The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observ...The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observed for studying the photosynthetic adaptability of plants to the influences of stress conditions in alpine environment. Rfd _values, the vitality index, in leaves of K. humilis and P.viviparum grown at 3?980 m were higher than those at 3?200 m. The higher ratio of F v/F o and F v/F m in leaves of K. humilis and P.viviparum indicated that the rate of photosynthetic conversion of light energy increased at higher altitude. Ratios of F v/F o and F v/F m and Rfd _values in K.humilis were higher than that in P.viviparum grown at the same altitude. There were more irregular chloroplasts in leaves of both species grown at higher altitude. Many irregular chloroplasts such as swollen thylakoid, deformed chloroplast envelope, were observed in P.viviparum grown at 3?980 m, but few in K. humilis . These results were discussed in relation to the photosynthetic adaptability of alpine plants and the different adaptive competence between K.humilis and P.viviparum .展开更多
Phenotypic plasticity and/or pollinatormediated selection may be responsible for the changes in floral traits of plants when they are forced to live in new conditions. Although the two events could be independent, we ...Phenotypic plasticity and/or pollinatormediated selection may be responsible for the changes in floral traits of plants when they are forced to live in new conditions. Although the two events could be independent, we hypothesized that phenotypic plasticity in floral traits might help to coordinate plant-pollinator interactions and enhance plant reproductive success in changing habitats. To test this hypothesis, we investigated floral traits and pollination on three natural populations of a lousewort(Pedicularis siphonantha) ranging at different elevations, as well as two downward transplanted populations in Shangeri-La County and Deqin County, northwest Yunnan, China. The results indicated that floral traits, i.e. phenology, longevity,display size, corolla tube length and pollen production differed significantly among populations. Moreover,or the two transplanted populations, floral traits diverged from their original populations, but converged to their host populations. Although the phenotypic plasticity in floral traits might be a rapid response to abiotic factor such as warmer environment, the changes in floral traits were found to be well adapted to pollination environment of the host population. Compared with plants of their original habitats in higher elevation, the transplanted individuals advanced flowering time, shortened flower longevity, reduced floral display size and pollen production, received higher visiting frequency and yielded more seeds. These findings suggested that phenotypic plasticity of floral traits might help plants adjust their resource allocation strategy between preand post-pollination stages in response to harsh or temperate conditions, which might correspondingly meet a pollinator-poor or hyphen rich environment.This would be beneficial for the widely-distributed species to adapt to various environmental changes.展开更多
A phytochemical investigation on the aerial parts of Artemisia brachyloba led to the isolation of 13 compounds（1-13） for the first time, including eight lignans（1-8） and five flavonoids（9-13）. The structures of ...A phytochemical investigation on the aerial parts of Artemisia brachyloba led to the isolation of 13 compounds（1-13） for the first time, including eight lignans（1-8） and five flavonoids（9-13）. The structures of the isolated compounds were elucidated by analysis of the NMR spectroscopic data and comparison with the literature. The 1 H and 13 C NMR data of 1 were fully assigned for the first time by the 2 D NMR analysis. All the isolates were evaluated for their inhibitory effects on nitric oxide production in lipopolysaccharide-challenged BV-2 microglial cells.展开更多
文摘The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observed for studying the photosynthetic adaptability of plants to the influences of stress conditions in alpine environment. Rfd _values, the vitality index, in leaves of K. humilis and P.viviparum grown at 3?980 m were higher than those at 3?200 m. The higher ratio of F v/F o and F v/F m in leaves of K. humilis and P.viviparum indicated that the rate of photosynthetic conversion of light energy increased at higher altitude. Ratios of F v/F o and F v/F m and Rfd _values in K.humilis were higher than that in P.viviparum grown at the same altitude. There were more irregular chloroplasts in leaves of both species grown at higher altitude. Many irregular chloroplasts such as swollen thylakoid, deformed chloroplast envelope, were observed in P.viviparum grown at 3?980 m, but few in K. humilis . These results were discussed in relation to the photosynthetic adaptability of alpine plants and the different adaptive competence between K.humilis and P.viviparum .
基金supported by the National Natural Science Foundation of China (Grant No. 31370263 and 31770255)
文摘Phenotypic plasticity and/or pollinatormediated selection may be responsible for the changes in floral traits of plants when they are forced to live in new conditions. Although the two events could be independent, we hypothesized that phenotypic plasticity in floral traits might help to coordinate plant-pollinator interactions and enhance plant reproductive success in changing habitats. To test this hypothesis, we investigated floral traits and pollination on three natural populations of a lousewort(Pedicularis siphonantha) ranging at different elevations, as well as two downward transplanted populations in Shangeri-La County and Deqin County, northwest Yunnan, China. The results indicated that floral traits, i.e. phenology, longevity,display size, corolla tube length and pollen production differed significantly among populations. Moreover,or the two transplanted populations, floral traits diverged from their original populations, but converged to their host populations. Although the phenotypic plasticity in floral traits might be a rapid response to abiotic factor such as warmer environment, the changes in floral traits were found to be well adapted to pollination environment of the host population. Compared with plants of their original habitats in higher elevation, the transplanted individuals advanced flowering time, shortened flower longevity, reduced floral display size and pollen production, received higher visiting frequency and yielded more seeds. These findings suggested that phenotypic plasticity of floral traits might help plants adjust their resource allocation strategy between preand post-pollination stages in response to harsh or temperate conditions, which might correspondingly meet a pollinator-poor or hyphen rich environment.This would be beneficial for the widely-distributed species to adapt to various environmental changes.
基金National Natural Science Foundation of China(Grant No.81373294)National Key Technology R&D Program"New Drug Innovation"of China(Grant No.2018ZX09711001-008-003)
文摘A phytochemical investigation on the aerial parts of Artemisia brachyloba led to the isolation of 13 compounds（1-13） for the first time, including eight lignans（1-8） and five flavonoids（9-13）. The structures of the isolated compounds were elucidated by analysis of the NMR spectroscopic data and comparison with the literature. The 1 H and 13 C NMR data of 1 were fully assigned for the first time by the 2 D NMR analysis. All the isolates were evaluated for their inhibitory effects on nitric oxide production in lipopolysaccharide-challenged BV-2 microglial cells.
