为研究苘麻叶总鞣质的提取工艺及抗氧化活性,本研究通过单因素试验和响应面试验优化苘麻叶总鞣质的提取工艺,同时采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除法和铁离...为研究苘麻叶总鞣质的提取工艺及抗氧化活性,本研究通过单因素试验和响应面试验优化苘麻叶总鞣质的提取工艺,同时采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除法和铁离子还原/抗氧化能力(FRAP)测定法等评价苘麻叶总多酚、不被吸附的多酚和总鞣质的体外抗氧化活性。结果表明,苘麻叶总鞣质的最佳提取工艺为:丙酮浓度70%、液料比15.25 m L/g、提取时间20 min;在此工艺条件下,8月份、9月份和10月份采收的苘麻叶总鞣质的含量分别为(1.41±0.05)‰、(1.77±0.03)‰和(1.49±0.03)‰;苘麻叶总鞣质具有较好的体外抗氧化活性。本研究得出了苘麻叶总鞣质的高效提取工艺,且提取的总鞣质具有较好的抗氧化活性。展开更多
A plant＇s capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plan...A plant＇s capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plant species＇ capacity to compensate for defoliation is related to how resource availability affects a plant＇s growth trajectory. Growth rate trajectory is defined as the percent change in relative growth rate or the slope of a plant＇s relative growth rate. 90 Abutilon theophrasti, a common weed species, in cultivated fields of corn and soybean, grew in a greenhouse for 70 d under three nitrogen （N） fertilization treatments. ＂Unfertilized＂ plants were not fertilized, ＂bulk＂ fertilized plants received 0.6 g N on day 15 and ＂exponential＂ fertilized plants received a total of 0.6 g N supplied at an exponential rate of 10% per day with a starting concentration of 0.02 g N on day 15. On day 25, 15 plants in each N treatment had 75% of total leaf area removed. Biomass and reproductive compensation were determined after 50 d and 70 d of growth. Results showed that bulk plants had the greatest absolute growth, but also the greatest decline in growth rates and the least capacity for compensation. Unfertilized plants had the lowest absolute growth, but declines in growth rates were similar to bulk plants with only a slightly greater compensatory capacity. Exponential plants had intermediate absolute growth, but the least decline in growth rates and the greatest capacity for compensation. This experiment indicates that a plant＇s growth rate trajectory, and not high or low relative growth rates or N availability per se, can be used to predict a weedy plant＇s capacity to compensate for herbivory, and has implications for biocontrol of weedy species.展开更多
文摘为研究苘麻叶总鞣质的提取工艺及抗氧化活性,本研究通过单因素试验和响应面试验优化苘麻叶总鞣质的提取工艺,同时采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除法和铁离子还原/抗氧化能力(FRAP)测定法等评价苘麻叶总多酚、不被吸附的多酚和总鞣质的体外抗氧化活性。结果表明,苘麻叶总鞣质的最佳提取工艺为:丙酮浓度70%、液料比15.25 m L/g、提取时间20 min;在此工艺条件下,8月份、9月份和10月份采收的苘麻叶总鞣质的含量分别为(1.41±0.05)‰、(1.77±0.03)‰和(1.49±0.03)‰;苘麻叶总鞣质具有较好的体外抗氧化活性。本研究得出了苘麻叶总鞣质的高效提取工艺,且提取的总鞣质具有较好的抗氧化活性。
文摘A plant＇s capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plant species＇ capacity to compensate for defoliation is related to how resource availability affects a plant＇s growth trajectory. Growth rate trajectory is defined as the percent change in relative growth rate or the slope of a plant＇s relative growth rate. 90 Abutilon theophrasti, a common weed species, in cultivated fields of corn and soybean, grew in a greenhouse for 70 d under three nitrogen （N） fertilization treatments. ＂Unfertilized＂ plants were not fertilized, ＂bulk＂ fertilized plants received 0.6 g N on day 15 and ＂exponential＂ fertilized plants received a total of 0.6 g N supplied at an exponential rate of 10% per day with a starting concentration of 0.02 g N on day 15. On day 25, 15 plants in each N treatment had 75% of total leaf area removed. Biomass and reproductive compensation were determined after 50 d and 70 d of growth. Results showed that bulk plants had the greatest absolute growth, but also the greatest decline in growth rates and the least capacity for compensation. Unfertilized plants had the lowest absolute growth, but declines in growth rates were similar to bulk plants with only a slightly greater compensatory capacity. Exponential plants had intermediate absolute growth, but the least decline in growth rates and the greatest capacity for compensation. This experiment indicates that a plant＇s growth rate trajectory, and not high or low relative growth rates or N availability per se, can be used to predict a weedy plant＇s capacity to compensate for herbivory, and has implications for biocontrol of weedy species.
