Antimicrobial potential of quinoa seeds from six diverse seeds, grown in three distinctive geo-graphical zones of Chile, was correlated with their total phenolic content (TPC), total flavonoid content (TFC) and total ...Antimicrobial potential of quinoa seeds from six diverse seeds, grown in three distinctive geo-graphical zones of Chile, was correlated with their total phenolic content (TPC), total flavonoid content (TFC) and total saponin content (TSC). The six seeds were Ancovinto, Cancosa, Cahuil, Faro, Regalona and Villarrica. A significant influence of quinoa source on chemical composition of seeds was observed. Extracts of all quinoa samples showed antimicrobial activity in the range of 8.3 - 14.8 mm inhibition zone for E. coli and 8.5 - 15.0 mm inhibition zone for S. aureus. Cancosa seeds had the highest antimicrobial action. The TPC and TFC ranged from 3.71 to 16.55 mg GA/100 g d.m. and 7.77 to 14.37 mg QE/100 g d.m., respectively. TSC varied from 1.78 to 3.08 g/100 g d.m. A cor-relation between TFC and antimicrobial activity was found. In conclusion, the six types of quinoa seeds were identified as potential sources of antioxidant compounds and antimicrobial activity.展开更多
In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Norther...In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Northern and Southern Patagonian Icefields (NPI and SPI, respectively). Calculations have shown a generalized thinning and withdrawal, which greatly contributes to the increase in sea level attributed to the ice melt from non-polar glaciers. However, these icefields are surrounded by many small icecaps, which have yet to be studied in detail. A precise estimation of the volume of ice located in these mountain chains could provide new information with respect to this area's exact contribution to the increase in sea level. Thus, this study presents an inventory of relatively small Northern Patagonian glaciers in the surrounding of the three summits: Mount Queulat, and the Macá and Hudson volcanoes. The study used remote sensing techniques in a GIS environment to determine the margins, surface areas, thickness changes and hypsometry for the glaciated zones. Landsat images from different dates were analyzed using standard band ratio and screen delineation techniques. Additionally, digital elevation models from different dates were compared using map algebra, calculating thickness changes. Based on the results, we propose that there are important volumetric changes in the glaciers studied, which could be explained by precipitation trends in a general context, and an influence of the glaciers' sizes in some local response. Therefore, we suggest the exact contribution of the Patagonia to the increase in sea level corresponds to a regional pattern rather than just the behavior of a single ice field.展开更多
Different crop varieties can respond in different ways to the climatic variations at local scale. Thus, in order to maximize the yield for a determined crop, the response of different varieties submitted to local clim...Different crop varieties can respond in different ways to the climatic variations at local scale. Thus, in order to maximize the yield for a determined crop, the response of different varieties submitted to local climatic conditions should be assessed. The main goal of this study was to evaluate the ecophysiological responses of two varieties of Quinoa (PRP and BO78) submitted to different conditions of thermal amplitude. We performed two experiments in both greenhouse and in 3 sites on experimental-field where were evaluated survival, photochemical efficiency, plant growth and dry biomass in both varieties and compared them with the mean of the thermal conditions recorded during the last 16 years in the Coquimbo Region, Chile. Overall, individuals of BO78 showed higher performance in the sites with lower thermal amplitude than those of PRP. By contrast, in sites with higher thermal amplitude individuals of PRP showed better survival, physiological performance and biomass and therefore higher performance. Our results suggest that while BO78 showed an ecotypic strategy, the PRP showed a plastic strategy to maintain higher performance in sites with moderate and high climatic variability. We consider that under an increase in desertification, semi-arid areas would be available for stress tolerant crops like Quinoa, but the success for the food security in these regions may depend upon the variety used.展开更多
文摘Antimicrobial potential of quinoa seeds from six diverse seeds, grown in three distinctive geo-graphical zones of Chile, was correlated with their total phenolic content (TPC), total flavonoid content (TFC) and total saponin content (TSC). The six seeds were Ancovinto, Cancosa, Cahuil, Faro, Regalona and Villarrica. A significant influence of quinoa source on chemical composition of seeds was observed. Extracts of all quinoa samples showed antimicrobial activity in the range of 8.3 - 14.8 mm inhibition zone for E. coli and 8.5 - 15.0 mm inhibition zone for S. aureus. Cancosa seeds had the highest antimicrobial action. The TPC and TFC ranged from 3.71 to 16.55 mg GA/100 g d.m. and 7.77 to 14.37 mg QE/100 g d.m., respectively. TSC varied from 1.78 to 3.08 g/100 g d.m. A cor-relation between TFC and antimicrobial activity was found. In conclusion, the six types of quinoa seeds were identified as potential sources of antioxidant compounds and antimicrobial activity.
基金Dirección de Investigación, Universidad de Concepción, Project number 208.603.009-1.0, financed some parts of this study
文摘In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Northern and Southern Patagonian Icefields (NPI and SPI, respectively). Calculations have shown a generalized thinning and withdrawal, which greatly contributes to the increase in sea level attributed to the ice melt from non-polar glaciers. However, these icefields are surrounded by many small icecaps, which have yet to be studied in detail. A precise estimation of the volume of ice located in these mountain chains could provide new information with respect to this area's exact contribution to the increase in sea level. Thus, this study presents an inventory of relatively small Northern Patagonian glaciers in the surrounding of the three summits: Mount Queulat, and the Macá and Hudson volcanoes. The study used remote sensing techniques in a GIS environment to determine the margins, surface areas, thickness changes and hypsometry for the glaciated zones. Landsat images from different dates were analyzed using standard band ratio and screen delineation techniques. Additionally, digital elevation models from different dates were compared using map algebra, calculating thickness changes. Based on the results, we propose that there are important volumetric changes in the glaciers studied, which could be explained by precipitation trends in a general context, and an influence of the glaciers' sizes in some local response. Therefore, we suggest the exact contribution of the Patagonia to the increase in sea level corresponds to a regional pattern rather than just the behavior of a single ice field.
文摘Different crop varieties can respond in different ways to the climatic variations at local scale. Thus, in order to maximize the yield for a determined crop, the response of different varieties submitted to local climatic conditions should be assessed. The main goal of this study was to evaluate the ecophysiological responses of two varieties of Quinoa (PRP and BO78) submitted to different conditions of thermal amplitude. We performed two experiments in both greenhouse and in 3 sites on experimental-field where were evaluated survival, photochemical efficiency, plant growth and dry biomass in both varieties and compared them with the mean of the thermal conditions recorded during the last 16 years in the Coquimbo Region, Chile. Overall, individuals of BO78 showed higher performance in the sites with lower thermal amplitude than those of PRP. By contrast, in sites with higher thermal amplitude individuals of PRP showed better survival, physiological performance and biomass and therefore higher performance. Our results suggest that while BO78 showed an ecotypic strategy, the PRP showed a plastic strategy to maintain higher performance in sites with moderate and high climatic variability. We consider that under an increase in desertification, semi-arid areas would be available for stress tolerant crops like Quinoa, but the success for the food security in these regions may depend upon the variety used.