germination. Meanwhile, with the same bioassay, the dose response tendency caused by essential oil from this eucalyptus appeared to resemble that of 1,8-cineole, but the essential oil had higher activity than that of 1,8-cineole, with radicle elongation being more sensitive to the treatments than seed germination. Furthermore, taking into consideration of its estimated content of 1,8-cineole, the eucalyptus essential oil must have contained additional components with higher potency. At equivalent dosages causing 50% inhibition of radicle elongation, boiling-water extract and GA showed similar mitosis inhibition tendency, revealing a potential role of this phenolic compound in the extract; and 1,8-cineole and eucalyptus essential oil (containing only 2% of 1,8-cineole), respectively, inhibited 77% and 31% radicle elongation indicates that an arrest of root cell mitosis represented only a minor part of the mechanisms involved in the overall retardation of amaranth radicle elongation by 1,8-cineole. Microscopic observation showed neither GA nor 1,8-cineole affected the number of mitotic cells at all four division stages in the edible amaranth.

並列關鍵字

gallic acid ； 1,8-cineole ； mitosis