Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the g...Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the growth and production of maize(Zea mays L)in addition to the water use efficiency in soils with different gypsum content.The experimental treatments include three irrigation treatments,i.e.Conventional Irrigation(CI),Alternate Partial Root-zone Drying(APRD)and Fixed Partial Root-zone Drying(FPRD),and three soils with different gypsum content"(60.0[G1],153.7[G2],and 314.2[G3]g kg^(-1))".The vegetative growth,root dry mass and physiological indices(leaf relative water content,carotenoid concentration,proline)have been studied during three stages of maize plant growth(jointing,tasselling,and maturing).The Results showed that compared to CI,APRD and FPRD increased water use efficiency by 38.93 and 14.94%based on dry seed yield.In addition,compared to CI,APRD increased maize seed yield by 4.62-20.71%,while FPRD decreased yield by 19.24-5.28%for the gypsiferous soils G2 and G3,respectively.APRD has a slight effect on leaf water potential,leaf relative water content,carotenoid and proline activities from jointing to maturing stages at the three gypsiferous soils.Results suggest that APRD could make maize plants use water even more productively with better adaptation to water shortages in the gypsiferous soils.展开更多
Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse e...Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be considered as a water-saving strategy for greenhouse tomato production.展开更多
Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breedin...Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.展开更多
Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was perfor...Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water (D2O) in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.展开更多
Water is the main factor for the healthy life of plant.One of the main negative effects of climate change is the increasing scarcity of water that is lethal for plant.Globally,for water deficit regions(arid and semi-a...Water is the main factor for the healthy life of plant.One of the main negative effects of climate change is the increasing scarcity of water that is lethal for plant.Globally,for water deficit regions(arid and semi-arid),drought is the main factor responsible for low production of agriculture,especially for cotton.Great efforts have been and are being made to find alternatives to water saving practices.This study aimed to examine the effects of partial rhizosphere drying(PRD,half of the root system irrigated at one event,and the other half irrigated in the next event,and so on)with and/or without various mulching treatments on physiological and biochemical traits of cotton.To explore this objective,we laid out experiments in completely randomized design with factorial arrangement in the Islamia University of Bahawalpur,Pakistan in 2016.Two factors included were four mulching treatments(M0,no mulching;M1,black plastic mulching;M2,wheat straw mulching;and M3,cotton sticks mulching)and two irrigation levels(I0,control(full irrigation);and I1,PRD).Fisher's analysis of variance among means of treatments was compared using least significant difference test at 5% probability level.Results revealed that the maximum plant height,leaf area,leaf gas exchange(photosynthetic rate and stomata conductance),chlorophyll,proline and total sugar contents,and enzyme activities were higher under M2 than under other three mulching treatments.As for irrigation levels,higher values of plant height,photosynthesis and water related parameters(leaf water potential,leaf osmotic potential,leaf turgor potential,etc.)were recorded.Contents of total sugar and proline and activities of antioxidant enzymes were significantly higher in PRD-treated plants than in control plants.It was concluded that combined application of PRD and mulching was more effective than the rest of the treatments used in the experiment.Similar study can be conducted in the field by applying irrigation water in alternate rows in semi-arid regions.展开更多
To lay a biological foundation for rootstocks and alternate irrigation (AI) popularization, the effects of partial rootzone drying (PRD) on the growth of the grapevine Malvasia grafted on different rootstocks were...To lay a biological foundation for rootstocks and alternate irrigation (AI) popularization, the effects of partial rootzone drying (PRD) on the growth of the grapevine Malvasia grafted on different rootstocks were investigated. Biological effects of 1/2 divided root irrigation on three combinations, i.e., Malvasia/420A, Malvasia/3309C, and Malvasia/110R, were studied by wood-boxed plants. All the plants were separated into three groups for different irrigation strategies. Mass growth of new root in alternate-irrigated plants was remarkably promoted by about 7.8-22.2% higher than the well- watered ones. However, new shoot growth, especially the internode was reduced by alternate irrigation. The average root-shoot ratio of all the three combinations was increased from 1.1 to 1.46. New root growth and internode length were decreased by fixed partial rootzone irrigation (FI) at different amount, M/3309C at 37.9 and 36.9%, M/110R at 18.4 and 22.5%, respectively. Total biomass of all the three combinations under FI decreased at the rate of 19.2-34.3% compared with well-watered ones. Water stress adaptation of grapevine mainly depends on rootstock. 110R is more efficient than 3309C and 420A in water stress adaptation. PRD-AI benefited root growth, thus improved the drought-resistant ability of grapevine.展开更多
Partial Rootzone Drying (PRD) is an irrigation technique which offers a means of modifying the growth and development of crops through relatively simple changes to the method of water delivery. The technique causes th...Partial Rootzone Drying (PRD) is an irrigation technique which offers a means of modifying the growth and development of crops through relatively simple changes to the method of water delivery. The technique causes the stimulation of physiological responses which are normally associated with water stress and this results in a significant reduction in water use through the production of chemical signals in drying roots. Partial drying of one half of the roots of plants grown with two root systems is rapidly translated into a reduction in transpiration and assimilation of all the crop leaves. The aim of this research is to examine and simulate the novel irrigation method (PRD), which would stimulate the endogenous stress response mechanisms of Conocarpus erectus trees in the pilot area of the Arabian Gulf University in Bahrain and wheat and maize crops in the Mashtul Pilot Area (MPA), Egypt using Saltmed model so that vigor is reduced and the efficiency of water use is enhanced. This is to be achieved by the manipulation of the hydration status of parts of a crop’s roots that could be used to control vegetative vigor without detrimental effects on canopy water relations. The PRD technique is researched for wheat as a winter crop and maize as a summer crop in Egypt. The technique causes the stimulation of physiological responses which are normally associated with water stress and this results in a significant reduction in water use through the production of chemical signals in drying roots. The results confirmed an increase in irrigation water use efficiency using PRD comparing with conventional flood irrigation. The research highly recommends applying the PRD method in the Gulf Cooperation Council (GCC) countries and in new reclaimed areas in Egypt to save water and improve crop quality.展开更多
Redox catalysts play a vital role in the interconversion of two significant greenhouse gases,CO_(2)and CH_(4),via chemical looping methane dry reforming technology.Herein,a series of transition metals-alloyed and core...Redox catalysts play a vital role in the interconversion of two significant greenhouse gases,CO_(2)and CH_(4),via chemical looping methane dry reforming technology.Herein,a series of transition metals-alloyed and core-shell structured Ni-M/SiO_(2)@CeO_(2)(M=Fe,Co,Cu,Mn,Zr)redox catalyst were fabricated and evaluated in a gas-solid fixed-bed reactor for cycling CH_(4)partial oxidation(PO_(x))and CO_(2)splitting.The catalysts are composed of spherical SiO_(2)core and CeO_(2)shell,and the highly dispersed Ni alloy nanoparticles are the interlayer between core and shell.The oxygen vacancy concentration of Ni-M/SiO_(2)@CeO_(2)followed the order of Co>Cu>Fe>Mn>Zr,and Ni alloying with transition metals significantly enhanced oxygen storage capacity(OSC).Ni-Co/SiO_(2)@CeO_(2)catalyst with abundant oxygen vacancies and a high OSC showed the lowest temperatures of CH_(4)activation(610℃)and CO_(2)decomposition(590℃),thus demonstrating excellent redox reactivity.The catalyst exhibited superior activity and structural stability in the continuous CH_(4)/CO_(2)redox cycles at 615℃,achieving 87%CH_(4)conversion and 83%CO selectivity.The proposed catalyst shows great potential for the utilization of CH_(4)and CO_(2)in a redox mode,providing a new sight for design redox catalyst in chemical looping or related fields.展开更多
Production of cocoa butter replacer (CBR) from tea seed oil through common modification methods of oils (dry fractionation, partial hydrogenation, chemical and enzymatic interesterification) was evaluated. Some physic...Production of cocoa butter replacer (CBR) from tea seed oil through common modification methods of oils (dry fractionation, partial hydrogenation, chemical and enzymatic interesterification) was evaluated. Some physico-chemical properties (iodine, saponification, acid and peroxide values) and fatty acid composition (FAC) of modified samples were analyzed and compared with a reference cocoa butter (CB). Solid and liquid fractions for large amounts of unsaturated fatty acids (approx. 80%) and thereby lower iodine values (81 - 85 gI2/100g) than that of CB (37% and 34 gI2/100 g, respectively), are not suitable as CBR. Among all ratios of chemically and enzaymatically interesterified oil blends (20%, 25% and 30% of hydrogenated tea seed oil with 80%, 75% and 70% of tea seed oil/liquid fraction/solid fraction), the samples with ratio of 30:70 from both chemical and enzymatic interesterification had FAC and iodine value closer to that of CB. A comparision between chemically and enzymatically interesterified samples (CISs and EISs, respectively), in terms of solid fat content (SFC) indicated that although the SFC values in EIS were much lower than that of CB, but the thermal behavior of this sample is comprable to CB at 20℃- 30℃ (sharp melting point of CB).展开更多
Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-...Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot experiments.There were four combinations of irrigation levels and growing stages of tomato for AI,i.e.AI_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,i.e.low urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of urea.Irrigation quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,respectively.Compared to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,respectively.AI_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)significantly.Compared to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,respectively.Compared to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,respectively.Therefore,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.展开更多
Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use ...Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.展开更多
A pot experiment was conducted to investigate the effects of different water and nitrogen supply amounts on the comprehensive assessment of tomato fruit quality and root growth parameters under alternate partial root-...A pot experiment was conducted to investigate the effects of different water and nitrogen supply amounts on the comprehensive assessment of tomato fruit quality and root growth parameters under alternate partial root-zone irrigation.Three upper irrigation limitations(i.e.70%(W1),80%(W2)and 90%(W3)of field capacity,respectively)and three N-fertilizer levels(i.e.0.18(N1),0.30(N2)and 0.42(N3)g/kg soil,respectively)were arranged with a randomized complete block design,and alternate partial root-zone irrigation method was applied.Results showed that fruit yields under deficit irrigation(W1 and W2)were decreased by 6.9%and 2.0%respectively compared with W3 under N1 level.Yields of tomato under W1N1 and W1N2 combinations were also reduced by 10.3%and 7.2%,respectively compared with W1N3 combination.Root dry weight,root length,root surface area and root volume were all increased in W1N2 treatment.According to two-way ANOVA,the root parameters except root dry weight,were extremely sensitive to water,nitrogen and the cross effect of the two factors.TSS(total soluble solids),SS(soluble sugars)and OA(organic acid)in the fruits increased with the decrease in irrigation water,OA and NC reduced with decreasing amount of nitrogen.Moreover,within an appropriate range,as more irrigation water and nitrogen were applied,the higher VC(vitamin C)and lycopene contents were identified in the fruits.Eventually,the combinational evaluation method(i.e.entropy method and gray relational analysis)showed that W2N2 ranked highest in comprehensive fruit quality.Therefore,considering the tradeoff between fruit comprehensive quality and yields,upper irrigation limitation of 80%θf and N-fertilizer of 0.30 g/kg soil with alternate partial root-zone irrigation was the optimal cultivation strategy for the greenhouse tomato in autumn-winter season in northwest China.展开更多
采用顶空-固相微萃取-气相色谱-嗅闻-质谱联用技术,结合感官分析和偏最小二乘回归(partial least squares regression,PLSR)分析方法,对热风干制过程中不同条件制备的7个红枣片样品特征香气活性化合物进行了测定及表征。结果表明,红枣...采用顶空-固相微萃取-气相色谱-嗅闻-质谱联用技术,结合感官分析和偏最小二乘回归(partial least squares regression,PLSR)分析方法,对热风干制过程中不同条件制备的7个红枣片样品特征香气活性化合物进行了测定及表征。结果表明,红枣片主要挥发性成分为19种酯类、15种酮类、15种酸类、12种醛类、9种醇类、6种烃类和2种呋喃类化合物。共识别出18种香气活性化合物气味活度值大于1,包括7种酮类、4种醛类、3种酯类、2种酸类、1种醇类和1种呋喃类物质。感官评价表明,经过热风干制的红枣片中主要特征香气为焦糖香、烤甜香、焦苦味和焦煳味。通过PLSR明确了感官属性与香气化合物之间的相关性:2,3-丁二酮和3-羟基-2-丁酮与烤甜香呈显著正相关;而γ-丁内酯、4-环戊烯-1,3-二酮和2,5-二甲基-4-羟基-3(2H)-呋喃酮对焦糖香有显著贡献;5-甲基呋喃醛和5-甲基-2(5H)-呋喃酮与焦苦味呈正相关;5-羟甲基呋喃醛是焦糊味特性的主要来源;3-羟基-2-甲基-4H-吡喃-4-酮、4H-吡喃-4-酮和2,3-二氢-3,5-二羟基-6-甲基与焦糊味及焦苦味都呈正相关。上述相关性均在感官评价员通过嗅闻仪闻到的具体味道中得到证实。展开更多
为改善中国毛虾盐度高、干瘪、鲜味差及虾体产生断头、黄圈等质量问题,该试验采用还原加盐法,盐水浓度2.5%、蒸煮时间4 m in、蒸煮温度98℃;采用间歇式二道烘干工艺,即先在75℃烘干20 m in后返潮15 m in,再进行二次70℃烘干20 m in;并采...为改善中国毛虾盐度高、干瘪、鲜味差及虾体产生断头、黄圈等质量问题,该试验采用还原加盐法,盐水浓度2.5%、蒸煮时间4 m in、蒸煮温度98℃;采用间歇式二道烘干工艺,即先在75℃烘干20 m in后返潮15 m in,再进行二次70℃烘干20 m in;并采用N2和CO2的比例为75%∶25%的混合气体结合BOPP/BOPA组合成的薄膜材料对虾皮进行保鲜包装。试验结果表明:研究的低盐度半脱水工艺可有效控制成品的低盐度,保持虾皮的鲜度和完整性;细菌总数以试验标准≤5×103cfu/g和国家标准≤1×104cfu/g衡量,合格率置信度分别为98.34%和99.99%,置信水平都为95%,制成品在常温下可保存6个月。展开更多
文摘Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the growth and production of maize(Zea mays L)in addition to the water use efficiency in soils with different gypsum content.The experimental treatments include three irrigation treatments,i.e.Conventional Irrigation(CI),Alternate Partial Root-zone Drying(APRD)and Fixed Partial Root-zone Drying(FPRD),and three soils with different gypsum content"(60.0[G1],153.7[G2],and 314.2[G3]g kg^(-1))".The vegetative growth,root dry mass and physiological indices(leaf relative water content,carotenoid concentration,proline)have been studied during three stages of maize plant growth(jointing,tasselling,and maturing).The Results showed that compared to CI,APRD and FPRD increased water use efficiency by 38.93 and 14.94%based on dry seed yield.In addition,compared to CI,APRD increased maize seed yield by 4.62-20.71%,while FPRD decreased yield by 19.24-5.28%for the gypsiferous soils G2 and G3,respectively.APRD has a slight effect on leaf water potential,leaf relative water content,carotenoid and proline activities from jointing to maturing stages at the three gypsiferous soils.Results suggest that APRD could make maize plants use water even more productively with better adaptation to water shortages in the gypsiferous soils.
基金supported by the National Natural Science Foundation of China(51809189)the Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources,China(2019002)。
文摘Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be considered as a water-saving strategy for greenhouse tomato production.
基金This work was supported by the National Natural Science Foundation of China(32071943,32272198).
文摘Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.
基金supported by the Beijing Natural Science Foundation,China (6102006)the New-Star of Science and Technology of Beijing Metropolis,China (2011051)
文摘Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water (D2O) in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.
基金funded by the Higher Education Commission of Pakistan(#20-4968/NRPU/R&D/HEC)
文摘Water is the main factor for the healthy life of plant.One of the main negative effects of climate change is the increasing scarcity of water that is lethal for plant.Globally,for water deficit regions(arid and semi-arid),drought is the main factor responsible for low production of agriculture,especially for cotton.Great efforts have been and are being made to find alternatives to water saving practices.This study aimed to examine the effects of partial rhizosphere drying(PRD,half of the root system irrigated at one event,and the other half irrigated in the next event,and so on)with and/or without various mulching treatments on physiological and biochemical traits of cotton.To explore this objective,we laid out experiments in completely randomized design with factorial arrangement in the Islamia University of Bahawalpur,Pakistan in 2016.Two factors included were four mulching treatments(M0,no mulching;M1,black plastic mulching;M2,wheat straw mulching;and M3,cotton sticks mulching)and two irrigation levels(I0,control(full irrigation);and I1,PRD).Fisher's analysis of variance among means of treatments was compared using least significant difference test at 5% probability level.Results revealed that the maximum plant height,leaf area,leaf gas exchange(photosynthetic rate and stomata conductance),chlorophyll,proline and total sugar contents,and enzyme activities were higher under M2 than under other three mulching treatments.As for irrigation levels,higher values of plant height,photosynthesis and water related parameters(leaf water potential,leaf osmotic potential,leaf turgor potential,etc.)were recorded.Contents of total sugar and proline and activities of antioxidant enzymes were significantly higher in PRD-treated plants than in control plants.It was concluded that combined application of PRD and mulching was more effective than the rest of the treatments used in the experiment.Similar study can be conducted in the field by applying irrigation water in alternate rows in semi-arid regions.
基金supported by the National Natural Science Foundation of China(30471197).
文摘To lay a biological foundation for rootstocks and alternate irrigation (AI) popularization, the effects of partial rootzone drying (PRD) on the growth of the grapevine Malvasia grafted on different rootstocks were investigated. Biological effects of 1/2 divided root irrigation on three combinations, i.e., Malvasia/420A, Malvasia/3309C, and Malvasia/110R, were studied by wood-boxed plants. All the plants were separated into three groups for different irrigation strategies. Mass growth of new root in alternate-irrigated plants was remarkably promoted by about 7.8-22.2% higher than the well- watered ones. However, new shoot growth, especially the internode was reduced by alternate irrigation. The average root-shoot ratio of all the three combinations was increased from 1.1 to 1.46. New root growth and internode length were decreased by fixed partial rootzone irrigation (FI) at different amount, M/3309C at 37.9 and 36.9%, M/110R at 18.4 and 22.5%, respectively. Total biomass of all the three combinations under FI decreased at the rate of 19.2-34.3% compared with well-watered ones. Water stress adaptation of grapevine mainly depends on rootstock. 110R is more efficient than 3309C and 420A in water stress adaptation. PRD-AI benefited root growth, thus improved the drought-resistant ability of grapevine.
文摘Partial Rootzone Drying (PRD) is an irrigation technique which offers a means of modifying the growth and development of crops through relatively simple changes to the method of water delivery. The technique causes the stimulation of physiological responses which are normally associated with water stress and this results in a significant reduction in water use through the production of chemical signals in drying roots. Partial drying of one half of the roots of plants grown with two root systems is rapidly translated into a reduction in transpiration and assimilation of all the crop leaves. The aim of this research is to examine and simulate the novel irrigation method (PRD), which would stimulate the endogenous stress response mechanisms of Conocarpus erectus trees in the pilot area of the Arabian Gulf University in Bahrain and wheat and maize crops in the Mashtul Pilot Area (MPA), Egypt using Saltmed model so that vigor is reduced and the efficiency of water use is enhanced. This is to be achieved by the manipulation of the hydration status of parts of a crop’s roots that could be used to control vegetative vigor without detrimental effects on canopy water relations. The PRD technique is researched for wheat as a winter crop and maize as a summer crop in Egypt. The technique causes the stimulation of physiological responses which are normally associated with water stress and this results in a significant reduction in water use through the production of chemical signals in drying roots. The results confirmed an increase in irrigation water use efficiency using PRD comparing with conventional flood irrigation. The research highly recommends applying the PRD method in the Gulf Cooperation Council (GCC) countries and in new reclaimed areas in Egypt to save water and improve crop quality.
基金supported by the National Natural Science Foundation of China(52066007,22279048)Yunnan Major Scientific and Technological Projects(202202AG050017)the Applied Basic Research Program of Yunnan Province(202101AT070076)。
文摘Redox catalysts play a vital role in the interconversion of two significant greenhouse gases,CO_(2)and CH_(4),via chemical looping methane dry reforming technology.Herein,a series of transition metals-alloyed and core-shell structured Ni-M/SiO_(2)@CeO_(2)(M=Fe,Co,Cu,Mn,Zr)redox catalyst were fabricated and evaluated in a gas-solid fixed-bed reactor for cycling CH_(4)partial oxidation(PO_(x))and CO_(2)splitting.The catalysts are composed of spherical SiO_(2)core and CeO_(2)shell,and the highly dispersed Ni alloy nanoparticles are the interlayer between core and shell.The oxygen vacancy concentration of Ni-M/SiO_(2)@CeO_(2)followed the order of Co>Cu>Fe>Mn>Zr,and Ni alloying with transition metals significantly enhanced oxygen storage capacity(OSC).Ni-Co/SiO_(2)@CeO_(2)catalyst with abundant oxygen vacancies and a high OSC showed the lowest temperatures of CH_(4)activation(610℃)and CO_(2)decomposition(590℃),thus demonstrating excellent redox reactivity.The catalyst exhibited superior activity and structural stability in the continuous CH_(4)/CO_(2)redox cycles at 615℃,achieving 87%CH_(4)conversion and 83%CO selectivity.The proposed catalyst shows great potential for the utilization of CH_(4)and CO_(2)in a redox mode,providing a new sight for design redox catalyst in chemical looping or related fields.
文摘Production of cocoa butter replacer (CBR) from tea seed oil through common modification methods of oils (dry fractionation, partial hydrogenation, chemical and enzymatic interesterification) was evaluated. Some physico-chemical properties (iodine, saponification, acid and peroxide values) and fatty acid composition (FAC) of modified samples were analyzed and compared with a reference cocoa butter (CB). Solid and liquid fractions for large amounts of unsaturated fatty acids (approx. 80%) and thereby lower iodine values (81 - 85 gI2/100g) than that of CB (37% and 34 gI2/100 g, respectively), are not suitable as CBR. Among all ratios of chemically and enzaymatically interesterified oil blends (20%, 25% and 30% of hydrogenated tea seed oil with 80%, 75% and 70% of tea seed oil/liquid fraction/solid fraction), the samples with ratio of 30:70 from both chemical and enzymatic interesterification had FAC and iodine value closer to that of CB. A comparision between chemically and enzymatically interesterified samples (CISs and EISs, respectively), in terms of solid fat content (SFC) indicated that although the SFC values in EIS were much lower than that of CB, but the thermal behavior of this sample is comprable to CB at 20℃- 30℃ (sharp melting point of CB).
基金This study was supported by National Natural Science Fund of China(51469010,51109102,51769010 and 51469003)Visiting Scholar Fund of Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education,Northwest A&F University.
文摘Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot experiments.There were four combinations of irrigation levels and growing stages of tomato for AI,i.e.AI_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,i.e.low urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of urea.Irrigation quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,respectively.Compared to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,respectively.AI_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)significantly.Compared to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,respectively.Compared to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,respectively.Therefore,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.
基金supported by the National Natural Science Fundation of China (51621061, 91425302) the 111 Program of Introducing Talents of Discipline to Universities (B14002)
文摘Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.
基金support from the National High-Tech 863 Project of China(2013AA103004)the program of Water Conservancy Science and Technology Plan of shaanxi Province(2014slkj-17).
文摘A pot experiment was conducted to investigate the effects of different water and nitrogen supply amounts on the comprehensive assessment of tomato fruit quality and root growth parameters under alternate partial root-zone irrigation.Three upper irrigation limitations(i.e.70%(W1),80%(W2)and 90%(W3)of field capacity,respectively)and three N-fertilizer levels(i.e.0.18(N1),0.30(N2)and 0.42(N3)g/kg soil,respectively)were arranged with a randomized complete block design,and alternate partial root-zone irrigation method was applied.Results showed that fruit yields under deficit irrigation(W1 and W2)were decreased by 6.9%and 2.0%respectively compared with W3 under N1 level.Yields of tomato under W1N1 and W1N2 combinations were also reduced by 10.3%and 7.2%,respectively compared with W1N3 combination.Root dry weight,root length,root surface area and root volume were all increased in W1N2 treatment.According to two-way ANOVA,the root parameters except root dry weight,were extremely sensitive to water,nitrogen and the cross effect of the two factors.TSS(total soluble solids),SS(soluble sugars)and OA(organic acid)in the fruits increased with the decrease in irrigation water,OA and NC reduced with decreasing amount of nitrogen.Moreover,within an appropriate range,as more irrigation water and nitrogen were applied,the higher VC(vitamin C)and lycopene contents were identified in the fruits.Eventually,the combinational evaluation method(i.e.entropy method and gray relational analysis)showed that W2N2 ranked highest in comprehensive fruit quality.Therefore,considering the tradeoff between fruit comprehensive quality and yields,upper irrigation limitation of 80%θf and N-fertilizer of 0.30 g/kg soil with alternate partial root-zone irrigation was the optimal cultivation strategy for the greenhouse tomato in autumn-winter season in northwest China.
文摘采用顶空-固相微萃取-气相色谱-嗅闻-质谱联用技术,结合感官分析和偏最小二乘回归(partial least squares regression,PLSR)分析方法,对热风干制过程中不同条件制备的7个红枣片样品特征香气活性化合物进行了测定及表征。结果表明,红枣片主要挥发性成分为19种酯类、15种酮类、15种酸类、12种醛类、9种醇类、6种烃类和2种呋喃类化合物。共识别出18种香气活性化合物气味活度值大于1,包括7种酮类、4种醛类、3种酯类、2种酸类、1种醇类和1种呋喃类物质。感官评价表明,经过热风干制的红枣片中主要特征香气为焦糖香、烤甜香、焦苦味和焦煳味。通过PLSR明确了感官属性与香气化合物之间的相关性:2,3-丁二酮和3-羟基-2-丁酮与烤甜香呈显著正相关;而γ-丁内酯、4-环戊烯-1,3-二酮和2,5-二甲基-4-羟基-3(2H)-呋喃酮对焦糖香有显著贡献;5-甲基呋喃醛和5-甲基-2(5H)-呋喃酮与焦苦味呈正相关;5-羟甲基呋喃醛是焦糊味特性的主要来源;3-羟基-2-甲基-4H-吡喃-4-酮、4H-吡喃-4-酮和2,3-二氢-3,5-二羟基-6-甲基与焦糊味及焦苦味都呈正相关。上述相关性均在感官评价员通过嗅闻仪闻到的具体味道中得到证实。
文摘为改善中国毛虾盐度高、干瘪、鲜味差及虾体产生断头、黄圈等质量问题,该试验采用还原加盐法,盐水浓度2.5%、蒸煮时间4 m in、蒸煮温度98℃;采用间歇式二道烘干工艺,即先在75℃烘干20 m in后返潮15 m in,再进行二次70℃烘干20 m in;并采用N2和CO2的比例为75%∶25%的混合气体结合BOPP/BOPA组合成的薄膜材料对虾皮进行保鲜包装。试验结果表明:研究的低盐度半脱水工艺可有效控制成品的低盐度,保持虾皮的鲜度和完整性;细菌总数以试验标准≤5×103cfu/g和国家标准≤1×104cfu/g衡量,合格率置信度分别为98.34%和99.99%,置信水平都为95%,制成品在常温下可保存6个月。