The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defi...The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.展开更多
Accurate and early evaluation of dental physiological characteristics is essential for effective disease detection and management.Polarization-sensitive optical coherence tomography(PS-OCT)is a noninvasive high-resolu...Accurate and early evaluation of dental physiological characteristics is essential for effective disease detection and management.Polarization-sensitive optical coherence tomography(PS-OCT)is a noninvasive high-resolution imaging technique that can obtain tooth structure and physiological features through intensity,retardation and degree of polarization uniformity(DOPU)images.In this study,we use the information provided by the PS-OCT system,especially the retardation information,to assess the physiological characteristics of teeth.In addition,we introduce a novel parameter—the rate of change of the retardation value(R)—to evaluate the magnitude of birefringence of enamel,which serves as an indicator of enamel health and mineralization.The results demonstrate that PS-OCT not only provides structural detail comparable to microcomputed tomography(microCT),but also yields additional physiological characteristics insights through polarization-based contrast.These findings highlight the strong potential of PS-OCT for early diagnosis,functional evaluation and personalized monitoring in dental care.展开更多
Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment ...Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment and physiological activities of tomato seedlings in seedbeds by controlled experiments.The results indicated that airflow could enhance CO_(2) concentration near the seedling canopy,accelerate water evaporation from the seedling substrate,and reduce fluctuations in the temperature and humidity in microclimate.The photosynthetic rates of leaves at the 4th,7th,and 10th positions in seedlings subjected to airflow increased by 25.04%,8.23%,and 8.47%,respectively,whereas the transpiration rates increased by 15.59%,22.28%,and 13.26%,respectively when compared to the control group.Additionally,the strong seedling index of seedlings treated with airflow and exogenous iron element increased by 26.02%and 31.5%,respectively.Compared to seedlings treated with exogenous iron element,the geometric mean diameter of the pith tissue cells in the stems of seedlings subjected to airflow disturbance was reduced by approximately 18.66%,while the elastic modulus and bending strength of the stems increased by 10.01%and 5.89%,respectively.Similarly,the volume of root tissue cells decreased by 19.22%,but the elastic modulus of the roots increased by 6.46%.This study confirms that airflow significantly enhances seedling resilience to abiotic stress,yielding similar or better outcomes than exogenous iron application.It provides both theoretical and practical support for using airflow disturbance as a green technology for cultivating robust seedlings.展开更多
Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the elec...Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.展开更多
Accurate detection of driver fatigue is essential for improving road safety.This study investigates the effectiveness of using multimodal physiological signals for fatigue detection while incorporating uncertainty qua...Accurate detection of driver fatigue is essential for improving road safety.This study investigates the effectiveness of using multimodal physiological signals for fatigue detection while incorporating uncertainty quantification to enhance the reliability of predictions.Physiological signals,including Electrocardiogram(ECG),Galvanic Skin Response(GSR),and Electroencephalogram(EEG),were transformed into image representations and analyzed using pretrained deep neu-ral networks.The extracted features were classified through a feedforward neural network,and prediction reliability was assessed using uncertainty quantification techniques such as Monte Carlo Dropout(MCD),model ensembles,and combined approaches.Evaluation metrics included standard measures(sensitivity,specificity,precision,and accuracy)along with uncertainty-aware metrics such as uncertainty sensitivity and uncertainty precision.Across all evaluations,ECG-based models consistently demonstrated strong performance.The findings indicate that combining multimodal physi-ological signals,Transfer Learning(TL),and uncertainty quantification can significantly improve both the accuracy and trustworthiness of fatigue detection systems.This approach supports the development of more reliable driver assistance technologies aimed at preventing fatigue-related accidents.展开更多
Morpho-physiological evaluation of a crop’s genetic resources is necessary to find possible genotypes to include in breeding initiatives.The objective of this study was to identify heat-tolerant wheat genotypes among...Morpho-physiological evaluation of a crop’s genetic resources is necessary to find possible genotypes to include in breeding initiatives.The objective of this study was to identify heat-tolerant wheat genotypes among 36 mutant lines using morpho-physiological indices.Seedlings of mutant lines and check varieties were grown under both normal(control)and heat-stress conditions in growth chambers.Data were recorded on root-shoot parameters(length,fresh weight,dry weight,and ratio),relative water content(RWC),stability of cell membrane,pigment content,and chlorophyll fluorescence.Two-way analysis of variance showed significant(p<0.01,p<0.001)variation among 15 morpho-physiological features in both growing conditions.Correlation studies showed that pigment-specific indices(total chl,chl a,chl b,carotenoid,Fv/Fm—chlorophyll fluorescence)had significant positive correlations with rootshoot fresh weight(RFW,SFW)and root-shoot dry weight(RDW,SDW),and negative association with relative water content,stability of cell membrane at both conditions.Hierarchical cluster analysis revealed three primary clusters where cluster III(18 genotypes)showed minimal changes in studied characters than cluster I(11 genotypes)and cluster II(13 genotypes).Results obtained from this study revealed that the identified heat-sensitive(30-2 SSH)and heat-tolerant genotypes(27-2(4),29-2(2),and 30-2 SSH)of wheat might provide useful breeding materials for enhancing wheat yield even more in this period of uncertain climate change.展开更多
Salinity stress is a major challenge for global agriculture,particularly in arid and semi-arid regions,limiting plant productivity due to water and soil salinity.These conditions particularly affect countries along th...Salinity stress is a major challenge for global agriculture,particularly in arid and semi-arid regions,limiting plant productivity due to water and soil salinity.These conditions particularly affect countries along the southern Mediterranean rim,including Algeria,which primarily focuses on pastoral and forage practices.This study investigates salinity tolerance and ecotypic variability in Vicia narbonensis L.,a fodder legume species recognized for its potential to reclaim marginal soils.Morphological,physiological,and biochemical responses were assessed in three ecotypes(eco2,eco9,and eco10)exposed to different salinity levels(low,moderate,and severe).The study was conducted using a completely randomized block design with three blocks per ecotype per dose.The results from the two-way analysis of variance demonstrate significant effects across nearly all attributes studied,revealing distinct ecotypic responses.These findings underscore variations in growth parameters,osmotic regulation mechanisms,and biochemical adjustments.The substantial diversity observed among these ecotypes in their response to salinity provides valuable insights for breeders addressing both agronomic and ecological challenges.Multivariate analyses,including Principal Component Analysis(PCA),revealed key variables distinguishing between ecotypes under salinity stress.Moreover,Classification based on Salinity Tolerance Indices(STI)further differentiated ecotypic performance with more precision,and this is because of the combination of the different parameters studied.These results open up new prospects for the development of strategies to improve the salinity tolerance of forage legumes.展开更多
[Objective] This study was conducted to investigate the morphological and physiological differences between the flowers opening spring and late autumn of Hosui Asian pear（Pyrus pyrifolia Nakai）. [Method] Pear flower...[Objective] This study was conducted to investigate the morphological and physiological differences between the flowers opening spring and late autumn of Hosui Asian pear（Pyrus pyrifolia Nakai）. [Method] Pear flowers were collected from normal bloom（NB） and returning bloom periods during late autumn in 2011-2013,respectively. The morphological and physiological indices including pollen number,germination rate, petal length, soluble protein content, soluble sugar content, amino acid content, pollen tube growth, fruiting characteristics of NB and RB flowers were detected and compared. [Result] The filament length and petal area of RB flowers were significantly smaller than those of NB flowers. The contents of soluble proteins, soluble sugars and amino acids of RB pollens were significantly smaller than those of NB flowers. In addition, the abortion rate of RB flowers was higher than that of NB flowers. [Conclusion] RB flowers had complete floral organs and were capable of pollination, but they were different from NB flowers in some morphological and physiological indices.展开更多
A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total le...A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total leaf area, and plant dry weight, but greatly increased density of root hairs and root top ratio. In addition, P-deficiency induced the significant enhancement of phosphorus utilization efficiency and the amount of proline, malondialdehye （MDA）, acid phosphatase （APase）, peroxidase （POD） and superoxide dismutase （SOD）, but the significant reduction of P uptake and soluable protein content. Since P-deficiency had smaller effects on the P-tolerant maize landraces DP-44, DP-32 and DP-33 as compared with P-sensitive landraces DP-29 and DP-24, it was demonstrated that differences of tolerance to P-deficiency existed among different maize landraces. The results based on the correlation analysis showed that the economic yield of maize landraces had relationships with their morphological and physiological characteristics under P-deficiency.展开更多
Response pattern was investigated for seedlings of Salix psammophila, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. The growth cha...Response pattern was investigated for seedlings of Salix psammophila, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. The growth characters, in terms of plant height, stem diameter, total branch number, total leaf number and area, total bifurcation ratio, total branch lenght and branch number, branch lenght, leaf number and leaf area of each branch order, and leaf, branch and root biomass significantly increased when water supply increased. That water supply had significant effect on biomass allocation showed different investment pattern of biomass resource of the seedlings grown under different water supply treatments. Stomatal density of abaxial leaf surface decreased, and stomatal apparatus length and width of adaxial and abaxial leaf surface increased with the increase of water supply, while Stomatal density of adaxial leaf surface was not affected by water supply. Water supply obviously affected the diumal changes of photosynthetic rate, and the photosynthetic rate of the seedlings showed strongly midday depression grown under the 157.5 mm water supply, but not grown under higher water supply. Additionally the assimilation-light response curves and flourescence efficiency more showed that water supply improve photosynthesis capacity. Finally, S. psammophila seedlings stood out by their slow growth and relatively high investments in root growth in order to reduce tissue losing rate and consumption of water resource for keeping water balance under water stress. The seedlings that grown under rich water supply did by their fast growth and relatively high investments in branch and leaf growth in order to improve the power of capturing light energy for higher photosynthesis.展开更多
The two mutants idr1-1 and 297-28, which were obtained from the radiation mutation of HD297 and IAPAR9, were used as experimental materials in this study for a 2-year(2012 and 2013) experiment about field drought resi...The two mutants idr1-1 and 297-28, which were obtained from the radiation mutation of HD297 and IAPAR9, were used as experimental materials in this study for a 2-year(2012 and 2013) experiment about field drought resistance identification in Beijing, China. Key agronomic traits and water-related physiological indexes were observed and measured, including the leaf anti-dead level(LADL), days to heading, plant height, setting percentage, aboveground biomass, leaf water potential(LWP), net photosynthetic rate(Pn) and transpiration rate. The results showed that the mutant idr1-1 that was under drought stress(DS) conditions for 2 years had the highest LADL grades(1.3 and 2.0) among all the materials, and they were 2–3 grades stronger than the wild-type IAPAR9 with an average that was 21.4% higher for the setting percentage than the wild type. Compared with the IAPAR9 for the 2-year average delay in the days to heading and the reduction rates in the plant height, setting percentage, and aboveground biomass under DS compared with the well-watered(WW) treatment, idr1-1 showed 3.2% less delay and 19.1, 16.4, and 6.1% less reduction, respectively. The idr1-1 in the LWP always exhibited the highest performance among all the materials. The Pn of idr1-1 under severe and mild DS comparing with that under WW was slightly decreased and even slightly increased, respectively, leading to an average reduction rate of only 0.92%, which was 26.93% less than that of IAPAR9. Under the severe DS, idr1-1 still showed the highest value of 16.88 μmol CO2 m–2 s–1 among all the materials and was significantly higher than that of IAPAR9(11.66 μmol CO2 m–2 s–1). Furthermore, only idr1-1 had the increased and the highest transpiration rate values(7.6 and 6.04 mmol H2 O m–2 s–1) under both mild and severe DS compared with the values under WW, when the transpiration rate of all the other materials significantly decreased. By contrast, the 297-28 in terms of the LADL grade under DS was the lowest(7.0), and it was four grades weaker than its wildtype HD297 and even one grade weaker than the drought-sensitive paddy rice SN265. For the 2-year average reduction rates in aboveground biomass and plant heights under DS compared with those under the WW, 297-28 was 31.6 and 31.8% higher than HD297, respectively. Meanwhile, 297-28 showed the worst performance for the LWP, Pn, and transpiration rate. These results suggest that idr1-1 might be a superior drought tolerant mutant of upland rice found in China. It has a strong ability to maintain and even enhance leaf transpiration while maintaining a high plant water potential under DS, thus supporting a high Pn and alleviating the delay in agronomic trait development and yield loss effectively. 297-28 is a much more highly drought-sensitive mutant that is even more sensitive than paddy rice varieties. The two mutants could be used as drought tolerance controls for rice germplasm identification and the drought resistant mechanism studies in the future. idr1-1 is also suitable for breeding drought-tolerant and lodging-resistant high-yield rice varieties.展开更多
The majority of rice(Oryza sativa L.) produced in the southern USA is drill-seeded and grown under upland-like conditions because permanent flooding is established after the four-leaf stage. Therefore, rice during the...The majority of rice(Oryza sativa L.) produced in the southern USA is drill-seeded and grown under upland-like conditions because permanent flooding is established after the four-leaf stage. Therefore, rice during the seedling growth stage will be subjected to variable soil moisture content. A greenhouse experiment was conducted to evaluate the performance of 15 rice cultivars commonly grown in Mississippi of USA under early-season soil moisture stress. Twenty morpho-physiological parameters of rice seedlings subjected to three different levels(100%, 66% and 33% field capacity) of soil moisture, from 10 to 30 d after sowing, were measured. Significant moisture stress × treatment interaction(P < 0.001) was observed for most of the parameters. Further, the total drought response index(TDRI) was developed to score the cultivars for drought tolerance with the variation from 26.88 to 36.21. Accordingly, the cultivars were classified into different groups of tolerance. The cultivars CL152 and CL142-AR were classified as the least and the most tolerant to drought based on TDRI and standard deviation, respectively. Even though both total root(R^2 = 0.98) or shoot(R^2 = 0.76) drought responses indices were positively correlated with TDRI, root traits were important in deriving the indices. Therefore, TDRI could be used to select cultivars for drought tolerance in a given environment and develop rice varieties with early-season drought tolerance. However, further research is needed to identify and characterize tolerance at other stages to assist breeding programs in rice.展开更多
financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;...financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）展开更多
Intercropping has been widely used in arid and semi-arid regions because of its high yield,stable productivity,and efficient utilization of resources.However,in recent years,the high yield of traditional intercropping...Intercropping has been widely used in arid and semi-arid regions because of its high yield,stable productivity,and efficient utilization of resources.However,in recent years,the high yield of traditional intercropping is mainly attributed to the large amount of purchased resources such as water and fertilizer,plastic film,and mechanical power.These lead to a decline in cultivated land quality and exacerbate intercrops'premature root and canopy senescence.So,the application of traditional intercropping faces major challenges in crop production.This paper analyzes the manifestations,occurrence mechanisms,and agronomic regulatory pathways of crop senescence.The physiological and ecological characteristics of intercropping to delay root and canopy senescence of crops are reviewed in this paper.The main agronomic regulatory pathways of intercropping to delay root and canopy senescence of crops are based on above-and blow-ground interactions,including collocation of crop varieties,spatial arrangement,water and fertilizer management,and tillage and mulch practices.Future research fields of intercropping to delay root and canopy senescence should focus on the aspects of selecting and breeding special varieties,application of molecular biology techniques,and developing or applying models to predict and evaluate the root and canopy senescence process of intercrops.Comprehensive analysis and evaluation of different research results could provide a basis for enhancing intercropping delay root and canopy senescence through adopting innovative technologies for regulating the physio-ecological characteristics of intercrops.This would support developing and adopting high-yield,efficient,and sustainable intercropping systems in arid and semi-arid areas with high population density,limited land,and abundant light and heat resources.展开更多
In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental ...In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental materials, potted and compared with CK by normal irrigation. Morphological indices such as plant height, stem diameter and physiological indices such as protein, soluble sugar, chlorophyll content and relative conductivity (REC) of the two varieties under drought stress at seedling stage, tillering stage and jointing stage were determined, and data statistics and variance analysis were performed for each index. The results showed that the morphological indices, plant height of Wenyi 4 and Wenyi 5 were significantly affected by drought stress at seedling stage, while the stem diameter was significantly affected by drought stress at seedling and jointing stage. In terms of physiological indices, the relative conductivity, protein and soluble sugar contents of Wenyi 5 increased at a higher degree, whereas chlorophyll content decreased at a higher degree, indicating that Wenyi 5 was greatly affected by drought stress. Through the analysis of drought resistance of the tested materials at different stages by polar ordination method, the results were as follows: jointing stage of Wenyi 5>jointing stage of Wenyi 4>seedling stage of Wenyi 4>seedling stage of Wenyi 5>tillering Stage of Wenyi 4>Tillering Stage of Wenyi 5. For the growth period, the drought resistance was as follows: jointing stage>seedling stage>tillering stage. In conclusion, Wenyi 4 has strong drought resistance and is suitable for droughtresistant cultivation.展开更多
Rice yield is heavily reliant on the number of spikelets per panicle,a factor determined by the processes of spikelet differentiation and degeneration.In rice cultivars with large panicles,spikelet degeneration negate...Rice yield is heavily reliant on the number of spikelets per panicle,a factor determined by the processes of spikelet differentiation and degeneration.In rice cultivars with large panicles,spikelet degeneration negates the advantages of large panicle and constrains yield potential.Environmental stress-induced metabolic disorders in plants aggravate spikelet degeneration,with the sensitive period for this process commencing approximately 15‒20 d before panicle heading.Notable positional variations occur within the panicle,with significantly higher spikelet degeneration rates at the basal than at the upper positions.An imbalance of carbon and nitrogen metabolism represents the primary physiological basis for aggravated spikelet degeneration under abiotic stress.Impaired carbon and nitrogen metabolism leads to disordered energy metabolism and disrupted respiratory electron transport,which accelerates the apoptosis of young spikelets through excessive reactive oxygen species accumulation.Sucrose serves as the main carbohydrate source for spikelet development,demonstrating an apical dominance pattern that favors spikelet formation.However,under abiotic stress,the inhibition of sucrose decomposition,rather than sucrose transport impairment,predominantly contributes to aggravated spikelet degeneration at the basal panicle positions.Brassinolide and auxin have a significant relationship with spikelet formation,potentially mediating apical dominance.Specifically,brassinolide enhances sucrose accumulation and utilization,thereby alleviating spikelet degeneration.At present,the mechanisms underlying rice spikelet degeneration have not been fully revealed,and the joint effects of hormones,carbohydrates,and carbon and nitrogen metabolism on this process require further investigation.To reduce the spikelet degeneration,the strategic application of water and fertilizer to establish a stable rice population can enhance the rice plants’resilience to abiotic stress.An effective approach to reducing spikelet degeneration is to increase the dry matter occupancy of each spikelet during the panicle initiation period.展开更多
Drought and salinity are the most widespread soil problems, posing a big threat to food security in rice growing regions. The present study evaluated the performance of eleven rice genotypes using morphological and ph...Drought and salinity are the most widespread soil problems, posing a big threat to food security in rice growing regions. The present study evaluated the performance of eleven rice genotypes using morphological and physiological parameters, under induced drought and salinity conditions. The seedlings were raised in 5 kg of homogenous soil in plastic bags in the </span><span style="font-family:Verdana;">greenhouse</span><span style="font-family:""><span style="font-family:Verdana;">. For the drought experiment, each bag was watered with 200 ml of water twice daily until plants reached the five-leaf stage when watering was suspended for 2 weeks for the drought stressed plants but not suspended for the control plants. The experiment was a 2 × 11 factorial and the set up was arranged using the completely randomized design with three replications. Data were taken on Plant height, Number of tillers, leaf length, Number of green leaves, Number of dead leaves, Leaf rolling score (LRS) and Rate of water loss. The salinity experiment was set up in a similar manner except that the plants were irrigated twice a day for 2 weeks with 200 ml of treatment solution containing either 0 mM NaCl or 75 mM and data were collected on plant height, number of tillers, shoot fresh weight, shoot dry weight, Na</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> and K</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> concentrations, relative water content and chlorophyll content. Data from both experiments were subjected to Analysis of variance test using the GenStat software 10</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> edition and the means separated using least significant difference test. Individual stress response index (ISRI) was calculated for each parameter and the means used in grouping the varieties. Of the genotypes evaluated, four (FARO 44, NERICA 2, NERICA 8 and NERICA 5) were identified as tolerant, two (NERICA 4 and FARO 57) as moderately tolerant, while the rest were found to be sensitive to drought. Equally, two varieties (FARO 44 and RAM 137) stood out in the salinity screening as tolerant varieties, five were moderately tolerant while four (FARO 64, FARO 52, NERICA 2 and FARO 55) were clearly susceptible. FARO 44 is the only genotype that </span><span style="font-family:Verdana;">showed </span></span><span style="font-family:Verdana;">tolerance</span><span style="font-family:""> </span><span style="font-family:Verdana;">to both drought and salinity. The identified drought and salinity tolerant rice genotypes from this study can be recommended as genetic sources for future breeding programs for drought and salinity </span><span style="font-family:Verdana;">tolerance</span><span style="font-family:""> </span><span style="font-family:Verdana;">in rice.展开更多
Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In...Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.展开更多
Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irriga...Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irrigation during the vegetative stages on soybean plants and determine the amount irrigation water can be reduced without affecting the physiological parameters,the crop phenology,and the yield of the soybean crop.The field experiments were conducted during two irrigation crop seasons(2021 and 2022)in Louata,Morocco.The results showed that regulated deficit irrigation regimes during the vegetative stages was combined with high temperatures and low air humidities during the beginning of flowering and the pod filling stage during 2021 in comparison with 2022,especially for 25%CWR(crop water requirements).Regulated deficit irrigation regimes reduced the stomatal conductance by 46%and 52%respectively during the first and second growing seasons by limiting CO_(2) intake for the Calvin cycle.The stomata closure increased the leaf temperature and affected the functioning of the photosynthetic apparatus by damaging the chlorophyll pigments and impairment of electron transport chains in chloroplasts.The transition from regulated deficit irrigation to 100%CWR at the beginning of flowering(R1)compensated for the photosynthetic loss,improved the growth and development of soybean plants and enhanced the yield and its components for 50%and 75%CWR.The adaptative mechanism such as the remobilization of the carbon reserved in the stems and leaves(vegetative tissues)to the grains improved the grain yield by 36.7%during 2021 and by 32.2%during 2022 and.This consequently improved the water use efficiency,the water productivity of soybean for 50%and 75%CWR and contributed to water saving with an average of 60 mm per growing season.展开更多
A possible scenario for the end of the 21st century is that the atmospheric CO2 concentration will be in the range of 510 - 760 μl·L-I and that the mean global temperature will be 1.5°C - 4.5&d...A possible scenario for the end of the 21st century is that the atmospheric CO2 concentration will be in the range of 510 - 760 μl·L-I and that the mean global temperature will be 1.5°C - 4.5°C higher than present day. One of the pre-eminent manifestations of climate change is the increase in atmospheric CO2 concentration. Both CO2 and temperature are the key variables of global climate and may cause significant changes in crop productivity. An experiment was conducted inside open top chamber (OTCs) in kharif season 2014 to evaluate the effects of CO2 enrichment and temperature rise with condition OTC1 (ambient condition), OTC2 (25% higher CO2 than ambient), OTC3 (25% higher CO2 + 2°C 】ambient temperature) and OTC4 (2°C 】ambient temperature) on physiological traits and yield of rice genotypes to identify the suitable genotypes for changing climatic conditions. The study revealed that rice genotypes performed better under elevated CO2, with slight changes in development, such as growth and in yield attributing traits, depending on the genotypes. However, the beneficial direct impact of elevated (CO2) on crop yield can be counteract by elevated temperatures. Rice genotype IR83376-B-B-24-2 was highly responsive while IR84895-B-127-CRA-5-1-1 was least responsive toward elevated CO2. Physiological traits like relative water content (RWC %), membrane stability index (MSI %), chlorophyll content, photosynthetic rate and TSS content were improved under elevated CO2. However, responses of these traits were negative with elevated temperature. We point out that studies related to changes in crop physiology and yield as a consequence of global climatic changes should be a priority due to their association with food security.展开更多
基金supported by the grants from the National Natural Science Foundation of China(32071843,31901444 and 31901445)the National Key Research and Development Program of China(2016YFD0300206-4 and 2018YFD0300800)+3 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)the Top Talent Supporting Program of Yangzhou University,China(2015-01)the Natural Science Foundation of Jiangsu Province,China(BK20190880)the Natural Science Foundation of Jiangsu Higher Education Institutions,China(19KJB210019)。
文摘The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.
基金supported by the National Natural Science Foundation of China(Nos.62375144 and 12404345)"the Fundamental Research Funds for the Central Universities",Nankai University(No.63241331).
文摘Accurate and early evaluation of dental physiological characteristics is essential for effective disease detection and management.Polarization-sensitive optical coherence tomography(PS-OCT)is a noninvasive high-resolution imaging technique that can obtain tooth structure and physiological features through intensity,retardation and degree of polarization uniformity(DOPU)images.In this study,we use the information provided by the PS-OCT system,especially the retardation information,to assess the physiological characteristics of teeth.In addition,we introduce a novel parameter—the rate of change of the retardation value(R)—to evaluate the magnitude of birefringence of enamel,which serves as an indicator of enamel health and mineralization.The results demonstrate that PS-OCT not only provides structural detail comparable to microcomputed tomography(microCT),but also yields additional physiological characteristics insights through polarization-based contrast.These findings highlight the strong potential of PS-OCT for early diagnosis,functional evaluation and personalized monitoring in dental care.
基金supported by an International Cooperation Key Plan of Shaanxi Province(Grant No.2022KWZ-12)an Agricultural Science Innovation and Transformation Project of Shaanxi Province[Grant No.NYKJ-2022-YL(XN)12]a High-End Foreign Expert Recruitment Program(Grant No.G2022172006L).
文摘Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment and physiological activities of tomato seedlings in seedbeds by controlled experiments.The results indicated that airflow could enhance CO_(2) concentration near the seedling canopy,accelerate water evaporation from the seedling substrate,and reduce fluctuations in the temperature and humidity in microclimate.The photosynthetic rates of leaves at the 4th,7th,and 10th positions in seedlings subjected to airflow increased by 25.04%,8.23%,and 8.47%,respectively,whereas the transpiration rates increased by 15.59%,22.28%,and 13.26%,respectively when compared to the control group.Additionally,the strong seedling index of seedlings treated with airflow and exogenous iron element increased by 26.02%and 31.5%,respectively.Compared to seedlings treated with exogenous iron element,the geometric mean diameter of the pith tissue cells in the stems of seedlings subjected to airflow disturbance was reduced by approximately 18.66%,while the elastic modulus and bending strength of the stems increased by 10.01%and 5.89%,respectively.Similarly,the volume of root tissue cells decreased by 19.22%,but the elastic modulus of the roots increased by 6.46%.This study confirms that airflow significantly enhances seedling resilience to abiotic stress,yielding similar or better outcomes than exogenous iron application.It provides both theoretical and practical support for using airflow disturbance as a green technology for cultivating robust seedlings.
文摘Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.
基金the Australian Research Council Discovery Projects funding scheme(DP190102181,DP210101465).
文摘Accurate detection of driver fatigue is essential for improving road safety.This study investigates the effectiveness of using multimodal physiological signals for fatigue detection while incorporating uncertainty quantification to enhance the reliability of predictions.Physiological signals,including Electrocardiogram(ECG),Galvanic Skin Response(GSR),and Electroencephalogram(EEG),were transformed into image representations and analyzed using pretrained deep neu-ral networks.The extracted features were classified through a feedforward neural network,and prediction reliability was assessed using uncertainty quantification techniques such as Monte Carlo Dropout(MCD),model ensembles,and combined approaches.Evaluation metrics included standard measures(sensitivity,specificity,precision,and accuracy)along with uncertainty-aware metrics such as uncertainty sensitivity and uncertainty precision.Across all evaluations,ECG-based models consistently demonstrated strong performance.The findings indicate that combining multimodal physi-ological signals,Transfer Learning(TL),and uncertainty quantification can significantly improve both the accuracy and trustworthiness of fatigue detection systems.This approach supports the development of more reliable driver assistance technologies aimed at preventing fatigue-related accidents.
文摘Morpho-physiological evaluation of a crop’s genetic resources is necessary to find possible genotypes to include in breeding initiatives.The objective of this study was to identify heat-tolerant wheat genotypes among 36 mutant lines using morpho-physiological indices.Seedlings of mutant lines and check varieties were grown under both normal(control)and heat-stress conditions in growth chambers.Data were recorded on root-shoot parameters(length,fresh weight,dry weight,and ratio),relative water content(RWC),stability of cell membrane,pigment content,and chlorophyll fluorescence.Two-way analysis of variance showed significant(p<0.01,p<0.001)variation among 15 morpho-physiological features in both growing conditions.Correlation studies showed that pigment-specific indices(total chl,chl a,chl b,carotenoid,Fv/Fm—chlorophyll fluorescence)had significant positive correlations with rootshoot fresh weight(RFW,SFW)and root-shoot dry weight(RDW,SDW),and negative association with relative water content,stability of cell membrane at both conditions.Hierarchical cluster analysis revealed three primary clusters where cluster III(18 genotypes)showed minimal changes in studied characters than cluster I(11 genotypes)and cluster II(13 genotypes).Results obtained from this study revealed that the identified heat-sensitive(30-2 SSH)and heat-tolerant genotypes(27-2(4),29-2(2),and 30-2 SSH)of wheat might provide useful breeding materials for enhancing wheat yield even more in this period of uncertain climate change.
基金Direction Generale de la Recherche Scientifique et du Developpement Technologique(DGRSDT)Algeria,and the Researchers Supporting Project No.(RSP2025R390),King Saud University,Riyadh,Saudi Arabia.
文摘Salinity stress is a major challenge for global agriculture,particularly in arid and semi-arid regions,limiting plant productivity due to water and soil salinity.These conditions particularly affect countries along the southern Mediterranean rim,including Algeria,which primarily focuses on pastoral and forage practices.This study investigates salinity tolerance and ecotypic variability in Vicia narbonensis L.,a fodder legume species recognized for its potential to reclaim marginal soils.Morphological,physiological,and biochemical responses were assessed in three ecotypes(eco2,eco9,and eco10)exposed to different salinity levels(low,moderate,and severe).The study was conducted using a completely randomized block design with three blocks per ecotype per dose.The results from the two-way analysis of variance demonstrate significant effects across nearly all attributes studied,revealing distinct ecotypic responses.These findings underscore variations in growth parameters,osmotic regulation mechanisms,and biochemical adjustments.The substantial diversity observed among these ecotypes in their response to salinity provides valuable insights for breeders addressing both agronomic and ecological challenges.Multivariate analyses,including Principal Component Analysis(PCA),revealed key variables distinguishing between ecotypes under salinity stress.Moreover,Classification based on Salinity Tolerance Indices(STI)further differentiated ecotypic performance with more precision,and this is because of the combination of the different parameters studied.These results open up new prospects for the development of strategies to improve the salinity tolerance of forage legumes.
基金Supported by Sichuan Provincial Program on Basic Research Project(15JC0096)~~
文摘[Objective] This study was conducted to investigate the morphological and physiological differences between the flowers opening spring and late autumn of Hosui Asian pear（Pyrus pyrifolia Nakai）. [Method] Pear flowers were collected from normal bloom（NB） and returning bloom periods during late autumn in 2011-2013,respectively. The morphological and physiological indices including pollen number,germination rate, petal length, soluble protein content, soluble sugar content, amino acid content, pollen tube growth, fruiting characteristics of NB and RB flowers were detected and compared. [Result] The filament length and petal area of RB flowers were significantly smaller than those of NB flowers. The contents of soluble proteins, soluble sugars and amino acids of RB pollens were significantly smaller than those of NB flowers. In addition, the abortion rate of RB flowers was higher than that of NB flowers. [Conclusion] RB flowers had complete floral organs and were capable of pollination, but they were different from NB flowers in some morphological and physiological indices.
文摘A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total leaf area, and plant dry weight, but greatly increased density of root hairs and root top ratio. In addition, P-deficiency induced the significant enhancement of phosphorus utilization efficiency and the amount of proline, malondialdehye （MDA）, acid phosphatase （APase）, peroxidase （POD） and superoxide dismutase （SOD）, but the significant reduction of P uptake and soluable protein content. Since P-deficiency had smaller effects on the P-tolerant maize landraces DP-44, DP-32 and DP-33 as compared with P-sensitive landraces DP-29 and DP-24, it was demonstrated that differences of tolerance to P-deficiency existed among different maize landraces. The results based on the correlation analysis showed that the economic yield of maize landraces had relationships with their morphological and physiological characteristics under P-deficiency.
文摘Response pattern was investigated for seedlings of Salix psammophila, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. The growth characters, in terms of plant height, stem diameter, total branch number, total leaf number and area, total bifurcation ratio, total branch lenght and branch number, branch lenght, leaf number and leaf area of each branch order, and leaf, branch and root biomass significantly increased when water supply increased. That water supply had significant effect on biomass allocation showed different investment pattern of biomass resource of the seedlings grown under different water supply treatments. Stomatal density of abaxial leaf surface decreased, and stomatal apparatus length and width of adaxial and abaxial leaf surface increased with the increase of water supply, while Stomatal density of adaxial leaf surface was not affected by water supply. Water supply obviously affected the diumal changes of photosynthetic rate, and the photosynthetic rate of the seedlings showed strongly midday depression grown under the 157.5 mm water supply, but not grown under higher water supply. Additionally the assimilation-light response curves and flourescence efficiency more showed that water supply improve photosynthesis capacity. Finally, S. psammophila seedlings stood out by their slow growth and relatively high investments in root growth in order to reduce tissue losing rate and consumption of water resource for keeping water balance under water stress. The seedlings that grown under rich water supply did by their fast growth and relatively high investments in branch and leaf growth in order to improve the power of capturing light energy for higher photosynthesis.
基金supported by the National Key Research and Development Program of China(2016YFD0100101)the 948 Program of China(2006-G51)the European Commission within the 6th Framework Program(ECFP6)INCO-2003-B1.2(CEDROME-015468)
文摘The two mutants idr1-1 and 297-28, which were obtained from the radiation mutation of HD297 and IAPAR9, were used as experimental materials in this study for a 2-year(2012 and 2013) experiment about field drought resistance identification in Beijing, China. Key agronomic traits and water-related physiological indexes were observed and measured, including the leaf anti-dead level(LADL), days to heading, plant height, setting percentage, aboveground biomass, leaf water potential(LWP), net photosynthetic rate(Pn) and transpiration rate. The results showed that the mutant idr1-1 that was under drought stress(DS) conditions for 2 years had the highest LADL grades(1.3 and 2.0) among all the materials, and they were 2–3 grades stronger than the wild-type IAPAR9 with an average that was 21.4% higher for the setting percentage than the wild type. Compared with the IAPAR9 for the 2-year average delay in the days to heading and the reduction rates in the plant height, setting percentage, and aboveground biomass under DS compared with the well-watered(WW) treatment, idr1-1 showed 3.2% less delay and 19.1, 16.4, and 6.1% less reduction, respectively. The idr1-1 in the LWP always exhibited the highest performance among all the materials. The Pn of idr1-1 under severe and mild DS comparing with that under WW was slightly decreased and even slightly increased, respectively, leading to an average reduction rate of only 0.92%, which was 26.93% less than that of IAPAR9. Under the severe DS, idr1-1 still showed the highest value of 16.88 μmol CO2 m–2 s–1 among all the materials and was significantly higher than that of IAPAR9(11.66 μmol CO2 m–2 s–1). Furthermore, only idr1-1 had the increased and the highest transpiration rate values(7.6 and 6.04 mmol H2 O m–2 s–1) under both mild and severe DS compared with the values under WW, when the transpiration rate of all the other materials significantly decreased. By contrast, the 297-28 in terms of the LADL grade under DS was the lowest(7.0), and it was four grades weaker than its wildtype HD297 and even one grade weaker than the drought-sensitive paddy rice SN265. For the 2-year average reduction rates in aboveground biomass and plant heights under DS compared with those under the WW, 297-28 was 31.6 and 31.8% higher than HD297, respectively. Meanwhile, 297-28 showed the worst performance for the LWP, Pn, and transpiration rate. These results suggest that idr1-1 might be a superior drought tolerant mutant of upland rice found in China. It has a strong ability to maintain and even enhance leaf transpiration while maintaining a high plant water potential under DS, thus supporting a high Pn and alleviating the delay in agronomic trait development and yield loss effectively. 297-28 is a much more highly drought-sensitive mutant that is even more sensitive than paddy rice varieties. The two mutants could be used as drought tolerance controls for rice germplasm identification and the drought resistant mechanism studies in the future. idr1-1 is also suitable for breeding drought-tolerant and lodging-resistant high-yield rice varieties.
基金funded by Mississippi Rice Promotion Board and United States Department of AgricultureNational Institute of Food and Agriculture(USDA-NIFA,Grant No.2013-34263-20931)sub-award to Mississippi State University(Grant No.G-7799-2)
文摘The majority of rice(Oryza sativa L.) produced in the southern USA is drill-seeded and grown under upland-like conditions because permanent flooding is established after the four-leaf stage. Therefore, rice during the seedling growth stage will be subjected to variable soil moisture content. A greenhouse experiment was conducted to evaluate the performance of 15 rice cultivars commonly grown in Mississippi of USA under early-season soil moisture stress. Twenty morpho-physiological parameters of rice seedlings subjected to three different levels(100%, 66% and 33% field capacity) of soil moisture, from 10 to 30 d after sowing, were measured. Significant moisture stress × treatment interaction(P < 0.001) was observed for most of the parameters. Further, the total drought response index(TDRI) was developed to score the cultivars for drought tolerance with the variation from 26.88 to 36.21. Accordingly, the cultivars were classified into different groups of tolerance. The cultivars CL152 and CL142-AR were classified as the least and the most tolerant to drought based on TDRI and standard deviation, respectively. Even though both total root(R^2 = 0.98) or shoot(R^2 = 0.76) drought responses indices were positively correlated with TDRI, root traits were important in deriving the indices. Therefore, TDRI could be used to select cultivars for drought tolerance in a given environment and develop rice varieties with early-season drought tolerance. However, further research is needed to identify and characterize tolerance at other stages to assist breeding programs in rice.
基金financed by the Special Program of Super Rice of Ministry of Agriculture, China (02318802013231)the National Public Services Sectors (Agricultural) Research Projects, Ministry of Agriculture, China (201303102)the Great Technology Project of Ningbo, China (2013C11001)
文摘financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）
基金supported by the National Natural Science Foundation of China(32101857 and U21A20218)the China Agricultural University Corresponding Support Research Joint Fund(GSAU-DKZY-2024-001)+1 种基金the Science and Technology Program in Gansu Province,China(24ZDNA008and23JRRA1407)the Fuxi Young Talents Fund of Gansu Agricultural University,China(Gaufx-03Y10).
文摘Intercropping has been widely used in arid and semi-arid regions because of its high yield,stable productivity,and efficient utilization of resources.However,in recent years,the high yield of traditional intercropping is mainly attributed to the large amount of purchased resources such as water and fertilizer,plastic film,and mechanical power.These lead to a decline in cultivated land quality and exacerbate intercrops'premature root and canopy senescence.So,the application of traditional intercropping faces major challenges in crop production.This paper analyzes the manifestations,occurrence mechanisms,and agronomic regulatory pathways of crop senescence.The physiological and ecological characteristics of intercropping to delay root and canopy senescence of crops are reviewed in this paper.The main agronomic regulatory pathways of intercropping to delay root and canopy senescence of crops are based on above-and blow-ground interactions,including collocation of crop varieties,spatial arrangement,water and fertilizer management,and tillage and mulch practices.Future research fields of intercropping to delay root and canopy senescence should focus on the aspects of selecting and breeding special varieties,application of molecular biology techniques,and developing or applying models to predict and evaluate the root and canopy senescence process of intercrops.Comprehensive analysis and evaluation of different research results could provide a basis for enhancing intercropping delay root and canopy senescence through adopting innovative technologies for regulating the physio-ecological characteristics of intercrops.This would support developing and adopting high-yield,efficient,and sustainable intercropping systems in arid and semi-arid areas with high population density,limited land,and abundant light and heat resources.
文摘In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental materials, potted and compared with CK by normal irrigation. Morphological indices such as plant height, stem diameter and physiological indices such as protein, soluble sugar, chlorophyll content and relative conductivity (REC) of the two varieties under drought stress at seedling stage, tillering stage and jointing stage were determined, and data statistics and variance analysis were performed for each index. The results showed that the morphological indices, plant height of Wenyi 4 and Wenyi 5 were significantly affected by drought stress at seedling stage, while the stem diameter was significantly affected by drought stress at seedling and jointing stage. In terms of physiological indices, the relative conductivity, protein and soluble sugar contents of Wenyi 5 increased at a higher degree, whereas chlorophyll content decreased at a higher degree, indicating that Wenyi 5 was greatly affected by drought stress. Through the analysis of drought resistance of the tested materials at different stages by polar ordination method, the results were as follows: jointing stage of Wenyi 5>jointing stage of Wenyi 4>seedling stage of Wenyi 4>seedling stage of Wenyi 5>tillering Stage of Wenyi 4>Tillering Stage of Wenyi 5. For the growth period, the drought resistance was as follows: jointing stage>seedling stage>tillering stage. In conclusion, Wenyi 4 has strong drought resistance and is suitable for droughtresistant cultivation.
基金funded by the National Natural Science Foundation of China(Grant No.32201896)the Zhejiang Province Key Research and Development Plan Project,China(Grant No.2022C02034)the National Modern Agricultural Industrial Technology System Construction Project,China(Grant No.CARS-01-21).
文摘Rice yield is heavily reliant on the number of spikelets per panicle,a factor determined by the processes of spikelet differentiation and degeneration.In rice cultivars with large panicles,spikelet degeneration negates the advantages of large panicle and constrains yield potential.Environmental stress-induced metabolic disorders in plants aggravate spikelet degeneration,with the sensitive period for this process commencing approximately 15‒20 d before panicle heading.Notable positional variations occur within the panicle,with significantly higher spikelet degeneration rates at the basal than at the upper positions.An imbalance of carbon and nitrogen metabolism represents the primary physiological basis for aggravated spikelet degeneration under abiotic stress.Impaired carbon and nitrogen metabolism leads to disordered energy metabolism and disrupted respiratory electron transport,which accelerates the apoptosis of young spikelets through excessive reactive oxygen species accumulation.Sucrose serves as the main carbohydrate source for spikelet development,demonstrating an apical dominance pattern that favors spikelet formation.However,under abiotic stress,the inhibition of sucrose decomposition,rather than sucrose transport impairment,predominantly contributes to aggravated spikelet degeneration at the basal panicle positions.Brassinolide and auxin have a significant relationship with spikelet formation,potentially mediating apical dominance.Specifically,brassinolide enhances sucrose accumulation and utilization,thereby alleviating spikelet degeneration.At present,the mechanisms underlying rice spikelet degeneration have not been fully revealed,and the joint effects of hormones,carbohydrates,and carbon and nitrogen metabolism on this process require further investigation.To reduce the spikelet degeneration,the strategic application of water and fertilizer to establish a stable rice population can enhance the rice plants’resilience to abiotic stress.An effective approach to reducing spikelet degeneration is to increase the dry matter occupancy of each spikelet during the panicle initiation period.
文摘Drought and salinity are the most widespread soil problems, posing a big threat to food security in rice growing regions. The present study evaluated the performance of eleven rice genotypes using morphological and physiological parameters, under induced drought and salinity conditions. The seedlings were raised in 5 kg of homogenous soil in plastic bags in the </span><span style="font-family:Verdana;">greenhouse</span><span style="font-family:""><span style="font-family:Verdana;">. For the drought experiment, each bag was watered with 200 ml of water twice daily until plants reached the five-leaf stage when watering was suspended for 2 weeks for the drought stressed plants but not suspended for the control plants. The experiment was a 2 × 11 factorial and the set up was arranged using the completely randomized design with three replications. Data were taken on Plant height, Number of tillers, leaf length, Number of green leaves, Number of dead leaves, Leaf rolling score (LRS) and Rate of water loss. The salinity experiment was set up in a similar manner except that the plants were irrigated twice a day for 2 weeks with 200 ml of treatment solution containing either 0 mM NaCl or 75 mM and data were collected on plant height, number of tillers, shoot fresh weight, shoot dry weight, Na</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> and K</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> concentrations, relative water content and chlorophyll content. Data from both experiments were subjected to Analysis of variance test using the GenStat software 10</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> edition and the means separated using least significant difference test. Individual stress response index (ISRI) was calculated for each parameter and the means used in grouping the varieties. Of the genotypes evaluated, four (FARO 44, NERICA 2, NERICA 8 and NERICA 5) were identified as tolerant, two (NERICA 4 and FARO 57) as moderately tolerant, while the rest were found to be sensitive to drought. Equally, two varieties (FARO 44 and RAM 137) stood out in the salinity screening as tolerant varieties, five were moderately tolerant while four (FARO 64, FARO 52, NERICA 2 and FARO 55) were clearly susceptible. FARO 44 is the only genotype that </span><span style="font-family:Verdana;">showed </span></span><span style="font-family:Verdana;">tolerance</span><span style="font-family:""> </span><span style="font-family:Verdana;">to both drought and salinity. The identified drought and salinity tolerant rice genotypes from this study can be recommended as genetic sources for future breeding programs for drought and salinity </span><span style="font-family:Verdana;">tolerance</span><span style="font-family:""> </span><span style="font-family:Verdana;">in rice.
基金supported by the National Natural Science Foundation of China(52127801)Postdoctoral Fellowship Program of CPSF under Grant Number GZC20231545,China Postdoctoral Science Foundation(2024T170557 and 2023M742224)+1 种基金Shanghai Post-doctoral Excellence Program(No.2023440)City University of Hong Kong Donation Grants(DON-RMG No.9229021 and 9220061).
文摘Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.
基金financially supported by Domaine Louata of Providence Verte Company,Agricultural Training and Research Center.
文摘Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irrigation during the vegetative stages on soybean plants and determine the amount irrigation water can be reduced without affecting the physiological parameters,the crop phenology,and the yield of the soybean crop.The field experiments were conducted during two irrigation crop seasons(2021 and 2022)in Louata,Morocco.The results showed that regulated deficit irrigation regimes during the vegetative stages was combined with high temperatures and low air humidities during the beginning of flowering and the pod filling stage during 2021 in comparison with 2022,especially for 25%CWR(crop water requirements).Regulated deficit irrigation regimes reduced the stomatal conductance by 46%and 52%respectively during the first and second growing seasons by limiting CO_(2) intake for the Calvin cycle.The stomata closure increased the leaf temperature and affected the functioning of the photosynthetic apparatus by damaging the chlorophyll pigments and impairment of electron transport chains in chloroplasts.The transition from regulated deficit irrigation to 100%CWR at the beginning of flowering(R1)compensated for the photosynthetic loss,improved the growth and development of soybean plants and enhanced the yield and its components for 50%and 75%CWR.The adaptative mechanism such as the remobilization of the carbon reserved in the stems and leaves(vegetative tissues)to the grains improved the grain yield by 36.7%during 2021 and by 32.2%during 2022 and.This consequently improved the water use efficiency,the water productivity of soybean for 50%and 75%CWR and contributed to water saving with an average of 60 mm per growing season.
文摘A possible scenario for the end of the 21st century is that the atmospheric CO2 concentration will be in the range of 510 - 760 μl·L-I and that the mean global temperature will be 1.5°C - 4.5°C higher than present day. One of the pre-eminent manifestations of climate change is the increase in atmospheric CO2 concentration. Both CO2 and temperature are the key variables of global climate and may cause significant changes in crop productivity. An experiment was conducted inside open top chamber (OTCs) in kharif season 2014 to evaluate the effects of CO2 enrichment and temperature rise with condition OTC1 (ambient condition), OTC2 (25% higher CO2 than ambient), OTC3 (25% higher CO2 + 2°C 】ambient temperature) and OTC4 (2°C 】ambient temperature) on physiological traits and yield of rice genotypes to identify the suitable genotypes for changing climatic conditions. The study revealed that rice genotypes performed better under elevated CO2, with slight changes in development, such as growth and in yield attributing traits, depending on the genotypes. However, the beneficial direct impact of elevated (CO2) on crop yield can be counteract by elevated temperatures. Rice genotype IR83376-B-B-24-2 was highly responsive while IR84895-B-127-CRA-5-1-1 was least responsive toward elevated CO2. Physiological traits like relative water content (RWC %), membrane stability index (MSI %), chlorophyll content, photosynthetic rate and TSS content were improved under elevated CO2. However, responses of these traits were negative with elevated temperature. We point out that studies related to changes in crop physiology and yield as a consequence of global climatic changes should be a priority due to their association with food security.
