This study was undertaken to explore new antifungal compounds from the methanolic extract of G. sinaicus. Two cardenolide compounds were isolated and identified by GC-MS as cardenolide glycoside, 15-hydroxy-3,4,5,6-de...This study was undertaken to explore new antifungal compounds from the methanolic extract of G. sinaicus. Two cardenolide compounds were isolated and identified by GC-MS as cardenolide glycoside, 15-hydroxy-3,4,5,6-dehydrocalotropin and cardenolide genin, 3,4,5,6-dehydrocalotropagenin. The antifungal activity of these compounds was assessed. Results revealed that both compounds showed pronounced fungicidal activity against both soil borne fungi, R. solani, F. oxysporium, and postharvest fungi, R. stolonifer, P. digtatum, compared to the standard fungicides, flutolanil and copper oxychloride, respectively. The ECs0 values of the cardenolide genin were 0.703, 13.63 and 4.22, 8.403 lag/mL forR. solani, F. oxysporium andR. stolonifer, P. digtatum respectively. On the other hand, the ECs0 values of the standard fungicide, flutolanil, were 9.49 and 61.22 ~tg/mL against R. solani and F. oxysporium. While the ECso values of copper oxychloride were 279.94 and 187.13 p.g/mL against R. stolonifer and P. digtatum, respectively. The results showed that cellulase, PME, PPO of the tested fungi was more sensitive than to cardenolide genin. The strong antifungal activity of cardenolide genin reported in this study indicated that has a potential to be used as fungicides.展开更多
Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its eff...Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.展开更多
文摘This study was undertaken to explore new antifungal compounds from the methanolic extract of G. sinaicus. Two cardenolide compounds were isolated and identified by GC-MS as cardenolide glycoside, 15-hydroxy-3,4,5,6-dehydrocalotropin and cardenolide genin, 3,4,5,6-dehydrocalotropagenin. The antifungal activity of these compounds was assessed. Results revealed that both compounds showed pronounced fungicidal activity against both soil borne fungi, R. solani, F. oxysporium, and postharvest fungi, R. stolonifer, P. digtatum, compared to the standard fungicides, flutolanil and copper oxychloride, respectively. The ECs0 values of the cardenolide genin were 0.703, 13.63 and 4.22, 8.403 lag/mL forR. solani, F. oxysporium andR. stolonifer, P. digtatum respectively. On the other hand, the ECs0 values of the standard fungicide, flutolanil, were 9.49 and 61.22 ~tg/mL against R. solani and F. oxysporium. While the ECso values of copper oxychloride were 279.94 and 187.13 p.g/mL against R. stolonifer and P. digtatum, respectively. The results showed that cellulase, PME, PPO of the tested fungi was more sensitive than to cardenolide genin. The strong antifungal activity of cardenolide genin reported in this study indicated that has a potential to be used as fungicides.
文摘Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.
