丁香及其主成分防治甘藍苗立枯病的功效

Effect of Clove and Its Major Component on Control of Rhizoctonia Damping-off of Cabbage Seedlings

林宗俊( T. C Lin) ； 鄭可大( K. T Cheng) ； 黃振文( J. W Huang)

《植物病理學會刊》 11卷4期 (2002/12) Pp. 189-198

https://doi.org/10.6649/PPB.200212_11(4).0004

摘要

甘藍立枯病菌(Rhizoctonia solani AG-4)引起甘藍幼苗猝倒與死亡的現象，是甘藍幼苗栽培的主要限制因子之一，在溫室的帶菌栽培介質中，添加0.5%(w/v)丁香可有效降低甘藍立枯病的發病率達52-60%。將丁香粉未利用不同溶劑萃取，並進行抑菌生物分析，結果証明由正己烷萃出之萃出物可完全抑制R. solani AG-4菌絲生長。進一步，以管柱層析法純化正己烷萃出物並做活性測試，結果發現管柱層析純化之主要成分的2500倍稀釋液可完全抑制R. solani AG-4菌絲的生長。此主要成分經核磁共振光譜儀NMR 300MHZ分析，確定為丁香酚(eugenol)，其化學分子式為C10H12O2。此外，丁香的抑菌物質具有揮發的燻蒸特性，在光學顯微鏡及掃描式電子顯微鏡下觀察，發現丁香燻蒸處理過之菌絲表面出現皺縮，細胞壁穿孔、原生質滲漏，菌絲或菌絲尖端腫脹破裂及菌絲分枝出現異常等現象。利用薄層色層分析檢測，發現丁香抑菌與殺菌的揮發性物質亦為丁香酚。綜合上述諸研究証明丁香添加於介質中防治甘藍立枯病的主要有效成分為丁香酚。

關鍵字

甘藍 ； 甘藍立枯病 ； 丁香 ； 丁香酚 ； 栽培介質

並列摘要

Damping-off disease caused by Rhizoctonia solani AG-4 is a serious disease of cabbage, especially in seedlings grown in culture medium. The treatment of peat moss medium, BVB No.4, infested by the pathogen with 0, 0.25, 0.5, 0.75, and 1 % (w/v) of clove was significantly effective in reducing the disease incidence of seedling damping-off. It showed markedly 52-60% reduction in the disease incidence at the rate of 0.5% (w/v) compared to non-treatment as a control. The similar results were also confirmed in three time large-scale experiments in the greenhouse. The powders of clove flower buds were extracted with methanol for three times. The combination of extractives was partitioned with n-hexane and ethyl acetate. Finally, the rest was extracted with water. The extractives from different solvents were tested for their bioactivity on mycelial growth of the pathogen. The n-hexane extractives showed significant effect on suppression of mycelial growth of R. solani AG-4. The n-hexane-soluble extractive was subjected to systemic separation and purification by column chromatography and thin layer chromatography. One major compound and two minor compounds were obtained and used to test their bioactivity. The mycelial growth of the pathogen was completely inhibited by 2500-fold dilution of the major compound of n-hexane-soluble extractive. In advance, this major compound was characterized by 1H NMR spectrum as eugenol. For fumigation effect of clove powder solution on mycelial growth of the pathogen, the inhibition of mycelial growth by clove-fumigant was increased with increasing the concentrations of clove in water solution. Observations under light microscope and scanning electron microscope indicated that the hyphae or hyphal tips of R. solani AG-4 swelled, plasma seeped around the hyphae, plasma leaked out, cell wall distorted, branched abnormal or fused with main hypha, hyphal tips warped or looped, and surface of hyphae wrinkled were caused by clove-fumigant treatment for 24hr. The clove-fumigant was also identified as eugenol by bioassay method and thin layer chromatography. The results suggest that the major component of clove inhibiting damping-off of cabbage seedlings is eugenol.

並列關鍵字

Cabbage ； Rhizoctonia damping-off ； Clove ； Eugenol ； Culture medium