Objective: To isolate endophytic fungi from Elaeocarpus sylvestris(E. sylvestris) and to isolate antioxidant compounds from a potential source fungus.Methods: Endophytic fungi were isolated from fresh leaves and stems...Objective: To isolate endophytic fungi from Elaeocarpus sylvestris(E. sylvestris) and to isolate antioxidant compounds from a potential source fungus.Methods: Endophytic fungi were isolated from fresh leaves and stems of E. sylvestris and identified based on DNA analysis. 1,1-Diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity was used to evaluate the antioxidant activity of the fungi. The potential antioxidant fungus was further studied to isolate antioxidant compounds. The isolated compounds were identified by melting point analysis, optical rotation, spectral analysis using a UV spectrophotometer, high resolution fast atom bombardment mass spectrometry, X-ray crystallography analysis,~1H nuclear magnetic resonance analysis and ^(13)C nuclear magnetic resonance analysis. The isolated compounds were evaluated with DPPH radical scavenging, reducing power, and b-carotene bleaching assays.Results: Seven endophytic fungi were successfully isolated from E. sylvestris and identified as Pestalotiopsis sp. EST 01, Pestalotiopsis sp. EST 02, Diaporthales sp. EST03, Meyerozyma sp. EST 04, Diaporthales sp. EST 05, Pestalotiopsis sp. ESL 01, and Pseudocercospora sp. ESL 02. Of the seven fungi, Pseudocercospora sp. ESL 02 had the highest antioxidant activity [IC50=(30.54 ± 0.88) mg/mL]. From that fungus, two compounds identified as terreic acid(1) and 6-methylsalicylic acid(2) were isolated with an IC50 of DPPH radical scavenging activity of(0.22 ± 0.02) mmol/L and(3.87 ± 0.27)mmol/L, respectively. The compounds also had good activities from the reducing power and b-carotene bleaching assays.Conclusions: The Pseudocercospora sp. ESL 02 fungus isolated from E. sylvestris looks promising as a novel source of terreic acid.展开更多
An investigation to assess the spatial structure and severity of Pseudocercospora leaf and fruit spot disease (PLFSD) on citrus trees in cocoa-based agroforests was carried out in three contrasting ecological zones in...An investigation to assess the spatial structure and severity of Pseudocercospora leaf and fruit spot disease (PLFSD) on citrus trees in cocoa-based agroforests was carried out in three contrasting ecological zones in southern Cameroon, viz: 1) the humid forest zone, 2) the degraded forest zone, and 3) the forest-savannah transition zone. Two main parameters were investigated viz: 1) the spatial structure of cocoa based agroforests, and 2) the disease severity. In total, the spatial structure of 19 cocoa-based agroforests was analysed using the Ripley K(r) function, meanwhile the collection of epidemiological data that consisted of noting the presence of PLFSD spots on leaves and fruits on 438 citrus trees was used to characterise the severity of the disease. Results showed that, the spatial structure of citrus trees in these agroforests investigated were regular in seven plots, random in nine, and aggregated in three. Aggregated plots presented a significantly higher mean of disease severity on leaves and fruits (28.55 and 30.37 respectively), as compared to randomised (20.91 and 16.32 respectively) and regular plots (16.28 and 14.97 respectively), at P-value < 0.05. These results suggest that the spatial structure of citrus trees in the cocoa-based agroforests studied influences the severity of PFLSD. Proper integrated control measures can therefore be initiated, leading to a considerable reduction of the use of manufactured inputs, and thereby, the cost of production of citrus fruits.展开更多
本文报道采自广东热带地区的15种半知菌,其中有4个新种和2个中国新记录种:寄生在毛麝香 Adenosma glutinosum (L.) Druce上的毛麝香假尾孢 Pseudocercospora adenosmae Y. L. Guo,生于柑橘属Citrus sp.植物上的柑橘假尾孢 P. citri Y. L...本文报道采自广东热带地区的15种半知菌,其中有4个新种和2个中国新记录种:寄生在毛麝香 Adenosma glutinosum (L.) Druce上的毛麝香假尾孢 Pseudocercospora adenosmae Y. L. Guo,生于柑橘属Citrus sp.植物上的柑橘假尾孢 P. citri Y. L. Guo,生于木防己属Cocculus sp.植物上的木防己生假尾孢 P. cocculigena Y. L. Guo,生于腺萼木属Mycetia sp.植物上的腺萼木假尾孢P. mycetiae Y. L. Guo,生于西番莲Passiflora coerulea L.上的西番莲生尾孢Cercospora passifloricola Chupp和生于吴茱萸属Evodia sp.植物锈菌春孢子器上的春孢器生枝孢Cladosporium aecidiicola Th黰.。文中为新种提供了拉丁文简介、英文描述并附图,研究的标本保存在中国科学院微生物研究所菌物标本馆(HMAS)。展开更多
文摘Objective: To isolate endophytic fungi from Elaeocarpus sylvestris(E. sylvestris) and to isolate antioxidant compounds from a potential source fungus.Methods: Endophytic fungi were isolated from fresh leaves and stems of E. sylvestris and identified based on DNA analysis. 1,1-Diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity was used to evaluate the antioxidant activity of the fungi. The potential antioxidant fungus was further studied to isolate antioxidant compounds. The isolated compounds were identified by melting point analysis, optical rotation, spectral analysis using a UV spectrophotometer, high resolution fast atom bombardment mass spectrometry, X-ray crystallography analysis,~1H nuclear magnetic resonance analysis and ^(13)C nuclear magnetic resonance analysis. The isolated compounds were evaluated with DPPH radical scavenging, reducing power, and b-carotene bleaching assays.Results: Seven endophytic fungi were successfully isolated from E. sylvestris and identified as Pestalotiopsis sp. EST 01, Pestalotiopsis sp. EST 02, Diaporthales sp. EST03, Meyerozyma sp. EST 04, Diaporthales sp. EST 05, Pestalotiopsis sp. ESL 01, and Pseudocercospora sp. ESL 02. Of the seven fungi, Pseudocercospora sp. ESL 02 had the highest antioxidant activity [IC50=(30.54 ± 0.88) mg/mL]. From that fungus, two compounds identified as terreic acid(1) and 6-methylsalicylic acid(2) were isolated with an IC50 of DPPH radical scavenging activity of(0.22 ± 0.02) mmol/L and(3.87 ± 0.27)mmol/L, respectively. The compounds also had good activities from the reducing power and b-carotene bleaching assays.Conclusions: The Pseudocercospora sp. ESL 02 fungus isolated from E. sylvestris looks promising as a novel source of terreic acid.
文摘An investigation to assess the spatial structure and severity of Pseudocercospora leaf and fruit spot disease (PLFSD) on citrus trees in cocoa-based agroforests was carried out in three contrasting ecological zones in southern Cameroon, viz: 1) the humid forest zone, 2) the degraded forest zone, and 3) the forest-savannah transition zone. Two main parameters were investigated viz: 1) the spatial structure of cocoa based agroforests, and 2) the disease severity. In total, the spatial structure of 19 cocoa-based agroforests was analysed using the Ripley K(r) function, meanwhile the collection of epidemiological data that consisted of noting the presence of PLFSD spots on leaves and fruits on 438 citrus trees was used to characterise the severity of the disease. Results showed that, the spatial structure of citrus trees in these agroforests investigated were regular in seven plots, random in nine, and aggregated in three. Aggregated plots presented a significantly higher mean of disease severity on leaves and fruits (28.55 and 30.37 respectively), as compared to randomised (20.91 and 16.32 respectively) and regular plots (16.28 and 14.97 respectively), at P-value < 0.05. These results suggest that the spatial structure of citrus trees in the cocoa-based agroforests studied influences the severity of PFLSD. Proper integrated control measures can therefore be initiated, leading to a considerable reduction of the use of manufactured inputs, and thereby, the cost of production of citrus fruits.
基金Supported by the National Science Foundation of China (Approved No. 39730020)
文摘本文报道采自广东热带地区的15种半知菌,其中有4个新种和2个中国新记录种:寄生在毛麝香 Adenosma glutinosum (L.) Druce上的毛麝香假尾孢 Pseudocercospora adenosmae Y. L. Guo,生于柑橘属Citrus sp.植物上的柑橘假尾孢 P. citri Y. L. Guo,生于木防己属Cocculus sp.植物上的木防己生假尾孢 P. cocculigena Y. L. Guo,生于腺萼木属Mycetia sp.植物上的腺萼木假尾孢P. mycetiae Y. L. Guo,生于西番莲Passiflora coerulea L.上的西番莲生尾孢Cercospora passifloricola Chupp和生于吴茱萸属Evodia sp.植物锈菌春孢子器上的春孢器生枝孢Cladosporium aecidiicola Th黰.。文中为新种提供了拉丁文简介、英文描述并附图,研究的标本保存在中国科学院微生物研究所菌物标本馆(HMAS)。
