[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After n...[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.展开更多
At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and ...At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and safety of medicinal material. Biological pesticides are rapidly developed due to their characteristics of high efficiency, low toxicity and residue. This study aimed to introduce the specific property of biological pesticides, review the classification of biological pesticides and their application in medicinal plants, analyze the problems in the production and utilization process of biological pesticides, and forecast the developmental prospect.展开更多
The widespread use of agrochemicals and its possible negative impacts on humans and the environment remains a highly topical and controversial issue. Of particular concern here are chemicals that can disturb an organ...The widespread use of agrochemicals and its possible negative impacts on humans and the environment remains a highly topical and controversial issue. Of particular concern here are chemicals that can disturb an organism＇s endocrine system. Referring to the precautionary principle, the objective of the research project start2 is to develop management strategies that help reduce possible risks for httmans and the environment of endocrine active agrochemicals. As an empirical basis we combined qualitative and quantitative methods and initiated two expert dialogues. Our findings underpin the well known fact that the use of agrochemicals is complex and dependent on more than the individual attitudes of farmers. Agricultural plant protection management is the collective product of a complex agricultural system, which encompasses treatment, marketing, industry and agricultural consultation as well as agricultural teaching institutions and relevant scientific disciplines. Successful management strategies for risk reduction in the context of hormonally active agrochemicals thus need to involve all actors within this system. The paper proposes a strategy that promotes participation by enabling learning processes among these actors.展开更多
One of the traditional games played among the Yoruba people of South Western Nigeria utilizes the seeds ofDioclea reflexa. An investigation into the current status of the game was conducted to determine the extent to ...One of the traditional games played among the Yoruba people of South Western Nigeria utilizes the seeds ofDioclea reflexa. An investigation into the current status of the game was conducted to determine the extent to which it is still played. Although results indicate that the game is still being played in the rural areas, it also shows that it is steeply decreasing in popularity. About 6.6% of respondents interviewed have never heard of the game, while about 77% have played, or still play the game. Overall 17% of all respondents, or 22% of those who have ever played, still play the game. About 26% of respondents are optimistic about the game surviving their generation. The decline in popularity is attributable to decreasing proportion of youths in rural areas due to rural-urban migration, emergence of computer games, and scarcity of the seeds. Cultivation of D. reflexa plant for the game, food and medicinal purposes is recommended.展开更多
The solubilities of two β-agonists, cimaterol and mabuterol, in supercritical carbon dioxide (SF-CO2) were measured by a recirculating method at temperatures of 40℃ and 60℃ and pressures between 9 MPa to 49 MPa.The...The solubilities of two β-agonists, cimaterol and mabuterol, in supercritical carbon dioxide (SF-CO2) were measured by a recirculating method at temperatures of 40℃ and 60℃ and pressures between 9 MPa to 49 MPa.The compounds exhibit very limited solubilities in the range of 10^-5 to 10^-7 (mole fraction). Cimaterol has a higher solubility than that of mabuterol. The experimental data of solubility were correlated by four density-based models.The correlation accuracy highly depends on the system investigated, which is mainly determined by the density ranges and temperature.展开更多
Allelopathy importance and its application under field conditions are reviewed. Recent achievements in the field of plant protection are mainly considered and presented. Natural chemicals of potential use as pesticide...Allelopathy importance and its application under field conditions are reviewed. Recent achievements in the field of plant protection are mainly considered and presented. Natural chemicals of potential use as pesticides, commercialized natural products of pesticidal properties are included. Reported plants of pest control properties, their targeted agricultural pests, formulations, methods of application and activity under field conditions are presented. Allelopathic plant species and implications on their use in the field, positive and negative impacts on cultivated crop species and agricultural pests are discussed. Some research difficulties and experimental methodology problems are mentioned. Prospects of allelopathy as a future strategy for pest management, development of eco-friendly biopesticides and importance for sustainable agriculture and recent developments in allelopathy research are discussed.展开更多
基金Supported by Basic Research Fund for Central Nonprofit Institutes(Agro-environmental Protection Institute of Ministry of Agriculture)~~
文摘[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.
基金Supported by "Twelfth Five-Year" National Technology Support Program(2011BAI-06B01)~~
文摘At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and safety of medicinal material. Biological pesticides are rapidly developed due to their characteristics of high efficiency, low toxicity and residue. This study aimed to introduce the specific property of biological pesticides, review the classification of biological pesticides and their application in medicinal plants, analyze the problems in the production and utilization process of biological pesticides, and forecast the developmental prospect.
文摘The widespread use of agrochemicals and its possible negative impacts on humans and the environment remains a highly topical and controversial issue. Of particular concern here are chemicals that can disturb an organism＇s endocrine system. Referring to the precautionary principle, the objective of the research project start2 is to develop management strategies that help reduce possible risks for httmans and the environment of endocrine active agrochemicals. As an empirical basis we combined qualitative and quantitative methods and initiated two expert dialogues. Our findings underpin the well known fact that the use of agrochemicals is complex and dependent on more than the individual attitudes of farmers. Agricultural plant protection management is the collective product of a complex agricultural system, which encompasses treatment, marketing, industry and agricultural consultation as well as agricultural teaching institutions and relevant scientific disciplines. Successful management strategies for risk reduction in the context of hormonally active agrochemicals thus need to involve all actors within this system. The paper proposes a strategy that promotes participation by enabling learning processes among these actors.
文摘One of the traditional games played among the Yoruba people of South Western Nigeria utilizes the seeds ofDioclea reflexa. An investigation into the current status of the game was conducted to determine the extent to which it is still played. Although results indicate that the game is still being played in the rural areas, it also shows that it is steeply decreasing in popularity. About 6.6% of respondents interviewed have never heard of the game, while about 77% have played, or still play the game. Overall 17% of all respondents, or 22% of those who have ever played, still play the game. About 26% of respondents are optimistic about the game surviving their generation. The decline in popularity is attributable to decreasing proportion of youths in rural areas due to rural-urban migration, emergence of computer games, and scarcity of the seeds. Cultivation of D. reflexa plant for the game, food and medicinal purposes is recommended.
文摘The solubilities of two β-agonists, cimaterol and mabuterol, in supercritical carbon dioxide (SF-CO2) were measured by a recirculating method at temperatures of 40℃ and 60℃ and pressures between 9 MPa to 49 MPa.The compounds exhibit very limited solubilities in the range of 10^-5 to 10^-7 (mole fraction). Cimaterol has a higher solubility than that of mabuterol. The experimental data of solubility were correlated by four density-based models.The correlation accuracy highly depends on the system investigated, which is mainly determined by the density ranges and temperature.
文摘Allelopathy importance and its application under field conditions are reviewed. Recent achievements in the field of plant protection are mainly considered and presented. Natural chemicals of potential use as pesticides, commercialized natural products of pesticidal properties are included. Reported plants of pest control properties, their targeted agricultural pests, formulations, methods of application and activity under field conditions are presented. Allelopathic plant species and implications on their use in the field, positive and negative impacts on cultivated crop species and agricultural pests are discussed. Some research difficulties and experimental methodology problems are mentioned. Prospects of allelopathy as a future strategy for pest management, development of eco-friendly biopesticides and importance for sustainable agriculture and recent developments in allelopathy research are discussed.
