毛殼菌對嘉磷塞忍受性之研究

Abstract

自台灣地區施用過嘉磷塞的田土中，分離出對嘉磷塞具有忍受性的菌種。發現Aspergillus niger, Chaetomium aureum, C. bostrychodes, C. chiversii, C. convolutum, C. crispatum, C. cupreum, C. globosum, C. gracile, C. indicum, C. megalocarpum, C. succineum, Cladosporium sp., Fusarium solani, Fusarium sp., Mucor sp., Penicilium sp., Pythium spinosum, P. splendens, Rhizopus sp., Rhizoctonia solani, Sclerotium rolfsiii, Scopulariopsis sp.及Trichoderma harzianum等12屬24種真菌。將所蒐集到的其中17種土壤真菌培養在馬鈴薯葡萄糖洋菜培養基中，進行不同濃度嘉磷塞對這些真菌的生長測試。結果顯示，嘉磷塞由1 mM至24 mM時，C. aureum, C. cupreum及F. solani之菌落生長與各該菌種在控制組(0 mM)之菌絲相對生長比率，皆顯著（P＜0.05）高於其它真菌。當液態培養馬鈴薯葡萄糖培養基含有嘉磷塞濃度由1 mM至4 mM時，C. aureum與C. cupreum之菌落生長淨重及各該菌種與控制組(0 mM)之菌絲相對淨重比率，皆顯著（P＜0.05）高於其他毛殼菌。嘉磷塞由1 mM至2 mM時，C. aureum與C. cupreum之嘉磷塞降解，皆顯著（P＜0.05）高於其他毛殼菌。C. aureum與C. cupreum會產生紅色的分泌物，該紅色分泌物在其他毛殼菌並不會產生；此紅色分泌物能增加C. aureum與C. cupreum對嘉磷塞的忍受性。毛殼菌降解嘉磷塞降解途徑，經由氣相層析儀的分析，初代謝物為aminomethylphosphonic acid (AMPA)，且各個毛殼菌的降解能力不同。添加C. aureum紅色的分泌物於耐嘉磷塞之基因轉殖大豆與非基因轉殖大豆於嘉磷塞環境中生長，添加C. aureum紅色的分泌物可使非基因轉殖大豆生長狀況如基因轉殖大豆。添加C. cupreum紅色的分泌物在含有嘉磷塞的環境中，可抑制F. solani, P. spinosum, P. splendens, R. solani與 S. rolfsiii的菌落生長。

Total isolates of soil fungi were isolated from the Taiwan forest nursery soils, that were previously applied with glyphosate before fungal isolation. Twenty-four species were identified from these 2474 isolates, viz. Aspergillus niger, Chaetomium aureum, C. bostrychodes, C. chiversii, C. convolutum, C. crispatum, C. cupreum, C. globosum, C. gracile, C. indicum, C. megalocarpum, C. succineum, Cladosporium sp., Fusarium solani, Fusarium sp., Mucor sp., Penicilium sp., Pythium spinosum, P. splendens, Rhizopus sp., Rhizoctonia solani, Sclerotium rolfsiii, Scopulariopsis sp. and Trichoderma harzianum. Seventeen of the isolates from the twenty-four species were cultured on PDA with different concentrations of glyphosate ranging from 0 mM to 120 mM. When the glyphosate concentrations were amended between 1 mM and 24 mM, the mycelial relative growth rates of C. aureum, C. cupreum and F. solani were significantly different from those of other species. When the glyphosate concentrations were amended between 1 mM and 4 mM, the relative percentage of mycelial growth weight of C. aureum and C. cupreum was significantly different from that of other Chaetomium species. When the glyphosate concentrations were amended between 1 mM and 2 mM, the percentage of glyphosate biodegradation of C. aureum and C. cupreum was significantly different from that of other Chaetomium species. Both C. aureum and C. cupreum produced the red secrets, but other Chaetomium species did not produce those. The red secrets produced by C. aureum and C. cupreum could be the main cause that increased their tolerance to glyphosate. Metabolism of the phosphate herbicide glyphosate is aminomethylphosphonic acid (AMPA) by Chaetomium spp. analyzed by gas chromatography. Non-genetically modified organism soybean seeds added with red secretion produced by C. aureum grew as well as the genetically modified organism soybean seeds on glyphosate. Mycelia of F. solani, P. spinosum, P. splendens, R. solani and S. rolfsiii were inhibited by red secretion produced by C. cupreum on glyphosate.