Experimental results show that, all the sample of seasonal-temperature combinations, the effective component content is highest in November to collect leaves in the 25%; drying, and the strongest antioxidant activity....Experimental results show that, all the sample of seasonal-temperature combinations, the effective component content is highest in November to collect leaves in the 25%; drying, and the strongest antioxidant activity. The results of this study will provide theoretical basis for the preparation process of pomegranate leaf tea. Results of the correlation between antioxidant activity and the effective components show that the antioxidant activity of pomegranate leaves is closely related to polyphenol content, in particular had significant correlation with the content of tannin polyphenols, flavonoids, and ellagic acid content had no significant correlation.展开更多
A new pterosaur Archaeoistiodactylus linglongtaensis gen. et sp. nov. is erected based on an incomplete skeleton with a partial skull and lower jaw. The new taxon is characterized by circular tooth sockets of anterior...A new pterosaur Archaeoistiodactylus linglongtaensis gen. et sp. nov. is erected based on an incomplete skeleton with a partial skull and lower jaw. The new taxon is characterized by circular tooth sockets of anterior mandibular teeth,the anterior teeth of the upper jaw bearing posteriorly directed crowns,a relatively short metacarpus,and wing phalanges 2 and 3 and the tibia subequal in length. It possesses some plesiomorphic characters such as short metacarpals and circular tooth sockets. The pointed jaw tip present in the new taxon indicates that the expanded jaw tips of later istiodactylids are a derived character state,and the new taxon represents the first istiodactylus-like pterosaur found from the pre-Late Jurassic deposits,which provides a key role in our understanding the origin and evolution of the known istiodactylid pterosaurs. Archaeoistiodactylus is regarded as the ancestor form of the known istiodactylid pterosaur.展开更多
Plants produce secondary chemicals that may vary along with latitude due to changing abiotic and biotic stress gradients and local environmental conditions.Teasing apart the individual and combined effects of these di...Plants produce secondary chemicals that may vary along with latitude due to changing abiotic and biotic stress gradients and local environmental conditions.Teasing apart the individual and combined effects of these different abiotic,such as soil nutrients,and biotic factors,such as soil biota and herbivores,on secondary chemicals is critical for understanding plant responses to changing environments.We conducted an experiment at different latitudes in China,using tallow tree(Triadica sebifera)seedlings sourced from a population at 31°N.These seedlings were cultivated in gardens located at low,middle and high latitudes,with either local soil or soil from the original seed collection site(origin soil).The seedlings were exposed to natural levels of aboveground herbivores or had them excluded.Plant secondary chemicals(both foliar and root),aboveground herbivores and soil characteristics were measured.Results showed that most leaf and root secondary metabolites depended on the interaction of the experimental site and soil type.Leaf and root phenolic and tannin concentrations were higher at the middle latitude site,especially in the origin soil.Root and foliar flavonoid concentrations increased when aboveground herbivores were excluded.Microbial communities depended strongly on soil treatment.The different responses of tannins versus flavonoids suggest that these two chemical classes differ in their responses to the varying abiotic and biotic factors in these sites along latitudes.Taken together,our results emphasize the importance of considering the interactive effects of local environmental conditions,soil properties and herbivory in regulating plant chemical defenses.展开更多
文摘Experimental results show that, all the sample of seasonal-temperature combinations, the effective component content is highest in November to collect leaves in the 25%; drying, and the strongest antioxidant activity. The results of this study will provide theoretical basis for the preparation process of pomegranate leaf tea. Results of the correlation between antioxidant activity and the effective components show that the antioxidant activity of pomegranate leaves is closely related to polyphenol content, in particular had significant correlation with the content of tannin polyphenols, flavonoids, and ellagic acid content had no significant correlation.
基金supported by grants from the Natural Science Foundation of China (40872017,90914003)the 973 Project (2006CB701405)+1 种基金the Basic Outlay of Scientific Research Work from the Ministry of Science and Technology (J1003 J0703)
文摘A new pterosaur Archaeoistiodactylus linglongtaensis gen. et sp. nov. is erected based on an incomplete skeleton with a partial skull and lower jaw. The new taxon is characterized by circular tooth sockets of anterior mandibular teeth,the anterior teeth of the upper jaw bearing posteriorly directed crowns,a relatively short metacarpus,and wing phalanges 2 and 3 and the tibia subequal in length. It possesses some plesiomorphic characters such as short metacarpals and circular tooth sockets. The pointed jaw tip present in the new taxon indicates that the expanded jaw tips of later istiodactylids are a derived character state,and the new taxon represents the first istiodactylus-like pterosaur found from the pre-Late Jurassic deposits,which provides a key role in our understanding the origin and evolution of the known istiodactylid pterosaurs. Archaeoistiodactylus is regarded as the ancestor form of the known istiodactylid pterosaur.
基金supported by the National Natural Science Foundation of China(32101351)the Natural Science Foundation of Hunan Province(2022JJ40867)the Research Foundation of Education Bureau of Hunan Province(21B0265)to Li Xiao.
文摘Plants produce secondary chemicals that may vary along with latitude due to changing abiotic and biotic stress gradients and local environmental conditions.Teasing apart the individual and combined effects of these different abiotic,such as soil nutrients,and biotic factors,such as soil biota and herbivores,on secondary chemicals is critical for understanding plant responses to changing environments.We conducted an experiment at different latitudes in China,using tallow tree(Triadica sebifera)seedlings sourced from a population at 31°N.These seedlings were cultivated in gardens located at low,middle and high latitudes,with either local soil or soil from the original seed collection site(origin soil).The seedlings were exposed to natural levels of aboveground herbivores or had them excluded.Plant secondary chemicals(both foliar and root),aboveground herbivores and soil characteristics were measured.Results showed that most leaf and root secondary metabolites depended on the interaction of the experimental site and soil type.Leaf and root phenolic and tannin concentrations were higher at the middle latitude site,especially in the origin soil.Root and foliar flavonoid concentrations increased when aboveground herbivores were excluded.Microbial communities depended strongly on soil treatment.The different responses of tannins versus flavonoids suggest that these two chemical classes differ in their responses to the varying abiotic and biotic factors in these sites along latitudes.Taken together,our results emphasize the importance of considering the interactive effects of local environmental conditions,soil properties and herbivory in regulating plant chemical defenses.
