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Plant growth-promoting properties and anti-fungal activity of endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta in arid lands
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作者 ZHAO Mengqi SU Huan +5 位作者 HUANG Yin Rashidin ABDUGHENI MA Jinbiao GAO Jiangtao GUO Fei LI Li 《Journal of Arid Land》 SCIE CSCD 2023年第11期1405-1420,共16页
Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathoge... Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathogenic fungal mycelia.In this study,an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species,Thymus altaicus and Salvia deserta,using a series of screening media.Plant samples of Thymus altaicus and Salvia deserta were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region,China,in July 2021.Additionally,the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi(Fusarium oxysporum,Fulvia fulva,Alternaria solani,and Valsa mali)were determined through the plate confrontation method.A total of 80 endophytic bacterial strains were isolated from Thymus altaicus,while a total of 60 endophytic bacterial strains were isolated from Salvia deserta.The endophytic bacterial strains from both Thymus altaicus and Salvia deserta exhibited plant growth-promoting properties.Specifically,the strains of Bacillus sp.TR002,Bacillus sp.TR005,Microbacterium sp.TSB5,and Rhodococcus sp.TR013 demonstrated strong cellulase-producing activity,siderophore-producing activity,phosphate solubilization activity,and nitrogen-fixing activity,respectively.Out of 140 endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta,104 strains displayed anti-fungal activity against Fulvia fulva,Alternaria solani,Fusarium oxysporum,and Valsa mali.Furthermore,the strains of Bacillus sp.TR005,Bacillus sp.TS003,and Bacillus sp.TSB7 exhibited robust inhibition rates against all the four pathogenic fungi.In conclusion,the endophytic bacterial strains from Thymus altaicus and Salvia deserta possess both plant growth-promoting and anti-fungal properties,making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases. 展开更多
关键词 endophytic bacteria Thymus altaicus Salvia deserta pathogenic fungi plant growth-promoting properties anti-fungal activity
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Plant growth-promoting rhizobacteria(PGPR)and its mechanisms against plant diseases for sustainable agriculture and better productivity 被引量:2
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作者 PRANAB DUTTA GOMATHY MUTHUKRISHNAN +12 位作者 SABARINATHAN KUTALINGAM GOPALASUBRAMAIAM RAJAKUMAR DHARMARAJ ANANTHI KARUPPAIAH KARTHIBA LOGANATHAN KALAISELVI PERIYASAMY MARUMUGAM PILLAI GK UPAMANYA SARODEE BORUAH LIPA DEB ARTI KUMARI MADHUSMITA MAHANTA PUNABATI HEISNAM AK MISHRA 《BIOCELL》 SCIE 2022年第8期1843-1859,共17页
Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with t... Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration. 展开更多
关键词 plant growth-promoting rhizobacteria BIOCONTROL plant diseases PGPR mechanisms Sustainable agriculture
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Synergistic combination of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria modulates morpho-physiological characteristics and soil structure in Nitraria tangutorum bobr.Under saline soil conditions 被引量:2
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作者 Jing Pan CuiHua Huang +5 位作者 Fei Peng Tao Wang Jie Liao ShaoXiu Ma QuanGang You Xian Xue 《Research in Cold and Arid Regions》 CSCD 2022年第6期393-402,共10页
Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activ... Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR. 展开更多
关键词 Nitraria tangutorum Bobr. Arbuscular mycorrhizal fungi plant growth-promoting rhizobacteria Morphological development Photosynthesis physiology Soil structure
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Effect of Plant Growth-Promoting Rhizobacteria at Various Nitrogen Rates on Corn Growth 被引量:1
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作者 Yaru Lin Dexter B. Watts +2 位作者 Joseph W. Kloepper Anthony O. Adesemoye Yucheng Feng 《Agricultural Sciences》 2019年第12期1542-1565,共24页
Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture,... Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha&#8722;1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies. 展开更多
关键词 plant growth-promoting RHIZOBACTERIA CORN GROWTH NITROGEN FERTILIZATION Root Morphology NITROGEN Use Efficiency
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Potential seed germination-enhancing plant growth-promoting rhizobacteria for restoration of Pinus chiapensis ecosystems
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作者 Cristina Domínguez-Castillo Julia María Alatorre-Cruz +5 位作者 Dolores Castañeda-Antonio Jose Antonio Munive Xianwu Guo Jesús Francisco López-Olguín Luis Ernesto Fuentes-Ramírez Ricardo Carreño-López 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第5期2143-2153,共11页
Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise ... Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development. 展开更多
关键词 Pinus chiapensis plant growth-promoting rhizobacteria Dyella Luteimonas ENTEROBACTER
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Application Progress of Plant Growth-promoting Bacteria in Crops
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作者 Ting ZHANG Ling ZHANG +3 位作者 Yingying ZHANG Ran ZHENG Fuxing XIANG Jie LI 《Agricultural Biotechnology》 CAS 2022年第6期18-21,38,共5页
Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecolo... Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecological agriculture,new biological fertilizers such as microbial inocula and microbial fertilizers based on PGPBs have been gradually applied in crop planting.Based on plant growth promotion and disease control,the application progress of PGPBs in crops from the aspects of growth promotion mechanism,growth promotion effect,resistance to biological and abiotic stresses were discussed,aiming to provide reference for the relevant research and application of PGPBs in crops. 展开更多
关键词 plant growth-promoting bacteria(PGPBs) CROPS Application progress
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MORPHOLOGICAL MODEL FOR RHEOLOGICAL PROPERTIES OF PLANT CELL SUSPENSION CULTURE SYSTEM
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作者 吴兆亮 元英进 +1 位作者 邢允 胡宗定 《Transactions of Tianjin University》 EI CAS 1999年第2期61-64,共4页
This paper puts forward a physical and mathematical model for the rheological properties of a plant cell suspension culture system.The model can explain why the system is pseudoplastic satisfactorily,thus the rheologi... This paper puts forward a physical and mathematical model for the rheological properties of a plant cell suspension culture system.The model can explain why the system is pseudoplastic satisfactorily,thus the rheological properties of the system as the effect of the flow behavior index on plant cell concentration are interpreted correctly and the mechanism of the rheological properties of the system is further understood.Therefore the model can be applied in the technological design and optimum conditions of the system and the reformation,evaluation and scale up of reactors. 展开更多
关键词 morphological model rheological property plant cell suspension culture pseudoplastic fluid
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Effects of warming and clipping on plant and soil properties of an alpine meadow in the Qinghai-Tibetan Plateau, China 被引量:15
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作者 Man Hou XU Fei PENG +4 位作者 Quan Gang YOU Jian GUO Xia Fei TIAN Min LIU Xian XUE 《Journal of Arid Land》 SCIE CSCD 2015年第2期189-204,共16页
Climate warming and livestock grazing are known to have great influences on alpine ecosystems like those of the Qinghai-Tibetan Plateau (QTP) in China. However, it is lacking of studies on the effects of warming and... Climate warming and livestock grazing are known to have great influences on alpine ecosystems like those of the Qinghai-Tibetan Plateau (QTP) in China. However, it is lacking of studies on the effects of warming and grazing on plant and soil properties in these alpine ecosystems. In this study, we reported the related research from manipulative experiment in 2010-2012 in the QTP. The aim of this study was to investigate the individual and combined effects of warming and clipping on plant and soil properties in the alpine meadow ecosystem. Infrared radiators were used to simulate climate warming starting in July 2010, while clipping was performed once in Octo- ber 2011 to simulate the local livestock grazing. The experiment was designed as a randomized block consisting of five replications and four treatments: control (CK), warming (W), clipping (C) and warming+clipping combination (WC). The plant and soil properties were investigated in the growing season of the alpine meadow in 2012. The results showed that W and WC treatments significantly decreased relative humidity at 20-cm height above ground as well as significantly increases air temperature at the same height, surface temperature, and soil temperature at the depth of 0-30 cm. However, the C treatment did not significantly decrease soil moisture and soil temperature at the depth of 0-60 cm. Relative to CK, vegetation height and species number increased significantly in W and WC treatment, respectively, while vegetation aboveground biomass decreased significantly in C treatment in the early growing season. However, vegetation cover, species diversity, belowground biomass and soil properties at the depth of 0-30 cm did not differ significantly in W, C and WC treatments. Soil moisture increased at the depth of 40-100 cm in W and WC treatments, while belowground biomass, soil activated carbon, organic carbon and total nitrogen increased in the 30-50 cm soil layer in W, C and WC treatments. Although the initial responses of plant and soil properties to experimental warming and clipping were slow and weak, the drought induced by the down- ward shift of soil moisture in the upper soil layers may induce plant belowground biomass to transfer to the deeper soil layers. This movement would modify the distributions of soil activated carbon, organic carbon and total nitrogen However, long-term data collection is needed to further explain this interesting phenomenon. 展开更多
关键词 simulated warming OVERGRAZING soil property plant property alpine meadow ecosystem Qinghai-Tibetan Plateau
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Influence of tourist disturbance on soil properties, plant communities, and surface water quality in the Tianchi scenic area of Xinjiang, China 被引量:3
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作者 WEN Bin ZHANG Xiaolei +2 位作者 YANG Zhaoping XIONG Heigang QIU Yang 《Journal of Arid Land》 SCIE CSCD 2016年第2期304-313,共10页
The impact of tourist disturbance on the environment has become a focal issue of environmental science, ecology, and travel management studies. To assess the influence of tourist disturbance on soils and plants in the... The impact of tourist disturbance on the environment has become a focal issue of environmental science, ecology, and travel management studies. To assess the influence of tourist disturbance on soils and plants in the Tianchi scenic area of Xinjiang, China, we compared soil properties and plant community characteristics at 0, 5, 10, and 20 m from the tourist trail within areas at three different altitudes, where the intensities of tourist disturbance are distinct. Surface water quality was also studied at three different levels relative to the Tianchi Lake. The results showed that tourist disturbance significantly increased soil pH within 10 m from the trail and soil bulk density on the edge of the trail, but significantly reduced soil organic matter and total nitrogen contents within 5 m from the trail. The number of tree seedlings on the edge of the trail and the shrub coverage and height of herbaceous plants within 5 m from the trail significantly decreased due to tourist disturbance. Changes in herbaceous plant diversity differed by soil zones. In the high altitude region, tourist disturbance led to a remarkable increase in the herbaceous plant diversity on the edge of the trail, while in the low altitude region, tourist disturbance had a low impact on the diversity of herbaceous plants. In addition, tourist activities polluted the surface water, significantly reducing water quality. Thus, current tourist activities have a significant negative impact on the ecological environment in the Tianchi scenic area. 展开更多
关键词 tourist disturbance soil properties plant communities water quality Tianchi scenic area
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Influence of soil microorganisms and physicochemical properties on plant diversity in an arid desert of Western China 被引量:5
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作者 Xiaodong Yang Yanxin Long +5 位作者 Binoy Sarkar Yan Li Guanghui Lv Arshad Ali Jianjun Yang Yue-E.Cao 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第6期2645-2659,共15页
Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity.However,the operational mechanisms and which factor is the most influential manipulato... Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity.However,the operational mechanisms and which factor is the most influential manipulator remain poorly understood.In this study,we examine the collaborative influences of soil physicochemical properties(i.e.,soil water,soil organic matter(SOM),salinity,total phosphorus and nitrogen,pH,soil bulk density and fine root biomass)and soil microorganisms(fungi and bacteria)on plant diversity across two types of tree patches dominated by big and small trees(big trees:height≥7 m and DBH≥60 cm;small trees:height≤4.5 m and DBH≤20 cm)in an arid desert region.Tree patch is consists of a single tree or group of trees and their accompanying shrubs and herbs.It was hypothesized that soil physicochemical properties and microorganisms affect plant diversity but their influence differ.The results show that plant and soil microbial diversity increased with increasing distances from big trees.SOM,salinity,fine root biomass,soil water,total phosphorus and total nitrogen contents decreased with increasing distance from big trees,while pH and soil bulk density did not change.Plant and soil microbial diversity were higher in areas close to big trees compared with small trees,whereas soil physicochemical properties were opposite.The average contribution of soil physicochemical properties(12.2%-13.5%)to plant diversity was higher than microbial diversity(4.8%-6.7%).Salinity had the largest negative affect on plant diversity(24.7%-27.4%).This study suggests that soil fungi constrain plant diversity while bacteria improve it in tree patches.Soil physicochemical properties are the most important factor modulating plant diversity in arid desert tree patches. 展开更多
关键词 Arid ecosystem Soil microbial diversity Soil physicochemical properties plant diversity Soil salinity
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Effect of SiO_2/B_2O_3 Ratio on the Property of Borosilicate Glass Applied in Parabolic Trough Solar Power Plant 被引量:1
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作者 田英良 SHAO Yanli +2 位作者 陆平 CHENG Jinshu LIU Wencai 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第1期51-55,共5页
This work aimed to analyze the glass material used for sealing the end of a thermal collector in a parabolic trough solar power plant. Based on matched sealing requirements and application performance of glass and Kov... This work aimed to analyze the glass material used for sealing the end of a thermal collector in a parabolic trough solar power plant. Based on matched sealing requirements and application performance of glass and Kovar alloy 4J29, one borosilicate glass material (GD480S), whose expansion coefficient was similar to that of Kovar alloy 4J29, was studied. Moreover, the effect of the ratio of SiO2 to B203 on the glass properties was explored in detail by Fourier transform infrared spectroscopy. As the SiO2 to B203 ratio in the glass increased from 4.18 to 5.77, the expansion coefficient showed a decreasing trend from 4.95×10-6/℃ to 4.55℃ 10-6/℃. In addition, the water resistance performance improved, enabling the glass material to seal well with the alloy for application in a trough solar power plant. Thus, the increase in the SiO2 to B2O3 ratio made the glass structure more compact and improved the glass performance to meet the requirements of an industrial tubular receiver. 展开更多
关键词 trough solar power plant borosilicate glass component and property FTIR
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Leguminosae plants play a key role in affecting soil physical-chemical and biological properties during grassland succession after farmland abandonment in the Loess Plateau,China 被引量:1
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作者 SUN Lin YU Zhouchang +5 位作者 TIAN Xingfang ZHANG Ying SHI Jiayi FU Rong LIANG Yujie ZHANG Wei 《Journal of Arid Land》 SCIE CSCD 2023年第9期1107-1128,共22页
Leguminosae are an important part of terrestrial ecosystems and play a key role in promoting soil nutrient cycling and improving soil properties.However,plant composition and species diversity change rapidly during th... Leguminosae are an important part of terrestrial ecosystems and play a key role in promoting soil nutrient cycling and improving soil properties.However,plant composition and species diversity change rapidly during the process of succession,the effect of leguminosae on soil physical-chemical and biological properties is still unclear.This study investigated the changes in the composition of plant community,vegetation characteristics,soil physical-chemical properties,and soil biological properties on five former farmlands in China,which had been abandoned for 0,5,10,18,and 30 a.Results showed that,with successional time,plant community developed from annual plants to perennial plants,the importance of Leguminosae and Asteraceae significantly increased and decreased,respectively,and the importance of grass increased and then decreased,having a maximum value after 5 a of abandonment.Plant diversity indices increased with successional time,and vegetation coverage and above-and below-ground biomass increased significantly with successional time after 5 a of abandonment.Compared with farmland,30 a of abandonment significantly increased soil nutrient content,but total and available phosphorus decreased with successional time.Changes in plant community composition and vegetation characteristics not only change soil properties and improve soil physical-chemical properties,but also regulate soil biological activity,thus affecting soil nutrient cycling.Among these,Leguminosae have the greatest influence on soil properties,and their importance values and community composition are significantly correlated with soil properties.Therefore,this research provides more scientific guidance for selecting plant species to stabilize soil ecosystem of farmland to grassland in the Loess Plateau,China. 展开更多
关键词 secondary succession LEGUMINOSAE plant diversity plant community composition soil physical-chemical properties soil biological properties
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Influence of ginseng cultivation under larch plantations on plant diversity and soil properties in Liaoning Province,Northeast China 被引量:1
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作者 LIU Wei-wei LIU Mou-cheng +2 位作者 LI Wen-hua ZENG Fan-shun QU Yi 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1598-1608,共11页
Currently, transforming the mode of forest management and developing multiple forest management practices are actively encouraged in China. As one forest management type, ginseng cultivation under larch plantations ha... Currently, transforming the mode of forest management and developing multiple forest management practices are actively encouraged in China. As one forest management type, ginseng cultivation under larch plantations has been developed significantly in the east of Liaoning Province. However, research on the influence of the ecological environment for this mode of production is still deficient. Based on this, our study compares the plant diversity and soil properties in the ginseng cultivation under larch plantations(LG) with larch plantations(LP) and natural secondary forests(SF). First, we randomly selected three plots for each of the three stand types which have similar stand characteristics; then, we carried out a plant diversity survey and soil sampling in each of the nine plots. The results show that no significant difference was found in plant diversity between LG and LP, but theevenness of herbs was significantly lower in LG than LP. No obvious changes in soil physical properties were found in LG, but a significant decrease in most of the soil nutrient content was presented in LG. Furthermore, we found a correlation between plant diversity(H') and soil properties in the three kinds of stand types, especially between herbaceous plant diversity and soil properties. We conclude that ginseng cultivation under larch plantations has no obvious effect on plant diversity, except the herbaceous evenness. Soil fertility can be depleted significantly in LG, but physical structures are not affected. Moreover, maintaining the diversity of herbaceous plants and controlling the density of ginseng cultivation in LG by farmers are important for the ecological environment. Based on this study and its good comprehensive benefits and with the support of policy, we think this forest management type should be promoted moderately in the region. 展开更多
关键词 Forest management Ginseng cultivation Larch plantations Secondary forests plant diversity Soil properties Changbai Mountain
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Relationship between stand characteristics and soil properties of two typical forest plantations in the mountainous area of Western Sichuan, China
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作者 YANG Hao MIAO Ning +4 位作者 LI Shao-cai MA Rui LIAO Zi-yan WANG Wei-ping SUN Hai-long 《Journal of Mountain Science》 SCIE CSCD 2019年第8期1816-1832,共17页
There is uncertainty and limited knowledge regarding stand characteristics and soil properties of middle-aged pure forest plantations in the mountainous area of Western Sichuan. Plantation forests are almost exclusive... There is uncertainty and limited knowledge regarding stand characteristics and soil properties of middle-aged pure forest plantations in the mountainous area of Western Sichuan. Plantation forests are almost exclusively planted as monocultures in the Pengzhou forest farm in the western mountainous area of Sichuan Province. This study aimed to assess the spatial and ecological characteristics of middle-aged Cunninghamia lanceolata(Lamb.) Hook. and Cryptomeria fortunei Hooibr. in the Pengzhou forest farm. The relationships and differences between stand growth characteristics and forest soil composition were assessed on the two forests planted simultaneously within the same area and exposed to the same environmental conditions. Cr. fortunei grew sparse, and slower than Cun. lanceolata. Principal component analysis indicated that the soil properties in the Cr. fortunei plantation were better than those in the Cun. lanceolata plantation. Redundancy analysis revealed that the differences in stand structure were affected significantly by the total nitrogen content and pH value. Thus, we propose that Cr. fortunei is planted for priority consideration in the subtropical high mountain area. Further, tending operations and application of fertilizers need to be conducted in Cun. lanceolata forests. Based on theoretical and experimental data, the present study explains why local farmers are more willing to plant Cr. fortunei, and thus provides a useful theoretical reference for the development of sustainable plantations in the future. 展开更多
关键词 planted forest STAND structure SOIL properties Cunninghamia lanceolata CRYPTOMERIA fortunei PIONEER tree
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Structural Characteristics and Mechanical Properties of Rock Mass in the Field of Tianwan Nuclear Power Plant, China
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作者 周念清 唐益群 +1 位作者 邓永华 赵在立 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第4期512-517,524,共7页
The structural characteristics and mechanical properties of the rock mass are important parts of the feasibility study on the nuclear power engineering field. In this study, by means of in situ investigation and stati... The structural characteristics and mechanical properties of the rock mass are important parts of the feasibility study on the nuclear power engineering field. In this study, by means of in situ investigation and statistics, the structural plane and joint fissure features of the rock mass were analyzed and discussed at different plots and different depth scopes in the Tianwan Nuclear Power engineering field, the rock mass integrality and its weathered degree were evaluated respectively, and especially, the unfavorable geological phenomena of strongly-weathered cystid existing in the field were studied. According to the results of indoor rock mechanical tests, in combination with drilling, the shallow seismic prospecting, sonic logging and point load tests, the statistical results of physical and mechanical indices of rocks at key plots of the field were analyzed, and the design parameters of the field were calculated. It provided scientific basis for the foundation design of the nuclear power plant. 展开更多
关键词 Tianwan Nuclear Power plant structural PLANE joint FISSURE weathered degree ROCK mass INTEGRALITY MECHANICAL property
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Rheological Properties of Five Plant Gums
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作者 Quanquan Miao Huaishi Jiang +4 位作者 Lei Gao Yujie Cheng Jiachao Xu Xiaoting Fu Xin Gao 《American Journal of Analytical Chemistry》 2018年第4期210-223,共14页
The rheological properties of five gum solutions (Gum Shiraz, Karaya Gum, Ghatti Gum, Arabic Gum and Gum Tragacanth) have been examined. The five mucilage solutions exhibited non-Newtonian, shear-thinning with thixotr... The rheological properties of five gum solutions (Gum Shiraz, Karaya Gum, Ghatti Gum, Arabic Gum and Gum Tragacanth) have been examined. The five mucilage solutions exhibited non-Newtonian, shear-thinning with thixotropy at higher concentrations (0.5% - 1%, m/v). According to the change of viscosity with increasing temperature, all five gums could be defined as three types: gum tragacanth and gum shiraz have a good temperature stability;karaya gum is affected by temperature obviously;the remaining two gums have a general stability. The viscosity of mucilage solutions (Arabic Gum, Ghatti Gum and Karaya Gum) had an apparent dependence on temperature. The parameter n of Shiraz Gum is the minimum, which means it has the best flow properties. The flow activation energy of karaya gum is 2.683 kcal which is the highest than other gums so that it has a great influence on temperature. The gum solutions’ viscosity had different sensitive degree over tested pH range (pH 2 - 10). Shiraz gum and arabic gum possessed better acid-proof and alkali-proof respectively. The addition of salts (NaCl and CaCl2) led to the reduction of viscosity, which was more sensitive to Ca2+ than to Na+. Both storage modulus G’ and loss modulus G” of all five gums had a dependence on temperature and frequency. These results are potentially useful for the application in the field of food processing. 展开更多
关键词 plant GUMS RHEOLOGICAL Properties VISCOSITY Behavior Storage MODULUS LOSS MODULUS
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<i>In Vitro</i>Antibacterial, Antifungal and Other Medical Properties of Endangered Medicinal Plant Seeds
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作者 Mohammed A. Almalki 《Pharmacology & Pharmacy》 2017年第5期189-204,共16页
The risk created by infectious microorganisms to humans attracted the development of common medicine. To find an alternative source, medicinal plants with diverse metabolites play an important role in curing the disea... The risk created by infectious microorganisms to humans attracted the development of common medicine. To find an alternative source, medicinal plants with diverse metabolites play an important role in curing the diseases and human disorders caused by microbial pathogens. Medicinal plants namely, Citrullus colocynthis, Hyoscyamus muticus, Ocimum basilicum, Amaranthus lividus, Salvia aegyptiaca and Ruta chalepensis are commonly used as a traditional medicine in Gulf countries. The present study aimed to investigate the antibacterial, antifungal and antioxidant potential of the organic crude extracts obtained from the seeds. Besides, the possible antimicrobial mechanisms of the extracts were evaluated by determining the enzyme activities. The antibacterial and antifungal activities of the crude extracts were evaluated by the broth micro dilution method and the effect of the extracts on the pathogens were determined by quantifying the alkaline phosphatase (ALP), lactate dehydrogenase (LDH) enzymes and intracellular protein leakage. Besides, the antioxidant properties were determined using hydroxyl radical scavenging assay, DPPH radical scavenging assay, reducing power assay and superoxide radical scavenging assay. Results indicated that the extracts of C. colocynthis showed promising activity against all the tested pathogens, especially the MIC values were ranged from 100 to 150 μg/ml for Gram positive bacteria and 100 to 250 μg/ml for Gram negative bacteria respectively. The MIC values of H. muticus, O. basilicum and R. chalepensis against the fungal pathogens were ranged from 100 to 500 μg/mL respectively. The ALP activity was higher in extract treated Klebsiella pneumoniae compared with control, whereas the LDH and protein concentrations for Escherichia coli and Staphylococcus aureus were comparatively higher. Furthermore, all the studied seed extract showed good antioxidant activities. In conclusion, the studied plant seed extracts documented good antimicrobial and antioxidant activities. Therefore, the medicinal plants would be the excellent source for natural antioxidant and antibacterial agents for medical and applications. 展开更多
关键词 MEDICINAL plants ANTIMICROBIAL ACTIVITIES ANTIFUNGAL ACTIVITIES Mechanism of ANTIMICROBIAL Action Antioxidant Properties
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Effect of dry-wet cycles on dynamic properties and microstructures of sandstone:Experiments and modelling 被引量:1
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作者 Hai Pu Qingyu Yi +3 位作者 Andrey P.Jivkov Zhengfu Bian Weiqiang Chen Jiangyu Wu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第5期655-679,共25页
Underground pumped storage power plant(UPSP)is an innovative concept for space recycling of abandoned mines.Its realization requires better understanding of the dynamic performance and durability of reservoir rock.Thi... Underground pumped storage power plant(UPSP)is an innovative concept for space recycling of abandoned mines.Its realization requires better understanding of the dynamic performance and durability of reservoir rock.This paper conducted ultrasonic detection,split Hopkinson pressure bar(SHPB)impact,mercury intrusion porosimetry(MIP),and backscatter electron observation(BSE)tests to investigate the dynamical behaviour and microstructure of sandstone with cyclical dry-wet damage.A coupling FEM-DEM model was constructed for reappearing mesoscopic structure damage.The results show that dry-wet cycles decrease the dynamic compressive strength(DCS)with a maximum reduction of 39.40%,the elastic limit strength is reduced from 41.75 to 25.62 MPa.The sieved fragments obtain the highest crack growth rate during the 23rd dry-wet cycle with a predictable life of 25 cycles for each rock particle.The pore fractal features of the macropores and micro-meso pores show great differences between the early and late cycles,which verifies the computational statistics analysis of particle deterioration.The numerical results show that the failure patterns are governed by the strain in pre-peak stage and the shear cracks are dominant.The dry-wet cycles reduce the energy transfer efficiency and lead to the discretization of force chain and crack fields. 展开更多
关键词 Underground pumped storage power plant Dry-wet cycles Split Hopkinson pressure bar Macro and micro properties FEM-DEM coupling model Damage characterization
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Effects of Different Planting Years on Physicochemical Properties and Enzyme Activities in Soil of Rice-Cherry Tomato Rotation
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作者 Xiao Deng Chunyuan Wu +2 位作者 Yi Li Huadong Tan Jiancheng Su 《Open Journal of Ecology》 2023年第6期334-344,共11页
Crop rotation periodicity has always been one of the research focuses currently. In this study, the physicochemical properties, nutrient contents and enzyme activities were investigated in soils from rice-cherry tomat... Crop rotation periodicity has always been one of the research focuses currently. In this study, the physicochemical properties, nutrient contents and enzyme activities were investigated in soils from rice-cherry tomato rotation for one year (1a), three years (3a), five years (5a), seven years (7a) and ten years (10a), respectively. The major objective was to analyze the optimal rotation years of rice-cherry tomato from soil perspective, so as to provide theoretical basis for effectively avoiding continuous cropping obstacles of cherry tomato via studying the response characteristics of soil physicochemical properties, nutrient contents and enzyme activities to planting years of rice-cherry tomato rotation system. The results were as follows: 1) Soil pH value was increased year by year during 1a to 5a, reached the highest value 5.32 at 5a. However, soil acidity was sharply enhanced during 7a to 10a (P P •kg<sup>-1</sup> at 5a. 3) The content of soil available phosphorus was increased year by year with increasing of crop rotation years, and increased by 110% to 173% during 3a to 10a (P P P < 0.05). In conclusion, long-term single rotation pattern of rice-cherry tomato would aggravate soil acidification, prompt soil nutrient imbalance and reduce soil enzyme activity. 5a to 7a would be the appropriate rotation period for rice-cherry tomato, or else it would reduce soil quality, resulting in a new continuous cropping obstacle of cherry tomato. 展开更多
关键词 Rice-Cherry Tomato Rotation planting Years SOIL Physicochemical Properties Enzyme Activity
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A review on medicinal plants in north region of India: traditional use in Vedic culture and their pharmacological properties culture and their pharmacological properties
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作者 Sonal Verma Sunita Arya Robina Aman 《TMR Integrative Medicine》 2022年第26期1-11,共11页
Medicinal plants are widely employed for healing reasons in many native systems of medicine and are becoming increasingly popular in modern culture as alternatives to manufactured medications.The current study is a de... Medicinal plants are widely employed for healing reasons in many native systems of medicine and are becoming increasingly popular in modern culture as alternatives to manufactured medications.The current study is a descriptive review in which papers were searched from several databases such as Springer,Wiley,Taylor and Francis,Elsevier,etc.It is time to rethink the way we improve our immune systems and seek evidence-based treatments that best use plant-based medicines to benefit patients.Bioactive principles are responsible for medicinal plants’therapeutic actions and give limitless chances for novel drug leads because of their exceptional availability of chemical variety.The chemical characteristics of the included bioactive components determine whether standardized plant extracts are beneficial or poisonous.A summary of research papers on plants such as garlic,aloe vera,stinging nettle,saffron,clove,holy basil,turmeric,cinnamon,giloe,liquorice,and aloe vera having bioactive molecules and cures for several diseases such as influenza virus,gastrointestinal cancer neurodegenerative disorder,cardiovascular diseases,urinary disorder,diabetes,skin disease,obesity,and respiratory disorder is included in this overview. 展开更多
关键词 AYURVEDA medicinal plants bioactive SAFFRON GARLIC aloe vera stinging nettle pharmacological properties
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