Mariculture tailwater poses significant environmental challenges such as water pollution and eutrophication.Photosynthetic bacteria(PSB)have been widely used for pollutant treatment.The integrated aquaculture wastewat...Mariculture tailwater poses significant environmental challenges such as water pollution and eutrophication.Photosynthetic bacteria(PSB)have been widely used for pollutant treatment.The integrated aquaculture wastewater bioremediation system(IAWBS)consists of four key components:sedimentation,biofilm,shellfish,and macro-algae.However,there is still some room for improvement in the treatment efficiency of the IAWBS.In this study,PSB(Rhodopseudomonos,Rhodobacteria,Rhodococcus)were added to the system.High-throughput amplicon of 16S rRNA,PERMANOVA,NMDS and other statistical analyses were used to investigate the impacts of PSB.The results showed that significant removal efficiencies of CODMn,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,PO_(4)^(3-)-P were 71.42%,91.37%,91.72%,87.20%,and 88.80%,respectively.The impact of PSB on bacterioplankton community(BC)was not affected by the time interval but affected by different units,Proteobacteria,Bacteriodia and Actinobacteria were the most abundant phyla in all the units.Alpha diversity underscored a significant decrease in bacterial community diversity due to the PSB.Notably,the PERMANOVA analysis highlighted a significant interaction between the time interval and treated unit,influencing the composition of the microbial community(R^(2)=0.152;P=0.001).This study provides a better understanding of the role of photosynthetic bacteria in an integrated bioremediation system that can effectively treat mariculture tailwater,which is of great significance for the sustainable development of aquaculture.展开更多
Saline treatment is a low-cost,simple,and effective method to stimulate astaxanthin accumulation in Haematococcus pluvialis,and is proposed to be applied in the second stage of a 2-stage culture since it does not nece...Saline treatment is a low-cost,simple,and effective method to stimulate astaxanthin accumulation in Haematococcus pluvialis,and is proposed to be applied in the second stage of a 2-stage culture since it does not necessitate changing the medium.To understand the effect of salinity on the astaxanthin production of H.pluvialis,the photosynthetic activity and the biocomponents production in 1-and 2-stage cultures in different salinities were investigated.Except for astaxanthin synthesis,which increased at low salinities of 2 and 5-g/L NaCl,most biocomponent yields decreased in 1-stage cultures as salinity increased.At a salinity of 5-g/L NaCl,the 2-stage culture further increased astaxanthin production to 18.41±0.24 mg/L,which was more than 2.0 times that of the control.Saline treatment led to an overall decrease in photosynthetic performance indices of H.pluvialis,and had an impact on five sites of the electron transport chain:the energy connection between antenna and reaction center of photosystemⅡ(PSⅡ),oxygen evolving complex activity on the donor side,the electron transfer from plastoquinone A(Q_(A))to plastoquinone B(Q_(B))and from plastoquinone(PQ)to receptor side of photosystem I(PS I),and the pool size of the end electron acceptors in PSⅠacceptor side.The excitation imbalance between PSⅠand PSⅡcaused by the variance in the electron transfer chain necessitated the synthesis of antioxidants like astaxanthin in order to ensure cell viability.The accumulation of astaxanthin was found to be closely correlated with the stabilized or enhanced the maximum relative electron transfer rate(rETR_(max))and the PSⅡactual quantum yield(QY_(SS))as well as the increased fluorescence yield at J-step(V_(J)).This work offers the novel insight of how saline stress controls H.pluvialis photosynthetic activity and astaxanthin synthesis.展开更多
Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological infor...Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.展开更多
This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluor...This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluorescence parameters of M.spectabilis‘Hongjiu’seedlings under O_(3)stress were measured by spraying different concentrations of MeJA.The results showed that O_(3)stress significantly reduced the chlorophyll a and total chlorophyll content,net photosynthetic rate(Pn),stomatal conductance(G_(s)),transpiration rate(T_(r)),maximum fluorescence yield(F_(m)),maximum quantum yield of photosystem II(F_(v)/F_(m)),and actual photochemical efficiency of photosystem II(Ф_(PSII)),while increasing the intercellular CO_(2)concentration(Ci).Exogenous MeJA reduced the Ci and original fluorescence yield(Fo),while increasing chlorophyll a,chlorophyll b,and total chlorophyll content,P_(n),G_(s),T_(r),F_(m),F_(v)/F_(m),andФ_(PSII) of the leaves under O_(3)stress.The application of 150μmol/L MeJA showed the best effect.The above results demonstrated that exogenous MeJA could enhance chlorophyll content and photosynthetic capacity,thereby improving the tolerance of M.spectabilis to O_(3)stress.展开更多
The net primary productivity(NPP)of forest ecosystems plays a crucial role in regulating the terrestrial carbon cycle under global climate change.While the temporal effect driven by ecosystem processes on NPP variatio...The net primary productivity(NPP)of forest ecosystems plays a crucial role in regulating the terrestrial carbon cycle under global climate change.While the temporal effect driven by ecosystem processes on NPP variations is well-documented,spatial variations(from local to regional scales)remain inadequately understood.To evaluate the scale-dependent effects of productivity,predictions from the Biome-BGC model were compared with moderate-resolution imaging spectroradiometer(MODIS)and biometric NPP data in a large temperate forest region at both local and regional levels.Linear mixed-effect models and variance partitioning analysis were used to quantify the effects of environmental heterogeneity and trait variation on simulated NPP at varying spatial scales.Results show that NPP had considerable predictability at the local scale,with a coefficient of determination(R^(2))of 0.37,but this predictability declined significantly to 0.02 at the regional scale.Environmental heterogeneity and photosynthetic traits collectively explained 94.8%of the local variation in NPP,which decreased to 86.7%regionally due to the reduced common effects among these variables.Locally,the leaf area index(LAI)predominated(34.6%),while at regional scales,the stomatal conductance and maximum carboxylation rate were more influential(41.1%).Our study suggests that environmental heterogeneity drives the photosynthetic processes that mediate NPP variations across spatial scales.Incorporating heterogeneous local conditions and trait variations into analyses could enhance future research on the relationship between climate and carbon cycles at larger scales.展开更多
Salt stress severely limits rice growth and productivity.Auxin signaling has a well-documented role in development,but its role in rice salt stress responses is far from clear.In this study,we identified OsARF12,an au...Salt stress severely limits rice growth and productivity.Auxin signaling has a well-documented role in development,but its role in rice salt stress responses is far from clear.In this study,we identified OsARF12,an auxin response factor,as a critical positive regulator of salt tolerance in rice.Transcript analysis revealed salt-induced upregulation of OsARF12.More importantly,OsARF12 overexpression(OsARF12-OX)induced significantly increased survival rates and reduced biomass loss under 200 mmol L^(−1)NaCl treatment compared with wild-type(WT)plants,and OsARF12 knockout(OsARF12-KO)using CRISPR-Cas9 showed the opposite tendency.Physiological analyses revealed that OsARF12-OX plants mitigated salt-induced oxidative damage by enhancing ROS scavenging capacity and promoting Na^(+)/K^(+)homeostasis as well as through their superior photosynthetic efficiency under 200 mmol L^(−1)NaCl treatment,which was consistent with the upregulation of differentially expressed genes involved in ROS scavenging,photosynthesis and ion transport pathways.Furthermore,auxin receptor genes or transcription inhibitor genes were upregulated or downregulated in OsARF12-OX lines compared with WT plants under salt stress,respectively.Biochemical assays indicated that OsARF12 acts as a transcriptional activator,directly binding to TGTC-box motifs in the promoters of the key ion transporters OsSOS1 and OsHKT1;5 to reduce shoot Na^(+)content and the Na^(^(+))/K^(+)ratio,thereby increasing salt tolerance.These findings revealed the potential role of OsARF12 in increasing salt tolerance by integrating auxin signaling with ROS scavenging,ionic homeostasis and photosynthetic networks,offering valuable targets for breeding resilient rice varieties.展开更多
Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilati...Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilation.However,the spatio-temporal patterns of climatic constraints and seasonal carbon assimilation are poorly understood.In this study,the timing of peak photosynthetic activity(DOY_(pmax))was employed as a proxy for plant adap-tive state to climatic constraints on growth to examine the spatio-temporal dynamics of DOY_(pmax).By using multiple remote sensing metrics,DOY_(pmax)was characterized with changes in the solar-induced chlorophyll fluorescence(SIF)and leaf area index(LAI)from 2000 to 2018.Based on SIF,the DOY_(pmax)was generally around day 190,while based on LAI was about 10 d later.Peak photosynthetic activity of forests occurs earlier compared to other vegetation types.Overall,the advanced DOY_(pmax)were observed based on both SIF and LAI,with annual rates of 0.2(P=0.31)and 0.3(P<0.05)d,respectively.DOY_(pmax)dynamics were influ-enced by hot temperature extremes and vapor pressure defi-cits(VPD)during the early growing season,regardless of sub-zone and different vegetation type.The generalized lin-ear mixed model(GLMM)showed the largest contribution by hot extremes to DOY_(pmax)dynamics accounted for 55.5%(DOY_(pmax_SIF))and 49.1%(DOY_(pmax_LAI)),respectively,fol-lowed by VPD(DOY_(pmax_SIF):23.1%;DOY_(pmax_LAI):29.5%).These findings highlight the crucial role of climate extremes in shaping seasonal carbon dynamics and regional carbon balance.展开更多
Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocat...Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.展开更多
Straw return has demonstrated significant potential for enhancing carbon(C)sequestration and nitrogen(N)uptake while concurrently promoting plant productivity.However,the specific transport and distribution of C produ...Straw return has demonstrated significant potential for enhancing carbon(C)sequestration and nitrogen(N)uptake while concurrently promoting plant productivity.However,the specific transport and distribution of C produced by photosynthesis and exogenous N within the rice plant-soil system under straw return remains unclear.A long-term straw return pot trial experiment was conducted in a double cropping rice system,incorporating treatments of inorganic fertilizer application with straw removal(F),straw burning and ash return with reducing inorganic fertilizers(SBR),and straw return with reducing inorganic fertilizers(SR)to investigate C sequestration and exogenous N uptake using ^(13)C pulse and ^(15)N isotope tracer techniques.The SR treatment had significantly higher soil ^(13)C abundance,by 24.4 and 25.4%,respectively,^(13)C concentrations in aboveground plant parts,by 18.4 and 35.8%respectively,and ^(15)N concentrations in rice panicles,by 12.8 and 34.3%than the SBR and F treatments.This enhancement contributed to a higher total organic C concentration and increased rice grain yield in the SR treatment.Furthermore,the SR treatment had significantly higher photosynthetic C,by 9.8%,which was directly transferred to soil C.The SR treatment had a higher distribution of photosynthetic C in the leaves and stems,but a lower distribution in the panicle compared to the SBR treatment.This finding is advantageous for sequestering photosynthetic C into the soil through straw return;conversely,opposite trends were observed in ^(15)N distribution.In addition,rice plants in the SR treatment had increased N uptake from urea and soil N sources,enhancing N recovery by 9.2 and 12.5%,respectively,and reducing soil N residues.Correlation analysis showed that the SR treatment increased the concentrations of ^(13)C in leaves and roots while decreasing the ^(15)N abundance in all rice organs,thereby contributing to an increase in rice yield.The partial least square path model suggested that the increase in rice yield under the SR treatment was primarily linked to ^(13)C accumulation within the rice plant-soil system.The results suggest that straw return increases the sequestration of photosynthetic C and exogenous N in the rice plant-soil system and increases N utilization efficiency,which subsequently improves both rice and soil productivity.展开更多
It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their...It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their photosynthetic structures (leaves) and non-photosynthetic structures (branches and stem) is unknown. The purpose of this study is to test the hypotheses that: (1) the above-ground parts of plants have functional equilibriums between their photosynthetic structures and non-photosynthetic structures; (2) the maintenance of the equilibriums is guaranteed by the alteration of biomass partitioning to photosynthetic and non-photosynthetic structures. To test these hypotheses, a pruning experiment with four pruning intensities (0%, 20%, 50%, and 70%) were carried out with three subtropical Chinese tree species ( Ficus microcarpa, Ficus virens, Cinnamomum camphora). Pruning treatments were conducted in two successive years. The results were in conformity with the hypothesis, i.e. above-ground parts of trees had functional equilibriums between photosynthetic and non-photosynthetic structures. Pruning decreased instantaneously the mass ratios of photosynthetic structures to non-photosynthetic structures (P/NP) of all three tree species, the reduction in P/NP was strengthened with pruning intensity. However, one year after pruning, the P/NP of all pruned trees increased and were not smaller than those of unpruned trees. In agreement with the expectation, the biomass partitioning of pruned trees was altered, more newly produced above-ground biomass was partitioned to leaf growth and less to branch and stem growth, thus enabled the damaged trees to restore their functional equilibrium between photosynthetic and non-photosynthetic structures. It is clear that the maintenance of functional equilibrium between photosynthetic and non-photosynthetic structures guaranteed by the alteration of biomass partitioning provides plants a good strategy to resist external disturbance and damage.展开更多
The photosynthetic functions and the sensitivity to photoinhibition were compared between two superhigh_yield hybrid rice (Oryza sativa L.) Liangyoupeijiu and X07S/Zihui 100, the newly developed from two parental line...The photosynthetic functions and the sensitivity to photoinhibition were compared between two superhigh_yield hybrid rice (Oryza sativa L.) Liangyoupeijiu and X07S/Zihui 100, the newly developed from two parental lines and traditional hybrid rice Shanyou 63 developed from three parental lines. The results showed that, as compared to Shanyou 63, the net photosynthetic rate of Liangyoupeijiu and X07S/Zihui 100 was 9.1% and 11.9% higher, the transpiration rate was 37.4% and 31.4% lower, and their water use efficiency was 74.2% and 63.5% higher respectively. After strong light (2 000 μmol photons·m -2 ·s -1 ) treatment for 2 h, the photochemical quantum yield and the photochemical quenching increased by 37.0% and 18.0% respectively in Liangyoupeijiu, 28.3% and 46.2% in X07S/Zihui 100, but decreased a little in Shanyou 63. The non_photochemical quenching decreased in Liangyoupeijiu and X07S/Zihui 100 (about 50%) but increased greatly in Shanyou 63 (about 50%). Better photosynthetic functions, higher water use efficiency and stronger resistance to photoinhibition, may be the physiological basis for the super high_yield of the two hybrid rice under study.展开更多
Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductan...Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation.展开更多
Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) in...Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) increased by 30% - 40% in comparison with the cultivars with normal photosynthetic efficiency, indicating that the breeding of soybean by increasing RPE may have a bright prospect. HPE breeding can be used as the temporal monitoring in the breeding process to avoid the divergency of the predetermined goal, although HPE breeding does not shorten the breeding time. It was observed that limited C-4 pathway exists in soybean leaf and pod, suggesting that by increasing the genetic expression of some C-4 enzymes in C-3 crops through traditional or genetic engineering techniques, new breakthroughs in increasing the photosynthetic efficiency of C-3 plant may be practicable in the future.展开更多
Four winter wheat (Triticum aestivum L.) varieties ('JD 8', 'Jing 411','Centurk' and 'Tam 202') were used to study the effect of heat stress on photosynthetic characteristics of flag le...Four winter wheat (Triticum aestivum L.) varieties ('JD 8', 'Jing 411','Centurk' and 'Tam 202') were used to study the effect of heat stress on photosynthetic characteristics of flag leaf blade, nag leaf sheath, peduncle, glume, lemma and awn during grain-filling stage. The results showed that heat acclimation during grain-filling stage increased thermotolerance of wheat with significant differences among different green organs. During heat stress, the decreases of the efficiency of primary light energy conversion (F-v/F-m) of PS II and pigment (chlorophyll and carotenoid) content were much slower in peduncle, flag leaf sheath and glume than in nag leaf blade, lemma and ann; and the percentage of decrease in net photosynthetic rate (P-n) of ear was lower than that of the nag leaf blade. The measured photosynthetic parameters (F-v/F-m, P-n and pigment content) of 'JD 8', a relatively heat tolerant variety, declined more slowly than those of the other three varieties during the whole heat stress period.展开更多
[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditi...[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditions. [ Result] A respective single peak at 11：30 was observed in diurnal variation curves of net photosynthetic rate （Pn） and transpiration rate（Tr）. Correlation analysis shows that Pn presents an extremely significant correlation with photon flux densities （PFD） of photosynthetically active radiation, in comparison assumes a significant correlation either with stomatal conductance （Gs） or with ambient CO2 concentration （Ca）. [ Conclusion] Gs followed by PFD presented most influence on Pn of super high-yield combination C Liangyou H255.展开更多
The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the...The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.展开更多
To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,...To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...展开更多
[Objective] The aim was to evaluate the effects of different concentrations of ABA on photosynthetic characteristics of pods and yield of Brassica napus and analyze the relationships between ABA concentration and yiel...[Objective] The aim was to evaluate the effects of different concentrations of ABA on photosynthetic characteristics of pods and yield of Brassica napus and analyze the relationships between ABA concentration and yield components, to provide theoretical basis for cultivation of high-yield rapeseed. [Method] At the end of flowering stage, the rape plants were separately sprayed with 1, 2, 100 and 200μmol/L of ABA; photosynthetic parameters, water use efficiency （WUE）, yield and yield components of the rape plants were investigated 0, 5, 10 and 15 d later, respectively. [Result] ABA treatment with different concentrations significantly changed pod photosynthetic parameters and yield components of rapeseed. Low concentra- tions of ABA could improve pod＇s net photosynthetic rate and yield components while high concentrations had the contrary effect. [Conclusion] Whether ABA func- tioned in inhibiting or promoting role might depend on the interaction between endogenous hormone levels and exogenous ABA concentration. Improvement of WUE would be the main reason for yield increasing.展开更多
[Objective] The aim of this study is to understand the high yield often photosynthetic mechanism of super hybrid rice P88S/0389.[Method] Chlorophyll and carotenoid contents were measured via the method of Wellburn and...[Objective] The aim of this study is to understand the high yield often photosynthetic mechanism of super hybrid rice P88S/0389.[Method] Chlorophyll and carotenoid contents were measured via the method of Wellburn and Lichtenthaler,and the photosynthetic rate and chlorophyll fluorescence parameters were measured using portable photosynthesis system.Through comparison of above measured indices between P88S/0389 and its parents,the photosynthetic characteristics were obtained.[Result] The pigment content of P88S/0389 lied between their parents,and detailedly was closer to its female parent at earlier growth stage and to its male parent at latter stage,respectively.The Pn,Fv/Fo,Fv/Fm and qP of the flag leaf of P88S/0389 were all higher than those of its parents,while the degradation rates of these parameters were slower than those of its parents.The qN of flag leaf was lower than those of its parents,and the increasing rate of qN of P88S/0389 was also slower than those of its parents,indicating the great heterosis of P88S/0389 to its parents in photosynthetic capacity.The data show that P88S/0389 is endowed with stronger capacities in light energy absorption,transformation and carbon fixation compared to its parents.[Conclusion] The light energy absorbed by hybrid mainly contributes to photochemical reaction,and little for heat dissipation.For ensuring high yield,the rice cultivars selected for production should synchronously possess higher photosynthetic rate and longer high value duration.展开更多
[Objective] The aim was to explore the photosynthetic characteristics of Turpan grapes under high temperature and strong light conditions. [Method] Using six grape varieties as experimental materials, the photosynthes...[Objective] The aim was to explore the photosynthetic characteristics of Turpan grapes under high temperature and strong light conditions. [Method] Using six grape varieties as experimental materials, the photosynthesis and fluorescence parameters of the grape varieties under high temperature and high light were determined. [Result] The results showed that Thompson Seedless showed strong selfprotection ability on the photosynthetic mechanism in the adversity, and lower photo inhibition on photosynthesis under high temperature and high light than other varieties in which Crimson Seedless was second place. Otherwise the damage on photosynthetic mechanism of Kyoho and Red Globe under the adversity environment is more dipper than the other varieties, and poor self-protection ability. [Conclusion]Thompson Seedless and Crimson Seedless had a strong adaptability for high temperature and strong light. But the adaptability of Kyoho and Red Globe were relatively poor.展开更多
基金financially supported by the National Key R&D Program of China(No.2020YFD0900201)the Ningbo Public Welfare Technology Application Research Project(No.2022S164)the K.C.Wong Magna Fund in Ningbo University。
文摘Mariculture tailwater poses significant environmental challenges such as water pollution and eutrophication.Photosynthetic bacteria(PSB)have been widely used for pollutant treatment.The integrated aquaculture wastewater bioremediation system(IAWBS)consists of four key components:sedimentation,biofilm,shellfish,and macro-algae.However,there is still some room for improvement in the treatment efficiency of the IAWBS.In this study,PSB(Rhodopseudomonos,Rhodobacteria,Rhodococcus)were added to the system.High-throughput amplicon of 16S rRNA,PERMANOVA,NMDS and other statistical analyses were used to investigate the impacts of PSB.The results showed that significant removal efficiencies of CODMn,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,PO_(4)^(3-)-P were 71.42%,91.37%,91.72%,87.20%,and 88.80%,respectively.The impact of PSB on bacterioplankton community(BC)was not affected by the time interval but affected by different units,Proteobacteria,Bacteriodia and Actinobacteria were the most abundant phyla in all the units.Alpha diversity underscored a significant decrease in bacterial community diversity due to the PSB.Notably,the PERMANOVA analysis highlighted a significant interaction between the time interval and treated unit,influencing the composition of the microbial community(R^(2)=0.152;P=0.001).This study provides a better understanding of the role of photosynthetic bacteria in an integrated bioremediation system that can effectively treat mariculture tailwater,which is of great significance for the sustainable development of aquaculture.
基金Supported by the National Natural Science Foundation of China(Nos.42177459,41776156,41271521)。
文摘Saline treatment is a low-cost,simple,and effective method to stimulate astaxanthin accumulation in Haematococcus pluvialis,and is proposed to be applied in the second stage of a 2-stage culture since it does not necessitate changing the medium.To understand the effect of salinity on the astaxanthin production of H.pluvialis,the photosynthetic activity and the biocomponents production in 1-and 2-stage cultures in different salinities were investigated.Except for astaxanthin synthesis,which increased at low salinities of 2 and 5-g/L NaCl,most biocomponent yields decreased in 1-stage cultures as salinity increased.At a salinity of 5-g/L NaCl,the 2-stage culture further increased astaxanthin production to 18.41±0.24 mg/L,which was more than 2.0 times that of the control.Saline treatment led to an overall decrease in photosynthetic performance indices of H.pluvialis,and had an impact on five sites of the electron transport chain:the energy connection between antenna and reaction center of photosystemⅡ(PSⅡ),oxygen evolving complex activity on the donor side,the electron transfer from plastoquinone A(Q_(A))to plastoquinone B(Q_(B))and from plastoquinone(PQ)to receptor side of photosystem I(PS I),and the pool size of the end electron acceptors in PSⅠacceptor side.The excitation imbalance between PSⅠand PSⅡcaused by the variance in the electron transfer chain necessitated the synthesis of antioxidants like astaxanthin in order to ensure cell viability.The accumulation of astaxanthin was found to be closely correlated with the stabilized or enhanced the maximum relative electron transfer rate(rETR_(max))and the PSⅡactual quantum yield(QY_(SS))as well as the increased fluorescence yield at J-step(V_(J)).This work offers the novel insight of how saline stress controls H.pluvialis photosynthetic activity and astaxanthin synthesis.
基金funded by the National Key Research and Development Program of China(No.20022YFC3102405)the National Natural Science Foundation of China(Nos.42425004,32371665)the Natural Science Foundation of Guangdong Province(Nos.2022A1515011461,2022A1515011831)。
文摘Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.
文摘This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluorescence parameters of M.spectabilis‘Hongjiu’seedlings under O_(3)stress were measured by spraying different concentrations of MeJA.The results showed that O_(3)stress significantly reduced the chlorophyll a and total chlorophyll content,net photosynthetic rate(Pn),stomatal conductance(G_(s)),transpiration rate(T_(r)),maximum fluorescence yield(F_(m)),maximum quantum yield of photosystem II(F_(v)/F_(m)),and actual photochemical efficiency of photosystem II(Ф_(PSII)),while increasing the intercellular CO_(2)concentration(Ci).Exogenous MeJA reduced the Ci and original fluorescence yield(Fo),while increasing chlorophyll a,chlorophyll b,and total chlorophyll content,P_(n),G_(s),T_(r),F_(m),F_(v)/F_(m),andФ_(PSII) of the leaves under O_(3)stress.The application of 150μmol/L MeJA showed the best effect.The above results demonstrated that exogenous MeJA could enhance chlorophyll content and photosynthetic capacity,thereby improving the tolerance of M.spectabilis to O_(3)stress.
基金supported by the National Key R&D Program of China(No.2023YFF1304001-01)the Science and Technology Project of the Department of Transportation of Heilongjiang Province(No.HJK2023B024-3)the Program of National Natural Science Foundation of China(No.32371870).
文摘The net primary productivity(NPP)of forest ecosystems plays a crucial role in regulating the terrestrial carbon cycle under global climate change.While the temporal effect driven by ecosystem processes on NPP variations is well-documented,spatial variations(from local to regional scales)remain inadequately understood.To evaluate the scale-dependent effects of productivity,predictions from the Biome-BGC model were compared with moderate-resolution imaging spectroradiometer(MODIS)and biometric NPP data in a large temperate forest region at both local and regional levels.Linear mixed-effect models and variance partitioning analysis were used to quantify the effects of environmental heterogeneity and trait variation on simulated NPP at varying spatial scales.Results show that NPP had considerable predictability at the local scale,with a coefficient of determination(R^(2))of 0.37,but this predictability declined significantly to 0.02 at the regional scale.Environmental heterogeneity and photosynthetic traits collectively explained 94.8%of the local variation in NPP,which decreased to 86.7%regionally due to the reduced common effects among these variables.Locally,the leaf area index(LAI)predominated(34.6%),while at regional scales,the stomatal conductance and maximum carboxylation rate were more influential(41.1%).Our study suggests that environmental heterogeneity drives the photosynthetic processes that mediate NPP variations across spatial scales.Incorporating heterogeneous local conditions and trait variations into analyses could enhance future research on the relationship between climate and carbon cycles at larger scales.
基金funded by National Natural Science Foundation of China(NSFC 32272014)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(25IRTSTHN030)+2 种基金Henan Provincial Science and Technology Research Project(252102111144)the Key Laboratory of Functional Agriculture of Guizhou Province([2023]007)the Key Laboratory of Molecular Breeding for Grain and Oil Crops of Guizhou Province([2023]008).
文摘Salt stress severely limits rice growth and productivity.Auxin signaling has a well-documented role in development,but its role in rice salt stress responses is far from clear.In this study,we identified OsARF12,an auxin response factor,as a critical positive regulator of salt tolerance in rice.Transcript analysis revealed salt-induced upregulation of OsARF12.More importantly,OsARF12 overexpression(OsARF12-OX)induced significantly increased survival rates and reduced biomass loss under 200 mmol L^(−1)NaCl treatment compared with wild-type(WT)plants,and OsARF12 knockout(OsARF12-KO)using CRISPR-Cas9 showed the opposite tendency.Physiological analyses revealed that OsARF12-OX plants mitigated salt-induced oxidative damage by enhancing ROS scavenging capacity and promoting Na^(+)/K^(+)homeostasis as well as through their superior photosynthetic efficiency under 200 mmol L^(−1)NaCl treatment,which was consistent with the upregulation of differentially expressed genes involved in ROS scavenging,photosynthesis and ion transport pathways.Furthermore,auxin receptor genes or transcription inhibitor genes were upregulated or downregulated in OsARF12-OX lines compared with WT plants under salt stress,respectively.Biochemical assays indicated that OsARF12 acts as a transcriptional activator,directly binding to TGTC-box motifs in the promoters of the key ion transporters OsSOS1 and OsHKT1;5 to reduce shoot Na^(+)content and the Na^(^(+))/K^(+)ratio,thereby increasing salt tolerance.These findings revealed the potential role of OsARF12 in increasing salt tolerance by integrating auxin signaling with ROS scavenging,ionic homeostasis and photosynthetic networks,offering valuable targets for breeding resilient rice varieties.
基金supported by the National Key R&D Program of China(2021YFD2200405)the National Natural Science Foundationof China(Nos.U23A2002,31930078,and 31670450)the Fundamental Research Funds for ICBR(1632021023,1632019006,and1630032023002).
文摘Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilation.However,the spatio-temporal patterns of climatic constraints and seasonal carbon assimilation are poorly understood.In this study,the timing of peak photosynthetic activity(DOY_(pmax))was employed as a proxy for plant adap-tive state to climatic constraints on growth to examine the spatio-temporal dynamics of DOY_(pmax).By using multiple remote sensing metrics,DOY_(pmax)was characterized with changes in the solar-induced chlorophyll fluorescence(SIF)and leaf area index(LAI)from 2000 to 2018.Based on SIF,the DOY_(pmax)was generally around day 190,while based on LAI was about 10 d later.Peak photosynthetic activity of forests occurs earlier compared to other vegetation types.Overall,the advanced DOY_(pmax)were observed based on both SIF and LAI,with annual rates of 0.2(P=0.31)and 0.3(P<0.05)d,respectively.DOY_(pmax)dynamics were influ-enced by hot temperature extremes and vapor pressure defi-cits(VPD)during the early growing season,regardless of sub-zone and different vegetation type.The generalized lin-ear mixed model(GLMM)showed the largest contribution by hot extremes to DOY_(pmax)dynamics accounted for 55.5%(DOY_(pmax_SIF))and 49.1%(DOY_(pmax_LAI)),respectively,fol-lowed by VPD(DOY_(pmax_SIF):23.1%;DOY_(pmax_LAI):29.5%).These findings highlight the crucial role of climate extremes in shaping seasonal carbon dynamics and regional carbon balance.
文摘Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.
基金supported by the National Natural Science Foundation of China(32160503)the Earmarked Fund for Jiangxi Agriculture Research System,China(JXARS-01)the National Key R&D Program of China(2023YFD2301303).
文摘Straw return has demonstrated significant potential for enhancing carbon(C)sequestration and nitrogen(N)uptake while concurrently promoting plant productivity.However,the specific transport and distribution of C produced by photosynthesis and exogenous N within the rice plant-soil system under straw return remains unclear.A long-term straw return pot trial experiment was conducted in a double cropping rice system,incorporating treatments of inorganic fertilizer application with straw removal(F),straw burning and ash return with reducing inorganic fertilizers(SBR),and straw return with reducing inorganic fertilizers(SR)to investigate C sequestration and exogenous N uptake using ^(13)C pulse and ^(15)N isotope tracer techniques.The SR treatment had significantly higher soil ^(13)C abundance,by 24.4 and 25.4%,respectively,^(13)C concentrations in aboveground plant parts,by 18.4 and 35.8%respectively,and ^(15)N concentrations in rice panicles,by 12.8 and 34.3%than the SBR and F treatments.This enhancement contributed to a higher total organic C concentration and increased rice grain yield in the SR treatment.Furthermore,the SR treatment had significantly higher photosynthetic C,by 9.8%,which was directly transferred to soil C.The SR treatment had a higher distribution of photosynthetic C in the leaves and stems,but a lower distribution in the panicle compared to the SBR treatment.This finding is advantageous for sequestering photosynthetic C into the soil through straw return;conversely,opposite trends were observed in ^(15)N distribution.In addition,rice plants in the SR treatment had increased N uptake from urea and soil N sources,enhancing N recovery by 9.2 and 12.5%,respectively,and reducing soil N residues.Correlation analysis showed that the SR treatment increased the concentrations of ^(13)C in leaves and roots while decreasing the ^(15)N abundance in all rice organs,thereby contributing to an increase in rice yield.The partial least square path model suggested that the increase in rice yield under the SR treatment was primarily linked to ^(13)C accumulation within the rice plant-soil system.The results suggest that straw return increases the sequestration of photosynthetic C and exogenous N in the rice plant-soil system and increases N utilization efficiency,which subsequently improves both rice and soil productivity.
文摘It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their photosynthetic structures (leaves) and non-photosynthetic structures (branches and stem) is unknown. The purpose of this study is to test the hypotheses that: (1) the above-ground parts of plants have functional equilibriums between their photosynthetic structures and non-photosynthetic structures; (2) the maintenance of the equilibriums is guaranteed by the alteration of biomass partitioning to photosynthetic and non-photosynthetic structures. To test these hypotheses, a pruning experiment with four pruning intensities (0%, 20%, 50%, and 70%) were carried out with three subtropical Chinese tree species ( Ficus microcarpa, Ficus virens, Cinnamomum camphora). Pruning treatments were conducted in two successive years. The results were in conformity with the hypothesis, i.e. above-ground parts of trees had functional equilibriums between photosynthetic and non-photosynthetic structures. Pruning decreased instantaneously the mass ratios of photosynthetic structures to non-photosynthetic structures (P/NP) of all three tree species, the reduction in P/NP was strengthened with pruning intensity. However, one year after pruning, the P/NP of all pruned trees increased and were not smaller than those of unpruned trees. In agreement with the expectation, the biomass partitioning of pruned trees was altered, more newly produced above-ground biomass was partitioned to leaf growth and less to branch and stem growth, thus enabled the damaged trees to restore their functional equilibrium between photosynthetic and non-photosynthetic structures. It is clear that the maintenance of functional equilibrium between photosynthetic and non-photosynthetic structures guaranteed by the alteration of biomass partitioning provides plants a good strategy to resist external disturbance and damage.
基金The State Key Basic Research and Development Plan(G1998010100)The Innovative Foundation of Laboratory of Photosynthesis Basic Research,Insitute of Botany,The Chinese Academy of Sciences
文摘The photosynthetic functions and the sensitivity to photoinhibition were compared between two superhigh_yield hybrid rice (Oryza sativa L.) Liangyoupeijiu and X07S/Zihui 100, the newly developed from two parental lines and traditional hybrid rice Shanyou 63 developed from three parental lines. The results showed that, as compared to Shanyou 63, the net photosynthetic rate of Liangyoupeijiu and X07S/Zihui 100 was 9.1% and 11.9% higher, the transpiration rate was 37.4% and 31.4% lower, and their water use efficiency was 74.2% and 63.5% higher respectively. After strong light (2 000 μmol photons·m -2 ·s -1 ) treatment for 2 h, the photochemical quantum yield and the photochemical quenching increased by 37.0% and 18.0% respectively in Liangyoupeijiu, 28.3% and 46.2% in X07S/Zihui 100, but decreased a little in Shanyou 63. The non_photochemical quenching decreased in Liangyoupeijiu and X07S/Zihui 100 (about 50%) but increased greatly in Shanyou 63 (about 50%). Better photosynthetic functions, higher water use efficiency and stronger resistance to photoinhibition, may be the physiological basis for the super high_yield of the two hybrid rice under study.
文摘Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation.
文摘Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) increased by 30% - 40% in comparison with the cultivars with normal photosynthetic efficiency, indicating that the breeding of soybean by increasing RPE may have a bright prospect. HPE breeding can be used as the temporal monitoring in the breeding process to avoid the divergency of the predetermined goal, although HPE breeding does not shorten the breeding time. It was observed that limited C-4 pathway exists in soybean leaf and pod, suggesting that by increasing the genetic expression of some C-4 enzymes in C-3 crops through traditional or genetic engineering techniques, new breakthroughs in increasing the photosynthetic efficiency of C-3 plant may be practicable in the future.
文摘Four winter wheat (Triticum aestivum L.) varieties ('JD 8', 'Jing 411','Centurk' and 'Tam 202') were used to study the effect of heat stress on photosynthetic characteristics of flag leaf blade, nag leaf sheath, peduncle, glume, lemma and awn during grain-filling stage. The results showed that heat acclimation during grain-filling stage increased thermotolerance of wheat with significant differences among different green organs. During heat stress, the decreases of the efficiency of primary light energy conversion (F-v/F-m) of PS II and pigment (chlorophyll and carotenoid) content were much slower in peduncle, flag leaf sheath and glume than in nag leaf blade, lemma and ann; and the percentage of decrease in net photosynthetic rate (P-n) of ear was lower than that of the nag leaf blade. The measured photosynthetic parameters (F-v/F-m, P-n and pigment content) of 'JD 8', a relatively heat tolerant variety, declined more slowly than those of the other three varieties during the whole heat stress period.
文摘[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditions. [ Result] A respective single peak at 11：30 was observed in diurnal variation curves of net photosynthetic rate （Pn） and transpiration rate（Tr）. Correlation analysis shows that Pn presents an extremely significant correlation with photon flux densities （PFD） of photosynthetically active radiation, in comparison assumes a significant correlation either with stomatal conductance （Gs） or with ambient CO2 concentration （Ca）. [ Conclusion] Gs followed by PFD presented most influence on Pn of super high-yield combination C Liangyou H255.
文摘The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.
基金Supported by Special Project of China Meteorological Administrationon Effects of Climate Change on Solar Energy in East ChinaSpecial fund of Meteorological Science and Technology Services inShandong Province in 2006~~
文摘To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...
基金Supported by National Natural Science Foundation of China(31101124)National Modern Rapeseed Industry Technology System~~
文摘[Objective] The aim was to evaluate the effects of different concentrations of ABA on photosynthetic characteristics of pods and yield of Brassica napus and analyze the relationships between ABA concentration and yield components, to provide theoretical basis for cultivation of high-yield rapeseed. [Method] At the end of flowering stage, the rape plants were separately sprayed with 1, 2, 100 and 200μmol/L of ABA; photosynthetic parameters, water use efficiency （WUE）, yield and yield components of the rape plants were investigated 0, 5, 10 and 15 d later, respectively. [Result] ABA treatment with different concentrations significantly changed pod photosynthetic parameters and yield components of rapeseed. Low concentra- tions of ABA could improve pod＇s net photosynthetic rate and yield components while high concentrations had the contrary effect. [Conclusion] Whether ABA func- tioned in inhibiting or promoting role might depend on the interaction between endogenous hormone levels and exogenous ABA concentration. Improvement of WUE would be the main reason for yield increasing.
基金Supported by Natural Science Foundation of Hainan Province(80645)~~
文摘[Objective] The aim of this study is to understand the high yield often photosynthetic mechanism of super hybrid rice P88S/0389.[Method] Chlorophyll and carotenoid contents were measured via the method of Wellburn and Lichtenthaler,and the photosynthetic rate and chlorophyll fluorescence parameters were measured using portable photosynthesis system.Through comparison of above measured indices between P88S/0389 and its parents,the photosynthetic characteristics were obtained.[Result] The pigment content of P88S/0389 lied between their parents,and detailedly was closer to its female parent at earlier growth stage and to its male parent at latter stage,respectively.The Pn,Fv/Fo,Fv/Fm and qP of the flag leaf of P88S/0389 were all higher than those of its parents,while the degradation rates of these parameters were slower than those of its parents.The qN of flag leaf was lower than those of its parents,and the increasing rate of qN of P88S/0389 was also slower than those of its parents,indicating the great heterosis of P88S/0389 to its parents in photosynthetic capacity.The data show that P88S/0389 is endowed with stronger capacities in light energy absorption,transformation and carbon fixation compared to its parents.[Conclusion] The light energy absorbed by hybrid mainly contributes to photochemical reaction,and little for heat dissipation.For ensuring high yield,the rice cultivars selected for production should synchronously possess higher photosynthetic rate and longer high value duration.
基金Supported by the Key of Xinjiang Characteristic Fruit Efficient Safety Production Technology Integration and Demonstration of Science and Technology Plan Projects in Xinjiang Uygur Autonomous Region(201130102-1)Modern Agricultural Industry Technology System Special Funding(CARS-30)Xin Jiang Uygur Autonomous Region Fruit Trees Key Subject~~
文摘[Objective] The aim was to explore the photosynthetic characteristics of Turpan grapes under high temperature and strong light conditions. [Method] Using six grape varieties as experimental materials, the photosynthesis and fluorescence parameters of the grape varieties under high temperature and high light were determined. [Result] The results showed that Thompson Seedless showed strong selfprotection ability on the photosynthetic mechanism in the adversity, and lower photo inhibition on photosynthesis under high temperature and high light than other varieties in which Crimson Seedless was second place. Otherwise the damage on photosynthetic mechanism of Kyoho and Red Globe under the adversity environment is more dipper than the other varieties, and poor self-protection ability. [Conclusion]Thompson Seedless and Crimson Seedless had a strong adaptability for high temperature and strong light. But the adaptability of Kyoho and Red Globe were relatively poor.
