Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 ...Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.Methods:A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years.The relative biomasses of C4 plants(PC4),C4 annuals(PA4),and C4 perennials(PP4)were calculated.Structural equation modeling was used to analyze the drivers of changes in PA4 and PP4.Results:At the regional scale,PA4 on average was 11%(±19%,SD)and PP4 was 13%(±19%,SD).Spatially,C4 annuals dominated the C4 communities within an east–west belt region along 44°N and tended to spread toward northern latitudes(about 0.5°)and higher altitudes in the east mountainous areas.The abundance of C4 annuals decreased,while that of C4 perennials increased.The patterns of C4 annuals and C4 perennials were mainly controlled by temperature,growing season precipitation,and dynamics between the two life forms.Conclusions:C4 annuals exhibited competitive advantages in normal and wet years,while C4 perennials had competitive advantages in dry years.Grazing as a main human disturbance increased C4 annuals,but had no significant effect on C4 perennials.展开更多
Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environme...Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environmental losses, including water quality degradation, loss of biodiversity and natural habitats, reduced climate mitigation as well as social and health risks. This study evaluated the effect of different land use types on nutrient stock distribution across varying soil depths in Busega wetland. The soil samples were collected in three different land uses (annually cultivated areas, perennially cultivated areas, and the undisturbed wetland area) at three different depths (0 - 10 cm, 10 - 20 cm, and 20 - 30 cm) in 2021. The soil samples were analyzed for physicochemical soil properties including soil texture and nitrogen, phosphorus, calcium, and potassium concentrations. The interaction between land use type and soil depth did not have a significant effect on nutrient distribution. However, our results showed that the main effects of land use type and soil depth influenced nutrient stock distribution across the wetland. Higher nutrient concentrations were observed under perennial cropping system than in both annual cropping system and the undisturbed wetland area. Soils under perennial cropping systems had the highest soil organic matter (1.45%), calcium (2.06 Cmol/Kg) and potassium (0.091 Cmol/Kg) levels. Higher soil organic matter (1.40%), nitrogen (0.22%), calcium (1.74 Cmol/Kg), and potassium (0.07 Cmol/Kg) were found at the mid-soil depth of 10 - 20 cm. Our results show substantial nutrient changes due to agricultural activities in the Busega wetland, suggesting further research is urgently needed to determine if these changes have adverse effects on biodiversity and water quality of the wetland and nearby water resources.展开更多
Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolera...Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.展开更多
In artificially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg...In artificially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg·kg^(-1),respectively)to simulate compound pollution conditions.The results showed that the concentrations of heavy metals,trans-port factors,and bioconcentration factors in mixed planting of ryegrass decreased compared with those in mono-culture.Regardless of whether heavy metal pollution was introduced,mixed planting increased the aboveground and underground biomasses of ryegrass.The different mixed planting treatments had no significant impact on the chlorophyll concentration of ryegrass.The mowing time,mixed planting treatment,and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances,and there were some interactions.The mixed planting treatment did not significantly affect glutathione concentration,cysteine concentration,or nonprotein thiol.Mixed planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon,nitrogen,and phosphorus.These results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal pollution.However,it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.展开更多
An analytic hierarchy process(AHP)was employed to establish a landscape value evaluation model for 20 common species of perennial flowers in the flower border of Hefei City.With the overarching objective of determinin...An analytic hierarchy process(AHP)was employed to establish a landscape value evaluation model for 20 common species of perennial flowers in the flower border of Hefei City.With the overarching objective of determining the application value of the flower border,10 evaluation factors were identified and subsequently classified into 3 distinct grades.Grade I(L>2.5)was defined as perennial flower resources with the highest development and utilization value,including only one species of Salvia farinacea.Grade II(2.0≤L≤2.5)was defined as perennial flower varieties suitable for most areas,encompassing 9 species of plants,such asTaraxacummongolicum.Grade III(L<2.0)was defined as perennial flower varieties with low application value,encompassing 10 species of plants,such asRuellia brittoniana,but lacking the value of further popularization and application.Consequently,the proportion of their application in the flower border should be reduced.The evaluation results can serve as a theoretical foundation for the implementation of perennial flowers in urban flower borders.展开更多
Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegr...Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.展开更多
《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2...《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2010版采用推荐、评估、发展和评价分级(Grading of Recommendations,Assessment,Development and Evaluation,GRADE)工作组提出的透明的、系统化的方法修订了临床建议,以提高其实用价值。展开更多
基金supported by the DFG within the DFG research group 536(MAGIM)the National Natural Science Foundation of China(31630010 and 31320103916).
文摘Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.Methods:A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years.The relative biomasses of C4 plants(PC4),C4 annuals(PA4),and C4 perennials(PP4)were calculated.Structural equation modeling was used to analyze the drivers of changes in PA4 and PP4.Results:At the regional scale,PA4 on average was 11%(±19%,SD)and PP4 was 13%(±19%,SD).Spatially,C4 annuals dominated the C4 communities within an east–west belt region along 44°N and tended to spread toward northern latitudes(about 0.5°)and higher altitudes in the east mountainous areas.The abundance of C4 annuals decreased,while that of C4 perennials increased.The patterns of C4 annuals and C4 perennials were mainly controlled by temperature,growing season precipitation,and dynamics between the two life forms.Conclusions:C4 annuals exhibited competitive advantages in normal and wet years,while C4 perennials had competitive advantages in dry years.Grazing as a main human disturbance increased C4 annuals,but had no significant effect on C4 perennials.
文摘Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environmental losses, including water quality degradation, loss of biodiversity and natural habitats, reduced climate mitigation as well as social and health risks. This study evaluated the effect of different land use types on nutrient stock distribution across varying soil depths in Busega wetland. The soil samples were collected in three different land uses (annually cultivated areas, perennially cultivated areas, and the undisturbed wetland area) at three different depths (0 - 10 cm, 10 - 20 cm, and 20 - 30 cm) in 2021. The soil samples were analyzed for physicochemical soil properties including soil texture and nitrogen, phosphorus, calcium, and potassium concentrations. The interaction between land use type and soil depth did not have a significant effect on nutrient distribution. However, our results showed that the main effects of land use type and soil depth influenced nutrient stock distribution across the wetland. Higher nutrient concentrations were observed under perennial cropping system than in both annual cropping system and the undisturbed wetland area. Soils under perennial cropping systems had the highest soil organic matter (1.45%), calcium (2.06 Cmol/Kg) and potassium (0.091 Cmol/Kg) levels. Higher soil organic matter (1.40%), nitrogen (0.22%), calcium (1.74 Cmol/Kg), and potassium (0.07 Cmol/Kg) were found at the mid-soil depth of 10 - 20 cm. Our results show substantial nutrient changes due to agricultural activities in the Busega wetland, suggesting further research is urgently needed to determine if these changes have adverse effects on biodiversity and water quality of the wetland and nearby water resources.
基金supported by funding from the National Natural Science Foundation of China(32060593 and 32060474)the Yunnan Provincial Science and Technology Department+4 种基金China(202101AT070021 and 202101AS070001)the Yunnan Provincial Department of Education Science Research Fund ProjectChina(2023J0006)the Graduate Innovation Project of Yunnan UniversityChina(KC-22223012 and ZC-22222760)。
文摘Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.
基金funded through projects of the National Key Research and Development Program of China(2023YFD1301401)Cheng Wei received the grant.Ministry of Science and Technology of the People’s Republic of China(https://www.most.gov.cn/index.html,accessed on 19/03/2024)+1 种基金And the Guizhou Provincial Science and Technology Projects(QKHPTRC-CXTD[2022]1011)Chao Chen received the grant.Guizhou Provincial Department of Science and Technology(https://kjt.guizhou.gov.cn/,accessed on 19/03/2024).
文摘In artificially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg·kg^(-1),respectively)to simulate compound pollution conditions.The results showed that the concentrations of heavy metals,trans-port factors,and bioconcentration factors in mixed planting of ryegrass decreased compared with those in mono-culture.Regardless of whether heavy metal pollution was introduced,mixed planting increased the aboveground and underground biomasses of ryegrass.The different mixed planting treatments had no significant impact on the chlorophyll concentration of ryegrass.The mowing time,mixed planting treatment,and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances,and there were some interactions.The mixed planting treatment did not significantly affect glutathione concentration,cysteine concentration,or nonprotein thiol.Mixed planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon,nitrogen,and phosphorus.These results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal pollution.However,it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.
基金Sponsored by Landscape Value Evaluation of Perennial Flower Border Application for Open Field Cultivation in Hefei City(S202212216134)Natural Science Key Research Program for Colleges and Universities in Anhui Province(2023AH051816)Anhui General Teaching Research Project(2022jyxm665).
文摘An analytic hierarchy process(AHP)was employed to establish a landscape value evaluation model for 20 common species of perennial flowers in the flower border of Hefei City.With the overarching objective of determining the application value of the flower border,10 evaluation factors were identified and subsequently classified into 3 distinct grades.Grade I(L>2.5)was defined as perennial flower resources with the highest development and utilization value,including only one species of Salvia farinacea.Grade II(2.0≤L≤2.5)was defined as perennial flower varieties suitable for most areas,encompassing 9 species of plants,such asTaraxacummongolicum.Grade III(L<2.0)was defined as perennial flower varieties with low application value,encompassing 10 species of plants,such asRuellia brittoniana,but lacking the value of further popularization and application.Consequently,the proportion of their application in the flower border should be reduced.The evaluation results can serve as a theoretical foundation for the implementation of perennial flowers in urban flower borders.
基金Supported by National Natural Science Foundation of China(30471274)~~
文摘Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.
文摘《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2010版采用推荐、评估、发展和评价分级(Grading of Recommendations,Assessment,Development and Evaluation,GRADE)工作组提出的透明的、系统化的方法修订了临床建议,以提高其实用价值。
