Perennial waterlogged soil（PWS） is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is ma...Perennial waterlogged soil（PWS） is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is mainly collected from in situ measurements through groundwater level surveys and physicochemical property analyses. However, in situ measurements of PWS are costly and time-consuming, only rough estimates of PWS areas are available in some regions. In this paper, we developed a method to monitor the perennial waterlogged cropland using time-series moderate resolution imaging spectroradiometer（MODIS） data. The Jianghan Plain, a floodplain located in the middle reaches of the Yangtze River, was selected as the study area. Temporal variations of the enhanced vegetation index（EVI）, night land surface temperature（LST）, diurnal LST differences（ΔLST）, albedo, and the apparent thermal inertia（ATI） were used to analyze the ecological and thermodynamic characteristics of the waterlogged croplands. To obtain pure remote sensing signatures of the waterlogged cropland from mixed pixels, the croplands were classified into different types according to soil and land cover types in this paper, and a linear mixing model was developed by fitting the signatures using the multiple linear regression approach. Afterwards, another linear spectral mixing model was used to get the proportions of waterlogged croplands in each 1 km×1 km pixel. The result showed an acceptable accuracy with a root-mean-square error of 0.093. As a tentative method, the procedure described in this paper works efficiently as a method to monitor the spatial patterns of perennial sub-surface waterlogged croplands at a wide scale.展开更多
Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Neverthe...Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Nevertheless,the genome-wide role of ERF-VII in kiwifruit waterlogging stress tolerance remains unclear.Here,we report the function and regulatory network of an ERF-VII transcription factor located to the nucleus,Av ERF73,in kiwifruit waterlogging tolerance.Overexpression of Av ERF73 in Arabidopsis thaliana and A.chinensis cv.Hongyang enhanced waterlogging tolerance in transgenic plants.Furthermore,we performed transcriptome analysis(RNA-seq)and DNA affinity purification sequencing(DAP-seq)to explore the regulatory mechanism of Av ERF73.RNA-seq coupled with DAP-seq showed that Av ERF73 might directly activate Ac NAC022 involved in the“cellular response to hypoxia”process and Ac HMGS1 involved in the mevalonate pathway to respond to waterlogging,which were also confirmed by a dual-luciferase reporter assay.Based on our results,we propose a putative working model for controlling waterlogging tolerance by Av ERF73 in kiwifruit.展开更多
Waterlogging stress significantly impairs plant growth and reduces crop yields.Spermidine(Spd),functioning as a second messenger,demonstrates positive effects on plant growth under waterlogging stress conditions.Howev...Waterlogging stress significantly impairs plant growth and reduces crop yields.Spermidine(Spd),functioning as a second messenger,demonstrates positive effects on plant growth under waterlogging stress conditions.However,the molecular mechanisms by which exogenous Spd application alleviates waterlogging stress remain unclear.This study employed physiological analysis and multi-omics approaches to investigate the effect of Spd application on waterlogging stress.The application of Spd enhanced the expression of genes related to light-harvesting complex(LHC),photosynthesis,and starch-related pathways,while inhibiting chlorophyll degradation and maintaining higher photosynthetic rates,thereby increasing biomass accumulation under waterlogging stress.The activation of genes associated with trehalose and Spd biosynthesis resulted in elevated accumulation of trehalose and endogenous Spd.The inhibition of 1-aminocyclopropane-1-carboxylic acid(ACC)oxidase(ACO)expression contributed to reduced ethylene emission,enhancing maize resistance to waterlogging.Following Spd application,auxin-related genes were up-regulated and indole acetic acid(IAA)content increased,promoting cell elongation in maize and maintaining normal growth under waterlogging stress.Additionally,the upregulation of lipid-related genes led to increased lipid content,protecting cell membranes under waterlogging conditions.These molecular and physiological modifications collectively enhanced resistance to waterlogging stress.These findings advance our understanding of Spd's regulatory roles in mitigating waterlogging damage and provide valuable insights for breeding waterlogging-tolerant maize varieties.展开更多
Maize(Zea mays)is highly susceptible to waterlogging stress,which reduces both the yield and quality of this important crop.However,the molecular mechanism governing waterlogging tolerance is poorly understood.In this...Maize(Zea mays)is highly susceptible to waterlogging stress,which reduces both the yield and quality of this important crop.However,the molecular mechanism governing waterlogging tolerance is poorly understood.In this study,we identify a waterlogging-and ethylene-inducible gene ZmEREB179 that encodes an ethylene response factor(ERF)localized in the nucleus.Overexpression of ZmEREB179 in maize increases the sensitivity to waterlogging stress.Conversely,the zmereb179 knockout mutants are more tolerant to waterlogging,suggesting that ZmEREB179 functions as a negative regulator of waterlogging tolerance.A transcriptome analysis of the ZmEREB179-overexpressing plants reveals that the ERF-type transcription factor modulates the expression of various stress-related genes,including ZmEREB180.We find that ZmEREB179 directly targets the ZmEREB180 promoter and represses its expression.Notably,the analysis of a panel of 220 maize inbred lines reveals that genetic variations in the ZmEREB179 promoter(Hap2)are highly associated with waterlogging resistance.The functional association of Hap2 with waterlogging resistance is tightly co-segregated in two F2 segregating populations,highlighting its potential applications in breeding programs.Our findings shed light on the involvement of the transcriptional cascade of ERF genes in regulating plant-waterlogging tolerance.展开更多
The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constru...The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constructed and used in the transformation of Petunia hybrida Vilm by the Agrobacterium mediated procedure. The results of PCR amplification and Southern hybridization indicated that the vhb gene had been integrated into the petunia genome and the vhb gene expression had been detected by RT-PCR amplification. In hydroponic culture the transgenic petunias grew much better than non-transgenic controls. For further analysis of hypoxia tolerance of transgenic petunia, the petunia plants with vhb gene were submerged into liquid MS medium. The transgenic plants survived in hypoxic condition and grew out of the liquid surface in a few weeks, while non-transgenic plants were still submerged and suffocated in culture solution without ability to grow out of liquid medium in submersed culture for four to five weeks. The vhb gene transformed petunia plants had been planted and tested in a simulated flooding condition, and showed obvious tolerance to water-logging. It seen is that hemoglobin gene from Vitreoscilla might have the potential use in molecular breeding for the improvement of plant resistance to hypoxia and flooding.展开更多
[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen （N） uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was con...[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen （N） uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was conducted to investigate the effects of wateriogging through comparing WL1 （waterlogging at peak squaring stage） and WL2 （waterlogging at flowering and boll-forming stage） treatments with their controls respectively. [Result] The results showed that the effect of WL1 on N uptake of cotton root was stronger than WL2. At 20 days （d） after WL1 treatment, the root biomass （RB）, N uptake （NU）, and N uptake rate （NUR） significantly decreased by 38.1%, 48.6%, and 53.0% respectively. At 20 d after WL2 treatment, the RB, NU, and NUR significantly decreased by 27.3%, 46.0%, and 44.8% respectively. More N was distributed to root and leaf after WL1 treatment, and to square, flower, and boll after WL2 treatment. N physiological use efficiency increased by 11.4% and 44.4% after WL1 and WL2 treatments respectively. Further analysis showed that the effects of WL1 on yield and its components of cotton were stronger than WL2. The boll number, boll weight, and lint yield per plant significantly reduced by 40.5%, 12.4%, and 49.5% after WL1 treatment, and significantly decreased by 23.1%, 6.9%, and 29.9% after WL2 treatment, respectively. [Conclusion] The negative effects of water- logging at peak squaring stage on N nutrition and yield of cotton were stronger than waterlogging at flowering and boll-forming stage, indicating that more attention should be paid to waterlogging at peak squaring stage and sound N management can improve cotton regrowth and reduce yield loss after waterlogging.展开更多
[Objective] The aim was to master waterlogging tolerance of cut rose vari-eties, and provided technical reference for promoting cut rose largely. [Method] Based on natural rainfal information from July to October in S...[Objective] The aim was to master waterlogging tolerance of cut rose vari-eties, and provided technical reference for promoting cut rose largely. [Method] Based on natural rainfal information from July to October in Sanya, comprehensive performance of 22 varieties were observed in two consecutive years to analyze wa-terlogging tolerance ability of cut rose at waterlogging disaster. [Result] The mortality rates of Diana, Black Magic, Eric Red and Vendela were over 15%, and Diana ’s was 25.7%. Carola, Rouge Meil and, Perfume white, Lovers ’ Meeting, Choice, Tineke, Vendela, Marina, Samantha, Golden Emblem, Asagumo, Pink Fan and Dou-ble Delight grew better and recovered quickly after the disaster, with waterlogging tolerance. [Conclusion] The waterlogging tolerance of Carola, Rouge Meil and, My Choice, Tineke, Vendela, Marina, Samantha, Golden Emblem, Asagumo, Pink Fan and Double Delight was the best, which is also true for their comprehensive perfor-mances. But the waterlogging tolerance of other major cultivars such as Black Magic, Movie Star, Tineke and Vendela was poorer.展开更多
The effects of waterlogging stress on the growth, chlorophyll and MDA content of cucumber seedlings were studied by using cucumber varieties （Cucumis sativus L. cv. Jinyan No.7） as materials. The results show that p...The effects of waterlogging stress on the growth, chlorophyll and MDA content of cucumber seedlings were studied by using cucumber varieties （Cucumis sativus L. cv. Jinyan No.7） as materials. The results show that plant height, leaf number, shoot fresh weight, total root length, total projected area and total surface area of cucumber seedlings showed insignificant differences with those of the control; root fresh weight, root average diameter, total root volume were significantly higher, but the number of root tips and furcation number increased first and then reduced; the chlorophyll content of cucumber seedlings was significantly lower than that of control; MDA content was significantly higher than that of control under waterlogging stress. It was showed that the cucumber was tolerant to waterlogging stress, but the ability of waterlogging stress was limited, and the physiological was significantly hurt and photosynthesis of cucumber seedlings was significantly affected by waterlogging stress.展开更多
Scenario modelling and the risk assessment of natural disasters is one of the hotspots in disaster research. However, up until now, urban natural disaster risk assessments lack common procedures and programmes. This p...Scenario modelling and the risk assessment of natural disasters is one of the hotspots in disaster research. However, up until now, urban natural disaster risk assessments lack common procedures and programmes. This paper selects rainstorm waterlogging as a disaster to research, which is one of the most frequently occurring hazards for most cities in China. As an example, we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing＇an District of Shanghai. Based on the basic concept of disaster risk, this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods. Through this analysis of vulnerability and exposure, we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments. A grid-based Geographical Information System （GIS） approach, including an urban terrain model, an urban rainfall model and an urban drainage model, was applied to simulate inundation area and depth. Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys, which were further applied to analyse vulnerability, exposure and loss assessment. Finally, the exceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities. A framework was also developed for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss. This is a new exploration for small-scale urban natural disaster scenario simulation and risk assessment.展开更多
To better understand the physiological and biochemical mechanisms of waterlogging tolerance, waterlogging effects on lipid peroxidation and the activity of antioxidative enzymes were investigated in leaves and roots o...To better understand the physiological and biochemical mechanisms of waterlogging tolerance, waterlogging effects on lipid peroxidation and the activity of antioxidative enzymes were investigated in leaves and roots of two maize genotypes, HZ32 （waterlogging-tolerant） and K12 （waterlogging-sensitive）. Potted maize plants were waterlogged at the second leaf stage under glasshouse conditions. Leaves and roots were harvested 1 d before and 2, 4, 6, 8 and 10 d after the start of waterlogging treatment. Through comparing the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, glutathione reductase （GR）, catalase （CAT） and guaiacol peroxidase （POD） between waterlogging-tolerant and waterloggingsensitive genotype, we deduced that CAT was the most important H2O2 scavenging enzyme in leaves, while APX seemed to play a key role in roots. POD, APX, GR and CAT activities in conjunction with SOD seem to play an essential protective role in the O2^- and H2O2 scavenging process. Lipid peroxidation was enhanced significantly only in K12 （P 〈 0.001） and there was no difference （P 〉 0.05） in HZ32 up to 6 d after waterlogging stress. These results indicated that oxidative stress may play an important role in waterlogging-stressed maize plants and that the greater protection of HZ32 leaves and roots from waterlogging-induced oxidative damage results, at least in part, through the maintenance of increased antioxidant enzyme activity.展开更多
Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR...Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.展开更多
RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of wate...RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of waterlogging tolerance beyond natural variation. A total of 2 977 genes with similar expression patterns and 17 genes with opposite expression patterns were identiifed in the transcription proifles of ZS9 and GH01. An additional 1 438 genes in ZS9 and 1 861 genes in GH01 showed strain speciifc regulation. Analysis of the overlapped genes between ZS9 and GH01 revealed that waterlogging tolerance is determined by ability to regulate genes with similar expression patterns. Moreover, differences in both gene expression proifles and abscisic acid (ABA) contents between the two varieties suggest that ABA may play some role in waterlogging tolerance. This study identiifes a subset of candidate genes for further functional analysis.展开更多
A field experiment was carried out to study genotypic difference in the effect of waterlogging on photosynthesis, chlorophyll content and antioxidative enzyme activities in barley. Waterlogging caused a rapid decline ...A field experiment was carried out to study genotypic difference in the effect of waterlogging on photosynthesis, chlorophyll content and antioxidative enzyme activities in barley. Waterlogging caused a rapid decline in net photosynthetic rate (Pn) and stomatal conductance (gs), and little change in chlorophyll content during early days of the treatment. A dramatic increase in malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) in waterlogged plants in the early days of the experiment was found, indicating the occurrence of oxidative stress in barley plants exposed to waterlogging. There was a highly significant difference in the changed extent of all these parameters among genotypes. Franklin and Yongjiahong Liuleng Damai, which were relatively sensitive to waterlogging in terms of growth, photosynthesis and chlorophyll content, accumulated much more MDA than the other two relatively tolerant genotypes (93-3143 and QS). After removal of waterlogging, the genotypic difference became much greater in recovering of these examined parameters. Yongjiahong Liuleng Damai showed higher recovery, while Franklin only recovered to 50% of the control at the 14 day after waterlogging removal. It may be concluded that it is the difference in anti-oxidative stress caused by waterlogging that account for the major difference in photosynthesis among barley genotypes.展开更多
Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on wa-te...Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on wa-terlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1km×1km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin.展开更多
Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reason...Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability（GCA） and special combining ability（SCA） of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.展开更多
Due to rapid urbanization, waterlogging induced by torrential rainfall has become a global concern and a potential risk affecting urban habitant's safety. Widespread waterlogging disasters haveoccurred almost annu...Due to rapid urbanization, waterlogging induced by torrential rainfall has become a global concern and a potential risk affecting urban habitant's safety. Widespread waterlogging disasters haveoccurred almost annuallyinthe urban area of Beijing, the capital of China. Based on a selforganizing map(SOM) artificial neural network(ANN), a graded waterlogging risk assessment was conducted on 56 low-lying points in Beijing, China. Social risk factors, such as Gross domestic product(GDP), population density, and traffic congestion, were utilized as input datasets in this study. The results indicate that SOM-ANNis suitable for automatically and quantitatively assessing risks associated with waterlogging. The greatest advantage of SOM-ANN in the assessment of waterlogging risk is that a priori knowledge about classification categories and assessment indicator weights is not needed. As a result, SOM-ANN can effectively overcome interference from subjective factors,producing classification results that are more objective and accurate. In this paper, the risk level of waterlogging in Beijing was divided into five grades. The points that were assigned risk grades of IV or Vwere located mainly in the districts of Chaoyang, Haidian, Xicheng, and Dongcheng.展开更多
Over the last few decades,waterlogging stress has increasingly threatened global cotton production.Waterlogging results in reduced soil oxygen,impairing the growth and development of this valuable crop and often resul...Over the last few decades,waterlogging stress has increasingly threatened global cotton production.Waterlogging results in reduced soil oxygen,impairing the growth and development of this valuable crop and often resulting in severe yield loss or crop failure.However,as cotton has an indeterminate growth habit,it is able to adapt to waterlogging stress by activating three mechanisms:the escape,quiescence,and self-regulating compensation mechanisms.The escape mechanism includes accelerated growth,formation of adventitious roots,and production of aerenchyma.The quiescence mechanism involves reduced biomass accumulation and energy dissipation via physiological,biochemical,and molecular events.The self-regulation compensation mechanism allows plants to exploit their indeterminate growth habit and compensatory growth ability by accelerating growth and development following relief from waterlogging stress.We review how the growth and development of cotton is impaired by waterlogging,focusing on the three strategies associated with tolerance and adaptation to the stress.We discuss agronomic measures and prospects for mitigating the adverse effects of waterlogging stress.展开更多
Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrig...Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.展开更多
Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM1...Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM102)and‘Yangmai158’(YM158)were planted to study the dynamic changes of photosynthetic characteristics in flag leaf and the influence of waterlogging at anthesis on the yield and components and dry matter accumulation and remobilization of winter wheat in above ground.The results showed that the SPAD values slightly increased at 1 day after anthesis(d),and then kept decreasing with the increase of waterlogging time.The decrease in SPAD value was more remarkably in YM158 than that in JM102.As for the chlorophyll fluorescence parameters,the photochemical efficiency(Fv/Fm),potential activity(Fv/Fo)of photosystem II,and electronic transmission(Fm/Fo)on photosystem II increased first and then decreased with the increase of waterlogging days after anthesis.The quantum ratio of heat dissipation(Fo/Fm)had a tendency opposite to that of Fv/Fm,and the change range of JM102 was lower than that of YM158.For the grain yield and components,waterlogging at anthesis decreased the dry weight of single stem,grain yield,1 000-kernel weight,spikelet per panicle,and harvest index,and the reduction of JM102 was smaller than that of YM158.As for the accumulation and remobilization of dry matter,the accumulation of dry matter after anthesis decreased significantly under waterlogging condition(WL),and the reduction of JM102 was smaller than that of YM158.In conclusion,waterlogging at anthesis significantly affected the photosynthetic characteristics,yield and components in both varieties,but different varieties exhibited different tolerances to waterlogging stress and YM158 was more sensitive to water stress than JM102.展开更多
In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), wh...In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), which was computed by using AMSR-E data at 37GHz, vertically and horizontally polarized brightness temperature values and the water surface fraction (WSF) got by using the PRI at 37GHz. Moderate Resolution Imaging Spectrora-diometer (MODIS) data were used to validate the WSF values. The analysis of flood and waterlogging using the WSF map on July 6, 2003 indicates that the use of WSF for flood and waterlogging disaster assessment is feasible. Utilizing the correlation of WSF derived from AMSR-E and water area derived from MODIS, the water area of the Huaihe River Basin were computed by only using AMSR-E data in the summer of 2003, which overcame the influence of cloud on water estimation using MODIS data during flood.展开更多
基金supported by the National Basic Research Program of China (2012CB417001)the National Natural Science Foundation of China (41271125)
文摘Perennial waterlogged soil（PWS） is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is mainly collected from in situ measurements through groundwater level surveys and physicochemical property analyses. However, in situ measurements of PWS are costly and time-consuming, only rough estimates of PWS areas are available in some regions. In this paper, we developed a method to monitor the perennial waterlogged cropland using time-series moderate resolution imaging spectroradiometer（MODIS） data. The Jianghan Plain, a floodplain located in the middle reaches of the Yangtze River, was selected as the study area. Temporal variations of the enhanced vegetation index（EVI）, night land surface temperature（LST）, diurnal LST differences（ΔLST）, albedo, and the apparent thermal inertia（ATI） were used to analyze the ecological and thermodynamic characteristics of the waterlogged croplands. To obtain pure remote sensing signatures of the waterlogged cropland from mixed pixels, the croplands were classified into different types according to soil and land cover types in this paper, and a linear mixing model was developed by fitting the signatures using the multiple linear regression approach. Afterwards, another linear spectral mixing model was used to get the proportions of waterlogged croplands in each 1 km×1 km pixel. The result showed an acceptable accuracy with a root-mean-square error of 0.093. As a tentative method, the procedure described in this paper works efficiently as a method to monitor the spatial patterns of perennial sub-surface waterlogged croplands at a wide scale.
基金funded by the National Key Research and Development Program(Grant No.2022YFD1600700)Major Science and Technology Projects of Henan Province(Grant No.221100110400)+3 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS-26)Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(Grant No.CAAS-ASTIP-2023-ZFRI-03)Yunnan Science and Technology Program(Grant No.202205AF150043)Sichuan Science and Technology Program(Grant No.2021YFN0060)。
文摘Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Nevertheless,the genome-wide role of ERF-VII in kiwifruit waterlogging stress tolerance remains unclear.Here,we report the function and regulatory network of an ERF-VII transcription factor located to the nucleus,Av ERF73,in kiwifruit waterlogging tolerance.Overexpression of Av ERF73 in Arabidopsis thaliana and A.chinensis cv.Hongyang enhanced waterlogging tolerance in transgenic plants.Furthermore,we performed transcriptome analysis(RNA-seq)and DNA affinity purification sequencing(DAP-seq)to explore the regulatory mechanism of Av ERF73.RNA-seq coupled with DAP-seq showed that Av ERF73 might directly activate Ac NAC022 involved in the“cellular response to hypoxia”process and Ac HMGS1 involved in the mevalonate pathway to respond to waterlogging,which were also confirmed by a dual-luciferase reporter assay.Based on our results,we propose a putative working model for controlling waterlogging tolerance by Av ERF73 in kiwifruit.
基金supported by the China Agriculture Research System(CARS-02-20)the Henan Province Agro-ecosystem Field Observation and Research Station,China(30602535)。
文摘Waterlogging stress significantly impairs plant growth and reduces crop yields.Spermidine(Spd),functioning as a second messenger,demonstrates positive effects on plant growth under waterlogging stress conditions.However,the molecular mechanisms by which exogenous Spd application alleviates waterlogging stress remain unclear.This study employed physiological analysis and multi-omics approaches to investigate the effect of Spd application on waterlogging stress.The application of Spd enhanced the expression of genes related to light-harvesting complex(LHC),photosynthesis,and starch-related pathways,while inhibiting chlorophyll degradation and maintaining higher photosynthetic rates,thereby increasing biomass accumulation under waterlogging stress.The activation of genes associated with trehalose and Spd biosynthesis resulted in elevated accumulation of trehalose and endogenous Spd.The inhibition of 1-aminocyclopropane-1-carboxylic acid(ACC)oxidase(ACO)expression contributed to reduced ethylene emission,enhancing maize resistance to waterlogging.Following Spd application,auxin-related genes were up-regulated and indole acetic acid(IAA)content increased,promoting cell elongation in maize and maintaining normal growth under waterlogging stress.Additionally,the upregulation of lipid-related genes led to increased lipid content,protecting cell membranes under waterlogging conditions.These molecular and physiological modifications collectively enhanced resistance to waterlogging stress.These findings advance our understanding of Spd's regulatory roles in mitigating waterlogging damage and provide valuable insights for breeding waterlogging-tolerant maize varieties.
基金supported by the science and technology major program of Hubei Province(2022ABA001)the National Key Research and Development Program of Shandong Province(2022CXPT014)the Knowledge Innovation Program of Wuhan-Shugung Project(2023020201020413).
文摘Maize(Zea mays)is highly susceptible to waterlogging stress,which reduces both the yield and quality of this important crop.However,the molecular mechanism governing waterlogging tolerance is poorly understood.In this study,we identify a waterlogging-and ethylene-inducible gene ZmEREB179 that encodes an ethylene response factor(ERF)localized in the nucleus.Overexpression of ZmEREB179 in maize increases the sensitivity to waterlogging stress.Conversely,the zmereb179 knockout mutants are more tolerant to waterlogging,suggesting that ZmEREB179 functions as a negative regulator of waterlogging tolerance.A transcriptome analysis of the ZmEREB179-overexpressing plants reveals that the ERF-type transcription factor modulates the expression of various stress-related genes,including ZmEREB180.We find that ZmEREB179 directly targets the ZmEREB180 promoter and represses its expression.Notably,the analysis of a panel of 220 maize inbred lines reveals that genetic variations in the ZmEREB179 promoter(Hap2)are highly associated with waterlogging resistance.The functional association of Hap2 with waterlogging resistance is tightly co-segregated in two F2 segregating populations,highlighting its potential applications in breeding programs.Our findings shed light on the involvement of the transcriptional cascade of ERF genes in regulating plant-waterlogging tolerance.
文摘The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constructed and used in the transformation of Petunia hybrida Vilm by the Agrobacterium mediated procedure. The results of PCR amplification and Southern hybridization indicated that the vhb gene had been integrated into the petunia genome and the vhb gene expression had been detected by RT-PCR amplification. In hydroponic culture the transgenic petunias grew much better than non-transgenic controls. For further analysis of hypoxia tolerance of transgenic petunia, the petunia plants with vhb gene were submerged into liquid MS medium. The transgenic plants survived in hypoxic condition and grew out of the liquid surface in a few weeks, while non-transgenic plants were still submerged and suffocated in culture solution without ability to grow out of liquid medium in submersed culture for four to five weeks. The vhb gene transformed petunia plants had been planted and tested in a simulated flooding condition, and showed obvious tolerance to water-logging. It seen is that hemoglobin gene from Vitreoscilla might have the potential use in molecular breeding for the improvement of plant resistance to hypoxia and flooding.
基金Supported by Jiangsu Agricultural Science and Technology Independent-innovation Fund Project(SCX(13)5071)National Natural Science Foundation of China(30900877)~~
文摘[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen （N） uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was conducted to investigate the effects of wateriogging through comparing WL1 （waterlogging at peak squaring stage） and WL2 （waterlogging at flowering and boll-forming stage） treatments with their controls respectively. [Result] The results showed that the effect of WL1 on N uptake of cotton root was stronger than WL2. At 20 days （d） after WL1 treatment, the root biomass （RB）, N uptake （NU）, and N uptake rate （NUR） significantly decreased by 38.1%, 48.6%, and 53.0% respectively. At 20 d after WL2 treatment, the RB, NU, and NUR significantly decreased by 27.3%, 46.0%, and 44.8% respectively. More N was distributed to root and leaf after WL1 treatment, and to square, flower, and boll after WL2 treatment. N physiological use efficiency increased by 11.4% and 44.4% after WL1 and WL2 treatments respectively. Further analysis showed that the effects of WL1 on yield and its components of cotton were stronger than WL2. The boll number, boll weight, and lint yield per plant significantly reduced by 40.5%, 12.4%, and 49.5% after WL1 treatment, and significantly decreased by 23.1%, 6.9%, and 29.9% after WL2 treatment, respectively. [Conclusion] The negative effects of water- logging at peak squaring stage on N nutrition and yield of cotton were stronger than waterlogging at flowering and boll-forming stage, indicating that more attention should be paid to waterlogging at peak squaring stage and sound N management can improve cotton regrowth and reduce yield loss after waterlogging.
基金Supported by National Science and Technology Project(2013GB2E200390)Hainan Major Science and Technology Project(ZDZX2013012-3)~~
文摘[Objective] The aim was to master waterlogging tolerance of cut rose vari-eties, and provided technical reference for promoting cut rose largely. [Method] Based on natural rainfal information from July to October in Sanya, comprehensive performance of 22 varieties were observed in two consecutive years to analyze wa-terlogging tolerance ability of cut rose at waterlogging disaster. [Result] The mortality rates of Diana, Black Magic, Eric Red and Vendela were over 15%, and Diana ’s was 25.7%. Carola, Rouge Meil and, Perfume white, Lovers ’ Meeting, Choice, Tineke, Vendela, Marina, Samantha, Golden Emblem, Asagumo, Pink Fan and Dou-ble Delight grew better and recovered quickly after the disaster, with waterlogging tolerance. [Conclusion] The waterlogging tolerance of Carola, Rouge Meil and, My Choice, Tineke, Vendela, Marina, Samantha, Golden Emblem, Asagumo, Pink Fan and Double Delight was the best, which is also true for their comprehensive perfor-mances. But the waterlogging tolerance of other major cultivars such as Black Magic, Movie Star, Tineke and Vendela was poorer.
文摘The effects of waterlogging stress on the growth, chlorophyll and MDA content of cucumber seedlings were studied by using cucumber varieties （Cucumis sativus L. cv. Jinyan No.7） as materials. The results show that plant height, leaf number, shoot fresh weight, total root length, total projected area and total surface area of cucumber seedlings showed insignificant differences with those of the control; root fresh weight, root average diameter, total root volume were significantly higher, but the number of root tips and furcation number increased first and then reduced; the chlorophyll content of cucumber seedlings was significantly lower than that of control; MDA content was significantly higher than that of control under waterlogging stress. It was showed that the cucumber was tolerant to waterlogging stress, but the ability of waterlogging stress was limited, and the physiological was significantly hurt and photosynthesis of cucumber seedlings was significantly affected by waterlogging stress.
基金National Nature Science Foundation of China, No.41071324 No.40730526+2 种基金 Key Subject Developing Project by Shanghai Municipal Education Commission, No.J50402 Science and Technology Commission of Shanghai Municipality, No.08240514000 Leading Academic Discipline Project of Shanghai Normal University, No.DZL809
文摘Scenario modelling and the risk assessment of natural disasters is one of the hotspots in disaster research. However, up until now, urban natural disaster risk assessments lack common procedures and programmes. This paper selects rainstorm waterlogging as a disaster to research, which is one of the most frequently occurring hazards for most cities in China. As an example, we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing＇an District of Shanghai. Based on the basic concept of disaster risk, this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods. Through this analysis of vulnerability and exposure, we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments. A grid-based Geographical Information System （GIS） approach, including an urban terrain model, an urban rainfall model and an urban drainage model, was applied to simulate inundation area and depth. Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys, which were further applied to analyse vulnerability, exposure and loss assessment. Finally, the exceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities. A framework was also developed for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss. This is a new exploration for small-scale urban natural disaster scenario simulation and risk assessment.
基金supported by the Natural Science Foundation of Hubei Province, China (2008CDB079)the National High Technology Research and Development Program of China (863 Program, 2006AA100103)
文摘To better understand the physiological and biochemical mechanisms of waterlogging tolerance, waterlogging effects on lipid peroxidation and the activity of antioxidative enzymes were investigated in leaves and roots of two maize genotypes, HZ32 （waterlogging-tolerant） and K12 （waterlogging-sensitive）. Potted maize plants were waterlogged at the second leaf stage under glasshouse conditions. Leaves and roots were harvested 1 d before and 2, 4, 6, 8 and 10 d after the start of waterlogging treatment. Through comparing the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, glutathione reductase （GR）, catalase （CAT） and guaiacol peroxidase （POD） between waterlogging-tolerant and waterloggingsensitive genotype, we deduced that CAT was the most important H2O2 scavenging enzyme in leaves, while APX seemed to play a key role in roots. POD, APX, GR and CAT activities in conjunction with SOD seem to play an essential protective role in the O2^- and H2O2 scavenging process. Lipid peroxidation was enhanced significantly only in K12 （P 〈 0.001） and there was no difference （P 〉 0.05） in HZ32 up to 6 d after waterlogging stress. These results indicated that oxidative stress may play an important role in waterlogging-stressed maize plants and that the greater protection of HZ32 leaves and roots from waterlogging-induced oxidative damage results, at least in part, through the maintenance of increased antioxidant enzyme activity.
基金supported by the National Basic Research Program of China (2011CB100100)the National High-Tech R&D Program of China (2011AA100103)the National Natural Science Foundation of China (31230053 and 31171556)
文摘Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.
文摘RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of waterlogging tolerance beyond natural variation. A total of 2 977 genes with similar expression patterns and 17 genes with opposite expression patterns were identiifed in the transcription proifles of ZS9 and GH01. An additional 1 438 genes in ZS9 and 1 861 genes in GH01 showed strain speciifc regulation. Analysis of the overlapped genes between ZS9 and GH01 revealed that waterlogging tolerance is determined by ability to regulate genes with similar expression patterns. Moreover, differences in both gene expression proifles and abscisic acid (ABA) contents between the two varieties suggest that ABA may play some role in waterlogging tolerance. This study identiifes a subset of candidate genes for further functional analysis.
基金The work was supported in part by the Ministry of Science and Technology of China(China-Australian Special Link Research Program),Australian Bureau of Cereal Research and Development(UT-8)and the Na-tional 863 Program,China(2001AA241241).
文摘A field experiment was carried out to study genotypic difference in the effect of waterlogging on photosynthesis, chlorophyll content and antioxidative enzyme activities in barley. Waterlogging caused a rapid decline in net photosynthetic rate (Pn) and stomatal conductance (gs), and little change in chlorophyll content during early days of the treatment. A dramatic increase in malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) in waterlogged plants in the early days of the experiment was found, indicating the occurrence of oxidative stress in barley plants exposed to waterlogging. There was a highly significant difference in the changed extent of all these parameters among genotypes. Franklin and Yongjiahong Liuleng Damai, which were relatively sensitive to waterlogging in terms of growth, photosynthesis and chlorophyll content, accumulated much more MDA than the other two relatively tolerant genotypes (93-3143 and QS). After removal of waterlogging, the genotypic difference became much greater in recovering of these examined parameters. Yongjiahong Liuleng Damai showed higher recovery, while Franklin only recovered to 50% of the control at the 14 day after waterlogging removal. It may be concluded that it is the difference in anti-oxidative stress caused by waterlogging that account for the major difference in photosynthesis among barley genotypes.
基金Under the auspices of Ministry of Water Resources, P. R. China (No. [2001]29)
文摘Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on wa-terlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1km×1km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin.
基金supported by the National High-Tech Research and Development Program of China (863 Program,2006AA10Z1C2)the Key Technologies R&D Program of China during the 10th Five-Year Plan period (2009BADA8B01,2110BAD01B09)the Natural Science Foundation of Hubei Province,China(2009CDA089)
文摘Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability（GCA） and special combining ability（SCA） of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.
基金supported by the National Key R&D Program of China (GrantN o.2016YFC0401407)National Natural Science Foundation of China (Grant Nos. 51479003 and 51279006)
文摘Due to rapid urbanization, waterlogging induced by torrential rainfall has become a global concern and a potential risk affecting urban habitant's safety. Widespread waterlogging disasters haveoccurred almost annuallyinthe urban area of Beijing, the capital of China. Based on a selforganizing map(SOM) artificial neural network(ANN), a graded waterlogging risk assessment was conducted on 56 low-lying points in Beijing, China. Social risk factors, such as Gross domestic product(GDP), population density, and traffic congestion, were utilized as input datasets in this study. The results indicate that SOM-ANNis suitable for automatically and quantitatively assessing risks associated with waterlogging. The greatest advantage of SOM-ANN in the assessment of waterlogging risk is that a priori knowledge about classification categories and assessment indicator weights is not needed. As a result, SOM-ANN can effectively overcome interference from subjective factors,producing classification results that are more objective and accurate. In this paper, the risk level of waterlogging in Beijing was divided into five grades. The points that were assigned risk grades of IV or Vwere located mainly in the districts of Chaoyang, Haidian, Xicheng, and Dongcheng.
基金This work was supported by the National Key Research and Development Program of China(2018YFD1000907)National Natural Science Foundation of China(31771718,31801307)+1 种基金Natural Science Foundation of Shandong Province(ZR2018BC033)Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2016B05 and CXGC2018E06).
文摘Over the last few decades,waterlogging stress has increasingly threatened global cotton production.Waterlogging results in reduced soil oxygen,impairing the growth and development of this valuable crop and often resulting in severe yield loss or crop failure.However,as cotton has an indeterminate growth habit,it is able to adapt to waterlogging stress by activating three mechanisms:the escape,quiescence,and self-regulating compensation mechanisms.The escape mechanism includes accelerated growth,formation of adventitious roots,and production of aerenchyma.The quiescence mechanism involves reduced biomass accumulation and energy dissipation via physiological,biochemical,and molecular events.The self-regulation compensation mechanism allows plants to exploit their indeterminate growth habit and compensatory growth ability by accelerating growth and development following relief from waterlogging stress.We review how the growth and development of cotton is impaired by waterlogging,focusing on the three strategies associated with tolerance and adaptation to the stress.We discuss agronomic measures and prospects for mitigating the adverse effects of waterlogging stress.
基金financially supported by the National Natural Science Foundation of China (51741908)
文摘Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.
基金Supported by the National Key Research and Development Program of China(2016YFD0300107,2017YFD0300202-3)National Natural Science Foundation of China(31371580,31871578)
文摘Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM102)and‘Yangmai158’(YM158)were planted to study the dynamic changes of photosynthetic characteristics in flag leaf and the influence of waterlogging at anthesis on the yield and components and dry matter accumulation and remobilization of winter wheat in above ground.The results showed that the SPAD values slightly increased at 1 day after anthesis(d),and then kept decreasing with the increase of waterlogging time.The decrease in SPAD value was more remarkably in YM158 than that in JM102.As for the chlorophyll fluorescence parameters,the photochemical efficiency(Fv/Fm),potential activity(Fv/Fo)of photosystem II,and electronic transmission(Fm/Fo)on photosystem II increased first and then decreased with the increase of waterlogging days after anthesis.The quantum ratio of heat dissipation(Fo/Fm)had a tendency opposite to that of Fv/Fm,and the change range of JM102 was lower than that of YM158.For the grain yield and components,waterlogging at anthesis decreased the dry weight of single stem,grain yield,1 000-kernel weight,spikelet per panicle,and harvest index,and the reduction of JM102 was smaller than that of YM158.As for the accumulation and remobilization of dry matter,the accumulation of dry matter after anthesis decreased significantly under waterlogging condition(WL),and the reduction of JM102 was smaller than that of YM158.In conclusion,waterlogging at anthesis significantly affected the photosynthetic characteristics,yield and components in both varieties,but different varieties exhibited different tolerances to waterlogging stress and YM158 was more sensitive to water stress than JM102.
基金Under the auspices of the Foundation of the Ministry of Science and Technology (No 2003DKA1T007, No 2005DFA20010)
文摘In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), which was computed by using AMSR-E data at 37GHz, vertically and horizontally polarized brightness temperature values and the water surface fraction (WSF) got by using the PRI at 37GHz. Moderate Resolution Imaging Spectrora-diometer (MODIS) data were used to validate the WSF values. The analysis of flood and waterlogging using the WSF map on July 6, 2003 indicates that the use of WSF for flood and waterlogging disaster assessment is feasible. Utilizing the correlation of WSF derived from AMSR-E and water area derived from MODIS, the water area of the Huaihe River Basin were computed by only using AMSR-E data in the summer of 2003, which overcame the influence of cloud on water estimation using MODIS data during flood.
