Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive tu...Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.展开更多
Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper...Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper is to review the current state of knowledge on stable isotopes of carbon, oxygen, and hydrogen in the research of crop carbon and water relations, such as carbon isotope discrimination （△^13C） during carbon fixation process by photosynthesis, application of △^13C in crop water use efficiency （WUE） and breeding programs, oxygen isotope enrichment during leaf water transpiration, CO2 fixation by photosynthesis and release by respiration, application of hydrogen isotope composition （619） and oxygen isotope composition （6180） for determination of water source used by a crop, stable isotope coupling Keeling plot for investigating the carbon and water flux in ecosystem, energy and material cycle in SPAC and correlative integrative models on stable isotope. These aspects contain most of the stable isotope researches on crop carbon and water relations which have been widely explored internationally while less referred in China. Based on the reviewed literatures, some needs for future research are suggested.展开更多
While the need for understanding the effects of topographical factors on forest structure and function is well recognized,comprehensive studies are scarce.This study evaluates the effect of slope aspect and slope posi...While the need for understanding the effects of topographical factors on forest structure and function is well recognized,comprehensive studies are scarce.This study evaluates the effect of slope aspect and slope position on water relations and forest attributes across six forest types occurring between 400 m and 2600 m altitude in the Central Himalaya(27°-38°N).We found that predawn tree water potential and soil water potential were generally higher on moist north slope aspect(-0.78±0.05 MPa and-3.34±0.18 MPa,respectively)than dry south slope aspect(-0.82±0.18 MPa and-3.77±0.18 MPa,respectively).Across six different forests,these values were higher at hill base(-0.71±0.06 MPa and-2.77±0.19 MPa,tree predawn water potential and soil water potential,respectively)than other topographical positions.The favorable effect of north aspect and hill base was also observed in maintaining soil water and tree water potential during the dry season.Vegetation attributes,such as species richness,unique species and plant density were also generally higher on north slope and hill base than southern aspect and lowest at hill top.Across forest types,the hill base provided shelter to 46 unique species,compared to 16-18 at the other positions,thus emphasizing its importance as refugia for species to survive climate change induced perturbations.The favorable conditions of hill base position not only contribute to increase in alpha diversity,but also to extended species distributional range.展开更多
The integration offlexible electronics with plant science has generated various plant-wearable sensors,yet challenges persist in their application to real-world agriculture,particularly in high-throughput set-tings.Ov...The integration offlexible electronics with plant science has generated various plant-wearable sensors,yet challenges persist in their application to real-world agriculture,particularly in high-throughput set-tings.Overcoming the trade-off between sensing sensitivity and range,adapting sensors to a wide range of crop types,and bridging the gap between sensor measurements and biological understandings remain primary obstacles.Here,we introduce PlantRing,an innovative,nano-flexible sensing system designed to address these challenges.PlantRing employs bio-sourced carbonized silk georgette as the strain-sensing material,offering an exceptional detection limit(0.03%–0.17%strain,depending on sensor model),high stretchability(tensile strain up to 100%),and remarkable durability(season-long use).PlantRing effectively monitors plant growth and water status by measuring organ circumference dy-namics,performing reliably under harsh conditions,and adapting to a wide range of plant species.Applying PlantRing to study fruit cracking in tomato and watermelon has revealed a novel hydraulic mechanism characterized by genotype-specific excess sapflow within the plant to fruiting branches.Its high-throughput application has enabled large-scale quantification of stomatal sensitivity to soil drought—a long-standing aspiration in plant biology—facilitating the selection of drought-tolerant germ-plasm.Combining PlantRing with a soybean mutant has led to the discovery of a potential novel function of the circadian clock gene GmLNK2 in stomatal regulation.More practically,integrating PlantRing into feedback irrigation achieves simultaneous water conservation and quality improvement,signifying a paradigm shift from reliance on experience or environmental cues to plant-based feedback control.Collectively,PlantRing represents a groundbreaking tool poised to revolutionize botanical studies,agri-culture,and forestry.展开更多
Aims Changing climate and land use patterns make it increasingly important that the hydrology of catchments and ecosystems can be reliably characterized.The aim of this paper is to identify the biophysical factors tha...Aims Changing climate and land use patterns make it increasingly important that the hydrology of catchments and ecosystems can be reliably characterized.The aim of this paper is to identify the biophysical factors that determine the rates of water vapor loss from different types of vegetation,and to seek,from an array of currently available satelliteborne sensors,those that might be used to initialize and drive landscape-level hydrologic models.Important Findings Spatial variation in the mean heights,crowd widths,and leaf area indices(LAI)of plant communities are important structural variables that affect the hydrology of landscapes.Canopy stomatal conductance(G)imposes physiological limitation on transpiration by vegetation.The maximum value of G(Gmax)is closely linked to canopy photosynthetic capacity,which can be estimated via remote sensing of foliar chlorophyll or nitrogen contents.Gcan be modeled as a nonlinear multipliable function of:(i)leaf–air vapor pressure deficit,(ii)water potential gradient between soil and leaves,(iii)photosynthetically active radiation absorbed by the canopy,(iv)plant nutrition,(v)temperature and(vi)the CO_(2) concentration of the air.Periodic surveys with Light Detection and Ranging(LiDAR)and interferometric RADAR,along with high-resolution spectral coverage in the visible,near-infrared,and thermal infrared bands,provide,along with meteorological data gathered from weather satellites,the kind of information required to model seasonal and interannual variation in transpiration and evaporation from landscapes with diverse and dynamic vegetation.展开更多
Water resource is the important factor for sustainable development in Weigan River catchments in western China. Based on ecological hydrology principles, the coupling relation between water and salt is monitored and a...Water resource is the important factor for sustainable development in Weigan River catchments in western China. Based on ecological hydrology principles, the coupling relation between water and salt is monitored and analyzed. The water quality for irrigation in oasis ecosystem has a larger variable range in arid area, which depending on the input water resource and underground water mineralization degree and water chemical component on the catchments scale, the water and salt coupling is decided by the climate condition and soil feature and vegetation characteristics as well as human activity. Meanwhile, temporal and spatial change between water and salt is quite complicated. The environmental management should be paid attention to considering in irrigation area in the catchments.展开更多
A field study was conducted to evaluate the protozoan colonization patterns on artificial substrates in relation to organic pollution within a tropical harbour. The composition of protozoans and their succession rate...A field study was conducted to evaluate the protozoan colonization patterns on artificial substrates in relation to organic pollution within a tropical harbour. The composition of protozoans and their succession rates on artificial substrates(polyurethane foam units) were compared between two field stations(A and B), and their presence were considered with regards to the prevailing water quality conditions at the study sites. Altogether 44 genera of flagellates and ciliates were documented. The common genera of flagellates encountered included Monas, Polytoma, and Chromalina. Among the ciliates, the predominant genera were Tetrahymena, Vorticella, Lagynophyra, and Heloiphyra. These groups exhibited characteristic successional patterns in relation to ambient water quality. At Station A, located close to the sewage outfall, the water quality parameters included poor Secchi disc transparency(0.48m), dissolved oxygen of 1.93 mg/ml, salinity of 18 psu, and temperature 31.3 ℃. Here, the nanoflagellates( spumella ) colonized first, followed by microcilliate( Tetrahymena ) and sessile form( Vorticella ). Station B, located on the seaward side, was characterized by relatively less stressed environmental conditions with transparency 1.85m and dissolved oxygen value of 6 04 mg/ml. Salinity of 27.27 psu, and mean temperature of 30 ℃ were recorded at “B'. At this station, the nanoflagellate Polytoma was first documented to colonize on the substrates, followed by microcilliate( Lagynophrya ) and suctorid( Heliophyra ). These findings support the use of protozoans as indicator species for evaluating the hazards posed by organic pollution to natural estuarine communities.展开更多
The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was a...The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The de-crease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic wa-ter-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.展开更多
Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth...Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. Key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.展开更多
[Objective] The aim was to explore the effects of water stress on leaf water and chlorophyll fluorescence parameters of sugarcane seedling,as well as to provide basis for the study on sugarcane production and evaluati...[Objective] The aim was to explore the effects of water stress on leaf water and chlorophyll fluorescence parameters of sugarcane seedling,as well as to provide basis for the study on sugarcane production and evaluation. [Method] Seven different sugarcane varieties were studied at the seedling stage under drought stress,and the changes of leaf water and chlorophyll fluorescence parameters under stress conditions were detected. [Result] leaf water potential,leaf relative water content and soil relative water content showed a certain amount of internal relationship,the sugarcane varieties that had more tolerant to drought had higher utilization rate of soil water; the correlation analysis and factor analysis suggested that the survival rate at seedling stage under drought stress,Fv/Fm,leaf water potential and relative water content could be used as drought resistance evaluation indicators. [Conclusion] As a relatively independent influencing factor,water potential had dominating effect on drought resistance,and the reliability of Fv/Fm as drought resistance evaluation indicator had been verified.展开更多
Drought tolerance is complex in rice. Under drought stress, leaf water content trait can be used as a indicator for variety evaluation. In this study, ahybrid F2 population was constructed with drought-tolerant indica...Drought tolerance is complex in rice. Under drought stress, leaf water content trait can be used as a indicator for variety evaluation. In this study, ahybrid F2 population was constructed with drought-tolerant indica rice cultivar Luhan No.1 and japonica rice cultivar Nipponbare, to analyze QTLs related with relative water content in rice. According to the results, two QTLs were detected between markers 4-27M and 4-23M and between markers 6-3M and RM276 on chromosomes 4 and 6, with the contribution rate of 4.81% -6.43% to phenotypic variation.展开更多
By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechan...By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.展开更多
Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages, and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthopp...Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages, and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthoppcr (BPH), Nilaparvata lugens were determined in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research Institute (IRRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the increase of nitrogen content in rice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility to BPH damage on rice plants applied with nitrogen fertilizer.展开更多
Drought is the most common form of abiotic stress that reduces plant growth and productivity.It causes plant injuries through elevated production of reactive oxygen species(ROS).Potassium(K)is a vital plant nutrient t...Drought is the most common form of abiotic stress that reduces plant growth and productivity.It causes plant injuries through elevated production of reactive oxygen species(ROS).Potassium(K)is a vital plant nutrient that notably ameliorates the detrimental effect of drought stress in the plant.A pot experiment was conducted at the Laboratory of Plant Stress Responses,Faculty of Agriculture,Kagawa University,Japan,under controlled environment of green house to explore the role of K in mitigating drought severity in wheat(Triticum asevitum L.)seedlings.Three days after germination,seedlings were exposed to three water regimes viz.,100,50,and 20%field capacity(FC)for 21 days.Potassium was adjusted in Hoagland nutrient solution at 0,6 and 12 mM concentration and applied to pot instead of normal water.Results show that,water deficit stress notably reduced plant growth,biomass accumulation,leaf relative water content(RWC)along with reduced photosynthetic pigments.Increased amount of biochemical stress markers viz.,malondialdehyde(MDA),hydrogen peroxide(H_(2)O_(2)),methylglyoxal(MG),proline(Pro)as well as an impaired antioxidant defense system were observed in drought affected wheat plants.On the contrary,K supplementation resulted in improvement of biochemical and physiological parameters that worked behind in improving growth and development of the wheat plants.In addition,enzymes of ascorbateglutathione(AsA-GSH)cycle were also enhanced by supplemented K that accelerated the ROS detoxification process in plant.Although glyoxalse system did not performed well till MG was detoxified might following another short stepped pathways.Our results revealed that drought stressed plants showed better performances in terms of biochemical and physiological attributes,antioxidant defense and glyoxalase system,as well as ROS detoxification due to K supplementation with better performance at 12 mM K added in 50%FC growing condition.展开更多
Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the c...Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the current EPA drinking water standard and approximate dietary exposures of 4900μg in selenosis regions of China. Reviews of health significance of the elevated drinking water exposures to U. S. populations revealed elevated concentrations of selenium in urine and blood. A decrease in glutathione peroxidase activity in such instances was noted. However noticeable symptoms and signs seem absent in studies reviewed. A comparison of intake levels (diet or drinking water) to urinary excretion for residents of China and the U. S. produced a correlation coefficient, r = 0. 82 (P < 0. 01 ) for the three research studies available展开更多
Understanding of biomass and water allocation in plant populations will provide useful information on their growth pattern and resource allocation dynamics. By direct measurement, the biomass and water content partiti...Understanding of biomass and water allocation in plant populations will provide useful information on their growth pattern and resource allocation dynamics. By direct measurement, the biomass and water content partitioning were compared at the aboveground, belowground and whole-plant levels for artificial Caragana korshinskii populations between 6- and 25-year-old sites in desert steppe, northern China. The biomass was mainly allocated to third-srade branches at the aboveground level, and to firstand second-grade roots at the belowground level, and to aboveground parts at the whole-plant vegetative level. Those plant parts mentioned above became the major component of biomass pool of these shrub populations. Biomass pattern changed significantly at aboveground and/or whole-plant levels （P 〈0.05）, but not at belowground level （P 〉0.05） at 25-year-old site in comparison to 6-year-old site. Also, the water relations between dif- ferent plant parts changed considerably at all three levels from 6- to 25-year-old sites. These results imply that biomass pattern and relative water content of plant parts are correlated with the process of plantation development. The ratio of belowground to aboveground, though below 1, increased from 6- to 25-year-old site. These results suggest that these shrub populations can adjust biomass partition and relative water content of different compartments to alter their ecological adaptive strategies during stand development in desertified regions.展开更多
We study the feature of media changes beneath the Zipingpu reservoir and discuss the process of permeation with the water level rise and fall of the reservoir from January 2005 to January 2008 from ambient noise cross...We study the feature of media changes beneath the Zipingpu reservoir and discuss the process of permeation with the water level rise and fall of the reservoir from January 2005 to January 2008 from ambient noise cross correlation by using continuous seismic data recorded by the stations of Zipingpu seismic network and YZP station. A moving-window cross-spectrum technique has been used to calculate the relative seismic velocity changes between station pairs. Results revealed an obvious relationship between relative seismic velocity, and the water level changes with a time delay that may be caused by permeation during three main impoundments and two large scale disemboguements. Impoundment generates a fast and large impact on the superficial layer, and the changes of seismic velocity is the result of increased pressure and permeation during the impoundment. At the first impoundment, the main effect factor is pressure. During the next two process of impoundment, permeation becomes the main effect factor, affecting the fault at a depth of about 8kin.展开更多
The marshes of southern Iraq are of great value due to their roles in the economy,environment,heritage,tourism,and agriculture.However,the region has witnessed remarkable transformations in land cover,influenced by hu...The marshes of southern Iraq are of great value due to their roles in the economy,environment,heritage,tourism,and agriculture.However,the region has witnessed remarkable transformations in land cover,influenced by human interventions and natural environmental factors.In this research,the Central Marshlands were selected for study and monitoring.These Marshes form the Mesopotamian Marshes,a vital part of the Tigris-Euphrates river system.This area 2 formerly covered an area of approximately 3,000 km and was once home to the lives of Marsh Arabs and their animals.The primary objective of this study was to compile a set of satellite images covering the same marshland region over several decades.The data used includes images captured by various Landsat missions:MSS(1975),TM(1983&1993),ETM+(2003),and the Operational Land Imager(OLI)from Landsat 8(2015).Satellite images were combined and pre-processed through steps such as layer stacking to create composite images from multiple bands.Several image classification methods were applied,and the classification results showed a significant and unprecedented increase in the percentage of water in the marsh,reaching 16%in 2003.This was combined with vegetation identification techniques,including the identification of vegetation boundaries to detect areas of dense vegetation.In addition,the relative depth of the water was measured to estimate marsh water levels,with the best result obtained in 2003.The normalized mean vegetation index(NDVI)calculated in this study had its best value in 1984 due to the spread of reeds and papyrus during this period.Papyrus is the raw material in the sugar industry,providing a significant economic boost.展开更多
Achieving global fruit demand can be realized through the application of agricultural technologies.However,it is crucial to first overcome the enormous agricultural challenges posed by the implementation of efficient ...Achieving global fruit demand can be realized through the application of agricultural technologies.However,it is crucial to first overcome the enormous agricultural challenges posed by the implementation of efficient irrigation technologies.To address the issues related to inadequate water supply and inefficient traditional fruit tree irrigation methods,we propose a cost-effective and efficient approach-the“439”field precision irrigation scheme.This scheme predicts four relative soil water content minimum thresholds(RSWCTs)and maximum(RSWCTe)thresholds[relative to the percentage of field capacity(FC)]for starting and ending irrigation.By exploring the relationship between RSWCTs,RSWCTeand fruit quality,we assessed the scheme's effectiveness.A practical case study was conducted on grape(Vitis vinifera L.,‘87-1')cultivated in a facility from 2019 to 2022 to evaluate the scheme's impact on irrigation management.The results indicate that maintaining70%-80%FC from germination stage(GS)to end bloom stage(EBS),70%-80%FC from EBS to veraison stage(VS),55%-70%FC from VS to maturation stage(MS),and 55%-65%FC from MS to deciduous stage(DS)improve single grain weight(SGW).Similarly,to improve total soluble solid content,60%-80%FC is suggested from GS to EBS,70%-80%FC from EBS to VS,60%-70%FC from VS to MS,and 60%-70%FC from MS to DS.To improve peel strength and fruit quality index(FQI),70%-80%FC is recommended from GS to EBS,60%-70%FC from EBS to VS,55%-65%FC from VS to MS,and 55%-70%FC from MS to DS.This management tool helps farmers optimize irrigation efficiency and increase profits by growing high-quality fruit.In summary,the implementation of the“439”field precision irrigation system,coupled with fruit quality analysis,holds promise for enhancing water efficiency in precision agriculture.展开更多
文摘Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.
基金supported by the National Basic Re-search Program of China (973 Program) (2005CB121103)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-406KSCX1-YW-09-05)
文摘Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper is to review the current state of knowledge on stable isotopes of carbon, oxygen, and hydrogen in the research of crop carbon and water relations, such as carbon isotope discrimination （△^13C） during carbon fixation process by photosynthesis, application of △^13C in crop water use efficiency （WUE） and breeding programs, oxygen isotope enrichment during leaf water transpiration, CO2 fixation by photosynthesis and release by respiration, application of hydrogen isotope composition （619） and oxygen isotope composition （6180） for determination of water source used by a crop, stable isotope coupling Keeling plot for investigating the carbon and water flux in ecosystem, energy and material cycle in SPAC and correlative integrative models on stable isotope. These aspects contain most of the stable isotope researches on crop carbon and water relations which have been widely explored internationally while less referred in China. Based on the reviewed literatures, some needs for future research are suggested.
基金Department of Botany,Dolphin(PG)Institute of Bio-medical and Natural SciencesDepartment of Botany,DSB Campus,Kumaun University for liberal supportDepartment of Forestry and Environmental Science,DSB Campus,Kumaun University for the liberal support。
文摘While the need for understanding the effects of topographical factors on forest structure and function is well recognized,comprehensive studies are scarce.This study evaluates the effect of slope aspect and slope position on water relations and forest attributes across six forest types occurring between 400 m and 2600 m altitude in the Central Himalaya(27°-38°N).We found that predawn tree water potential and soil water potential were generally higher on moist north slope aspect(-0.78±0.05 MPa and-3.34±0.18 MPa,respectively)than dry south slope aspect(-0.82±0.18 MPa and-3.77±0.18 MPa,respectively).Across six different forests,these values were higher at hill base(-0.71±0.06 MPa and-2.77±0.19 MPa,tree predawn water potential and soil water potential,respectively)than other topographical positions.The favorable effect of north aspect and hill base was also observed in maintaining soil water and tree water potential during the dry season.Vegetation attributes,such as species richness,unique species and plant density were also generally higher on north slope and hill base than southern aspect and lowest at hill top.Across forest types,the hill base provided shelter to 46 unique species,compared to 16-18 at the other positions,thus emphasizing its importance as refugia for species to survive climate change induced perturbations.The favorable conditions of hill base position not only contribute to increase in alpha diversity,but also to extended species distributional range.
基金the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02066-5,2021C02067-7)for their support。
文摘The integration offlexible electronics with plant science has generated various plant-wearable sensors,yet challenges persist in their application to real-world agriculture,particularly in high-throughput set-tings.Overcoming the trade-off between sensing sensitivity and range,adapting sensors to a wide range of crop types,and bridging the gap between sensor measurements and biological understandings remain primary obstacles.Here,we introduce PlantRing,an innovative,nano-flexible sensing system designed to address these challenges.PlantRing employs bio-sourced carbonized silk georgette as the strain-sensing material,offering an exceptional detection limit(0.03%–0.17%strain,depending on sensor model),high stretchability(tensile strain up to 100%),and remarkable durability(season-long use).PlantRing effectively monitors plant growth and water status by measuring organ circumference dy-namics,performing reliably under harsh conditions,and adapting to a wide range of plant species.Applying PlantRing to study fruit cracking in tomato and watermelon has revealed a novel hydraulic mechanism characterized by genotype-specific excess sapflow within the plant to fruiting branches.Its high-throughput application has enabled large-scale quantification of stomatal sensitivity to soil drought—a long-standing aspiration in plant biology—facilitating the selection of drought-tolerant germ-plasm.Combining PlantRing with a soybean mutant has led to the discovery of a potential novel function of the circadian clock gene GmLNK2 in stomatal regulation.More practically,integrating PlantRing into feedback irrigation achieves simultaneous water conservation and quality improvement,signifying a paradigm shift from reliance on experience or environmental cues to plant-based feedback control.Collectively,PlantRing represents a groundbreaking tool poised to revolutionize botanical studies,agri-culture,and forestry.
文摘Aims Changing climate and land use patterns make it increasingly important that the hydrology of catchments and ecosystems can be reliably characterized.The aim of this paper is to identify the biophysical factors that determine the rates of water vapor loss from different types of vegetation,and to seek,from an array of currently available satelliteborne sensors,those that might be used to initialize and drive landscape-level hydrologic models.Important Findings Spatial variation in the mean heights,crowd widths,and leaf area indices(LAI)of plant communities are important structural variables that affect the hydrology of landscapes.Canopy stomatal conductance(G)imposes physiological limitation on transpiration by vegetation.The maximum value of G(Gmax)is closely linked to canopy photosynthetic capacity,which can be estimated via remote sensing of foliar chlorophyll or nitrogen contents.Gcan be modeled as a nonlinear multipliable function of:(i)leaf–air vapor pressure deficit,(ii)water potential gradient between soil and leaves,(iii)photosynthetically active radiation absorbed by the canopy,(iv)plant nutrition,(v)temperature and(vi)the CO_(2) concentration of the air.Periodic surveys with Light Detection and Ranging(LiDAR)and interferometric RADAR,along with high-resolution spectral coverage in the visible,near-infrared,and thermal infrared bands,provide,along with meteorological data gathered from weather satellites,the kind of information required to model seasonal and interannual variation in transpiration and evaporation from landscapes with diverse and dynamic vegetation.
文摘Water resource is the important factor for sustainable development in Weigan River catchments in western China. Based on ecological hydrology principles, the coupling relation between water and salt is monitored and analyzed. The water quality for irrigation in oasis ecosystem has a larger variable range in arid area, which depending on the input water resource and underground water mineralization degree and water chemical component on the catchments scale, the water and salt coupling is decided by the climate condition and soil feature and vegetation characteristics as well as human activity. Meanwhile, temporal and spatial change between water and salt is quite complicated. The environmental management should be paid attention to considering in irrigation area in the catchments.
文摘A field study was conducted to evaluate the protozoan colonization patterns on artificial substrates in relation to organic pollution within a tropical harbour. The composition of protozoans and their succession rates on artificial substrates(polyurethane foam units) were compared between two field stations(A and B), and their presence were considered with regards to the prevailing water quality conditions at the study sites. Altogether 44 genera of flagellates and ciliates were documented. The common genera of flagellates encountered included Monas, Polytoma, and Chromalina. Among the ciliates, the predominant genera were Tetrahymena, Vorticella, Lagynophyra, and Heloiphyra. These groups exhibited characteristic successional patterns in relation to ambient water quality. At Station A, located close to the sewage outfall, the water quality parameters included poor Secchi disc transparency(0.48m), dissolved oxygen of 1.93 mg/ml, salinity of 18 psu, and temperature 31.3 ℃. Here, the nanoflagellates( spumella ) colonized first, followed by microcilliate( Tetrahymena ) and sessile form( Vorticella ). Station B, located on the seaward side, was characterized by relatively less stressed environmental conditions with transparency 1.85m and dissolved oxygen value of 6 04 mg/ml. Salinity of 27.27 psu, and mean temperature of 30 ℃ were recorded at “B'. At this station, the nanoflagellate Polytoma was first documented to colonize on the substrates, followed by microcilliate( Lagynophrya ) and suctorid( Heliophyra ). These findings support the use of protozoans as indicator species for evaluating the hazards posed by organic pollution to natural estuarine communities.
基金Innovation Research Pro-ject of Chinese Academy of Sciences (KZCX1-10-03), National Natural Sciences Foundation of China (90102003), and West Development Technol-ogy Project (2001BA901A42).
文摘The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The de-crease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic wa-ter-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.
基金supported by the National Natural Science Foundation of China (No. 41471189)the Youth Science and Technology New Star Foundation of Shaanxi Province, China (No. 2013KJXX-09)+1 种基金the CAS "Light of West China" Programthe Youth Innovation Promotion Association CAS
文摘Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. Key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.
基金Supported by Key Projects in the National Science &Technology Pillar Program (2007BAD30B05)Key Project of Science and Tech-nology Department of Guangxi Province of China (0782004-5)the Program for Postgraduates Research Innovattion in GX. Univer-sity (105930903049)~~
文摘[Objective] The aim was to explore the effects of water stress on leaf water and chlorophyll fluorescence parameters of sugarcane seedling,as well as to provide basis for the study on sugarcane production and evaluation. [Method] Seven different sugarcane varieties were studied at the seedling stage under drought stress,and the changes of leaf water and chlorophyll fluorescence parameters under stress conditions were detected. [Result] leaf water potential,leaf relative water content and soil relative water content showed a certain amount of internal relationship,the sugarcane varieties that had more tolerant to drought had higher utilization rate of soil water; the correlation analysis and factor analysis suggested that the survival rate at seedling stage under drought stress,Fv/Fm,leaf water potential and relative water content could be used as drought resistance evaluation indicators. [Conclusion] As a relatively independent influencing factor,water potential had dominating effect on drought resistance,and the reliability of Fv/Fm as drought resistance evaluation indicator had been verified.
基金Supported by National "863" Project of China(2014AA10A603)Youth Innovation Fund of President of Anhui Academy of Agricultural Sciences(14B0114)Open Project of State Key Laboratory of Crop Genetic Improvement of Huazhong Agricultural University~~
文摘Drought tolerance is complex in rice. Under drought stress, leaf water content trait can be used as a indicator for variety evaluation. In this study, ahybrid F2 population was constructed with drought-tolerant indica rice cultivar Luhan No.1 and japonica rice cultivar Nipponbare, to analyze QTLs related with relative water content in rice. According to the results, two QTLs were detected between markers 4-27M and 4-23M and between markers 6-3M and RM276 on chromosomes 4 and 6, with the contribution rate of 4.81% -6.43% to phenotypic variation.
基金Supported by Science and Technology Innovation Project of Ji'nan City "Identification of Stress-resistant Malus sieversii Germplasm Resources and Screening of Stressresistance Functional Genes"(201401125)~~
文摘By pot experiment under artificially simulated water stress conditions, soluble protein content, MDA content and SOD, POD, CAT and APX activities in Malus sieversfi leaves were determined to reveal the response mechanism of M. sieversii to changes of relative soil water content. According to the results, with the decrease of relative soil water content, MDA content in M. sieversii leaves increased by mem- brane lipid peroxidation. Cells resist water stress-induced membrane lipid peroxidation and clear the increased reactive oxygen species by improving soluble protein content and SOD, POD, CAT and APX activities. However, various enzymes were involved in the response to water stress under different moisture conditions. In addition, the results indicated that M. sieversii had a good adaptability to higher relative soil water contents.
文摘Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages, and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthoppcr (BPH), Nilaparvata lugens were determined in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research Institute (IRRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the increase of nitrogen content in rice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility to BPH damage on rice plants applied with nitrogen fertilizer.
文摘Drought is the most common form of abiotic stress that reduces plant growth and productivity.It causes plant injuries through elevated production of reactive oxygen species(ROS).Potassium(K)is a vital plant nutrient that notably ameliorates the detrimental effect of drought stress in the plant.A pot experiment was conducted at the Laboratory of Plant Stress Responses,Faculty of Agriculture,Kagawa University,Japan,under controlled environment of green house to explore the role of K in mitigating drought severity in wheat(Triticum asevitum L.)seedlings.Three days after germination,seedlings were exposed to three water regimes viz.,100,50,and 20%field capacity(FC)for 21 days.Potassium was adjusted in Hoagland nutrient solution at 0,6 and 12 mM concentration and applied to pot instead of normal water.Results show that,water deficit stress notably reduced plant growth,biomass accumulation,leaf relative water content(RWC)along with reduced photosynthetic pigments.Increased amount of biochemical stress markers viz.,malondialdehyde(MDA),hydrogen peroxide(H_(2)O_(2)),methylglyoxal(MG),proline(Pro)as well as an impaired antioxidant defense system were observed in drought affected wheat plants.On the contrary,K supplementation resulted in improvement of biochemical and physiological parameters that worked behind in improving growth and development of the wheat plants.In addition,enzymes of ascorbateglutathione(AsA-GSH)cycle were also enhanced by supplemented K that accelerated the ROS detoxification process in plant.Although glyoxalse system did not performed well till MG was detoxified might following another short stepped pathways.Our results revealed that drought stressed plants showed better performances in terms of biochemical and physiological attributes,antioxidant defense and glyoxalase system,as well as ROS detoxification due to K supplementation with better performance at 12 mM K added in 50%FC growing condition.
文摘Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the current EPA drinking water standard and approximate dietary exposures of 4900μg in selenosis regions of China. Reviews of health significance of the elevated drinking water exposures to U. S. populations revealed elevated concentrations of selenium in urine and blood. A decrease in glutathione peroxidase activity in such instances was noted. However noticeable symptoms and signs seem absent in studies reviewed. A comparison of intake levels (diet or drinking water) to urinary excretion for residents of China and the U. S. produced a correlation coefficient, r = 0. 82 (P < 0. 01 ) for the three research studies available
基金supported by the National Natural Science Foundation of China(No.41101050)the National Science and Technology Support Program(2010BAC07B03) of Chinathe Projects of the National Basic Research Program of China(No.2009CB421303)
文摘Understanding of biomass and water allocation in plant populations will provide useful information on their growth pattern and resource allocation dynamics. By direct measurement, the biomass and water content partitioning were compared at the aboveground, belowground and whole-plant levels for artificial Caragana korshinskii populations between 6- and 25-year-old sites in desert steppe, northern China. The biomass was mainly allocated to third-srade branches at the aboveground level, and to firstand second-grade roots at the belowground level, and to aboveground parts at the whole-plant vegetative level. Those plant parts mentioned above became the major component of biomass pool of these shrub populations. Biomass pattern changed significantly at aboveground and/or whole-plant levels （P 〈0.05）, but not at belowground level （P 〉0.05） at 25-year-old site in comparison to 6-year-old site. Also, the water relations between dif- ferent plant parts changed considerably at all three levels from 6- to 25-year-old sites. These results imply that biomass pattern and relative water content of plant parts are correlated with the process of plantation development. The ratio of belowground to aboveground, though below 1, increased from 6- to 25-year-old site. These results suggest that these shrub populations can adjust biomass partition and relative water content of different compartments to alter their ecological adaptive strategies during stand development in desertified regions.
基金sponsored by the National Natural Science Foundation of China (2012BAK1902)
文摘We study the feature of media changes beneath the Zipingpu reservoir and discuss the process of permeation with the water level rise and fall of the reservoir from January 2005 to January 2008 from ambient noise cross correlation by using continuous seismic data recorded by the stations of Zipingpu seismic network and YZP station. A moving-window cross-spectrum technique has been used to calculate the relative seismic velocity changes between station pairs. Results revealed an obvious relationship between relative seismic velocity, and the water level changes with a time delay that may be caused by permeation during three main impoundments and two large scale disemboguements. Impoundment generates a fast and large impact on the superficial layer, and the changes of seismic velocity is the result of increased pressure and permeation during the impoundment. At the first impoundment, the main effect factor is pressure. During the next two process of impoundment, permeation becomes the main effect factor, affecting the fault at a depth of about 8kin.
文摘The marshes of southern Iraq are of great value due to their roles in the economy,environment,heritage,tourism,and agriculture.However,the region has witnessed remarkable transformations in land cover,influenced by human interventions and natural environmental factors.In this research,the Central Marshlands were selected for study and monitoring.These Marshes form the Mesopotamian Marshes,a vital part of the Tigris-Euphrates river system.This area 2 formerly covered an area of approximately 3,000 km and was once home to the lives of Marsh Arabs and their animals.The primary objective of this study was to compile a set of satellite images covering the same marshland region over several decades.The data used includes images captured by various Landsat missions:MSS(1975),TM(1983&1993),ETM+(2003),and the Operational Land Imager(OLI)from Landsat 8(2015).Satellite images were combined and pre-processed through steps such as layer stacking to create composite images from multiple bands.Several image classification methods were applied,and the classification results showed a significant and unprecedented increase in the percentage of water in the marsh,reaching 16%in 2003.This was combined with vegetation identification techniques,including the identification of vegetation boundaries to detect areas of dense vegetation.In addition,the relative depth of the water was measured to estimate marsh water levels,with the best result obtained in 2003.The normalized mean vegetation index(NDVI)calculated in this study had its best value in 1984 due to the spread of reeds and papyrus during this period.Papyrus is the raw material in the sugar industry,providing a significant economic boost.
基金funded by the Key R&D Project of Shandong Province(Grant No.2022TZXD0010)Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIP-2015-RIP-04)National Modern Agricultural Industrial Technology System Construction Project(Grant No.NYCYTX-29-ZP).
文摘Achieving global fruit demand can be realized through the application of agricultural technologies.However,it is crucial to first overcome the enormous agricultural challenges posed by the implementation of efficient irrigation technologies.To address the issues related to inadequate water supply and inefficient traditional fruit tree irrigation methods,we propose a cost-effective and efficient approach-the“439”field precision irrigation scheme.This scheme predicts four relative soil water content minimum thresholds(RSWCTs)and maximum(RSWCTe)thresholds[relative to the percentage of field capacity(FC)]for starting and ending irrigation.By exploring the relationship between RSWCTs,RSWCTeand fruit quality,we assessed the scheme's effectiveness.A practical case study was conducted on grape(Vitis vinifera L.,‘87-1')cultivated in a facility from 2019 to 2022 to evaluate the scheme's impact on irrigation management.The results indicate that maintaining70%-80%FC from germination stage(GS)to end bloom stage(EBS),70%-80%FC from EBS to veraison stage(VS),55%-70%FC from VS to maturation stage(MS),and 55%-65%FC from MS to deciduous stage(DS)improve single grain weight(SGW).Similarly,to improve total soluble solid content,60%-80%FC is suggested from GS to EBS,70%-80%FC from EBS to VS,60%-70%FC from VS to MS,and 60%-70%FC from MS to DS.To improve peel strength and fruit quality index(FQI),70%-80%FC is recommended from GS to EBS,60%-70%FC from EBS to VS,55%-65%FC from VS to MS,and 55%-70%FC from MS to DS.This management tool helps farmers optimize irrigation efficiency and increase profits by growing high-quality fruit.In summary,the implementation of the“439”field precision irrigation system,coupled with fruit quality analysis,holds promise for enhancing water efficiency in precision agriculture.
