Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamp...Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.展开更多
Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain...Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.展开更多
Negative effect of precipitation on plant photosynthesis was investigated in this work. Stomatal conductance, transpiration rate and net photosynthetic rate were measured before and after each precipitation event, res...Negative effect of precipitation on plant photosynthesis was investigated in this work. Stomatal conductance, transpiration rate and net photosynthetic rate were measured before and after each precipitation event, respectively, and the corresponding precipitation was recorded as well. Moreover, plant dry matter accumulation was counted at the end of our entire experiment. The results show that precipitation fully demonstrates its negative effect on plant photosynthesis under the condition of without water shortage. Although it has not been proved, leaf shape seems to be associated with this effect. Broad-leaved species are less influenced than coniferous and lanceleaf species no matter on the length of variation time or changes in variation values. The different situation among three broad-leaved species seems to illustrate that the effect is also related to the size of single leaf area. The correlation between precipitation and photosynthetic rate variation is analogous to the relationship between precipitation and splash erosion, and in the view of the relationship between plant photosynthetic characteristics and dry mass accumulation, it can be thought that it can reflect the negative impact of precipitation on plant growth by making use of splash erosion. Therefore, a section was added in the traditional plant biomass estimation algorithms by using eco-physiological models, and this was proved to enhance the accuracy of traditional estimation from preliminary verifications.展开更多
Choline chloride can increase the activities of Hill reaction and ATPase in isolatedchloroplast from wheat leaves. It can also increase the activities of ribulose-1, 5-bisphosphate car-boxylase (RuBPCase EC 4. 1. 1. 3...Choline chloride can increase the activities of Hill reaction and ATPase in isolatedchloroplast from wheat leaves. It can also increase the activities of ribulose-1, 5-bisphosphate car-boxylase (RuBPCase EC 4. 1. 1. 39) and glyceraldehyde-3-phosphate dehydrogenase(G-3-PDHEC 1. 2. 1. 13) with the method of vacuum infiltration. But higher concentrations of choline chlo-ride tends to inhibite the activities of these enzymes. As a result of choline chloride treatment theamounts of both protein and chlorophyll can be increased, and the photosynthetic rate can beraised,too. The above data suggest that the choline chloride may act on the enzymes involved inlight reaction and dark reaction in the photosynthesis.展开更多
Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promot...Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promoting the crop growth.Using Sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics.The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.50 g·kg -1 .展开更多
Background Zinc(Zn),being the most deficient micronutrient,can largely limit plant growth and development on alkaline calcareous soil.Crop species and varieties within species differently require Zn for optimum produc...Background Zinc(Zn),being the most deficient micronutrient,can largely limit plant growth and development on alkaline calcareous soil.Crop species and varieties within species differently require Zn for optimum productivity.The current study aimed to optimize Zn level and mode of application for better growth,yield,and fiber quality of cotton(Gossypium hirsutum L.).The experimental plan comprised a control group with no Zn application,three Zn levels through soil application,i.e.5 mg·kg^(-1)(SZn5),10 mg·kg^(-1)(SZn10),and 15 mg·kg^(-1)(SZn15),two levels of foliar application including 0.5%(FZn0.5)and 1%(FZn1)Zn solution,and various combinations of soil plus foliar application.Two cotton cultivars,CIM-663(Bt)and Cyto-124(non-Bt)were used,and each treatment was replicated thrice.Results Zinc nutrition caused a significant(P≤0.05)improvement in growth,yield,physiological,and fiber quality characteristics of both cotton cultivars.All levels and modes of Zn application were found effective in improving cotton productivity on alkaline calcareous soil.However,integrated soil application and foliar spray showed superiority over sole soil or foliar application.Among different treatments,SZn15+FZn1 caused the highest improvement in most of the observed growth and yield traits.The said treatment maximally increased the leaf Zn concentration by 270.5%and 218.4%with a subsequent increase in plant height 23.2%and 28.0%,monopodial branches 40.7%and 42.1%,sympodial branches 37.2%and 35.2%,seed cotton yield 32.5%and 36.6%,and lint yield 30.0%and 34.6%in CIM-663 and Cyto-124,respectively,compared with the control.SZn15+FZn1 also caused the highest increase in relative water contents 32.6%and 22.4%,chlorophyll contents 92.0%and 67.1%,and stomatal conductance 112.8%and 100.8%in CIM-663 and Cyto-124,respectively,compared with the control.Among the fiber quality characteristics,fiber fineness was maximally improved by 19.7%and 15.9%in CIM-663 and Cyto-124,respectively,with SZn15+FZn1 compared with the control.Leaf Zn concentration was positively correlated with fiber length(R2=0.7173),fiber strength(R2=0.5483),and fiber fineness(R2=0.6379)of both cotton cultivars grown with different levels and application modes of Zn.The benefit-cost ratio was remarkably improved with Zn nutrition,and the highest value of 1.64 was found in CIM-663 at SZn10+FZn1 and SZn15+FZn1.Conclusion The plant growth,physiological,yield,and fiber quality characteristics of cotton cultivars were significantly improved with Zn supply at different levels and modes of application.SZn15+FZN1 could be recommended to get optimum seed cotton yield and fiber quality of cotton on alkaline calcareous soil.展开更多
In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic ...In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),and the base fertilizer that only applied conventional chemical fertilizer was used as the control.The total flavonoid contents and physiological indices of dandelion in different growth periods were determined.The results showed that the accumulation of the total flavonoid contents in leaves and roots of dandelion improved significantly by applying biochar-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),with the highest total flavonoid occurred in the 0.45 kg•m^(-2) biochar-based organic fertilizer treatment.Along with dandelion growing,the total flavonoid contents in leaves were first elevated,and then decreased,with the maximum reached at 95 days after sowing(anthesis).While the total flavonoid contents in roots were elevated constantly.The total flavonoid contents accumulation in dandelion were positively correlated with net photosynthetic rate,stomatal conductance,transpiration rate,soluble sugar content,soluble protein,nitrate nitrogen,and available potassium,while negatively correlated with intercellular CO_(2) concentration.展开更多
A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irri...A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation （W0）, irrigation once at jointing （W1j） or at booting （W1b）, irrigation twice at jointing and booting （W2）, and irrigation three times at jointing, booting and grain-filling （W3） and three planting densities, such as 180 （D1）, 300 （D2） and 450 （D3） seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis （resulting from more irrigation time/volume） were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.展开更多
Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlation...Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlations between PCI intensity and park characteristics such as park area,landscape shape index(LSI),green ratio and altitude were analyzed,using 3 010 temperature and humidity data from measurements in six parks with typical park characteristics in Chongqing,China.The results indicate that:1) the main factor determining PCI intensity is park area,which leads to obvious cool island effect when it exceeds 14 hm2;2) there is a negative correlation between PCI intensity and LSI,showing that the rounder the park shape is,the better the cool island effect could be achieved;3) regression analysis of humidity and PCI intensity proves that photosynthesis midday depression(PMD) is an important factor causing the low PCI intensity at 13:00;4) the multivariable linear regression model proposed here could effectively well predict the daily PCI intensity in mountain cities.展开更多
DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to st...DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.展开更多
The paper reviews the factors and mechanisms involved in the regulation of seed growth,discusses the roles of source sink relationship in yield formation and effects of climate change and canopy photosynthesis on gro...The paper reviews the factors and mechanisms involved in the regulation of seed growth,discusses the roles of source sink relationship in yield formation and effects of climate change and canopy photosynthesis on groth and yield in soybean.展开更多
Background:Cotton production in China is challenged by high labor input including manual topping(MT).Recently,to replace MT in the Xinjiang cotton region of China,mepiquat chloride(MC)was applied once more than the tr...Background:Cotton production in China is challenged by high labor input including manual topping(MT).Recently,to replace MT in the Xinjiang cotton region of China,mepiquat chloride(MC)was applied once more than the traditional multiple-application;this was designated as chemical topping(CT),but it is unclear whether the amount of irrigation needs to be adjusted to accommodate CT.Results:The main plots were assigned to three drip irrigation amounts[300(I_(1))480(I_(2)), and 660(I_(3))mm],and the subplots were assigned to the CT treatments[450(MC)750(MC_(2)),and 1050(MC_(3))mL·hm^(-2)25%MC]with MT as a control that was performed after early bloom.The optimum drip irrigation amount for CT was explored based on leaf photosynthesis,chlorophyll fluorescence,biomass accumulation,and yield.There were significant influe nces of drip irrigation,topping treatme nts and their interaction on chlorophyll fluorescence characteristics,gas exchange parameters and biomass accumulation characteristics as well as yield.The combination of I_(2) and MC_(2)(I_(2)MC_(2))performed best.Compared with I_(2)MC_(2)the net photosynthetic rate(Pn),stomatai conductance(Gs),transpiration rate(Tr),and photochemical quenching coefficient(qP)of I_(2)MC_(2)significantly increased by 4.0%~7.2%,6.8%〜17.1%,5.2%~17.6%,and 4.8%~9.6%,respectively,from the peak flowering to boll opening stages.Moreover,I_(2)MC_(2) showed fast reproductive organ biomass accumulation and the highest seed cotton yield;the latter was 6.6%~12.8%higher than that of I_(2)MT.Further analysis revealed that a 25%MC emulsion in water(MCEW)application resulted in yield improvement by increasing Pn,φPSⅡ,and qP to promote biomass accumulation and transport to reproductive organs.Conclusion:The results showed that the 480 mm drip irrigation combined with 750 mL·hm^(-2)MC increased the rate of dry matter accumulation in reproductive organs by increasing Pn,φPSⅡ and qP to improve photosynthetic performance,thus achieving higher yield.展开更多
Many photosynthetic characteristics of three plum varieties were studied with a infrared CO2 analyzer. Results showed that plums belong to light - loving species, having a relative high light compensation point (75-80...Many photosynthetic characteristics of three plum varieties were studied with a infrared CO2 analyzer. Results showed that plums belong to light - loving species, having a relative high light compensation point (75-80μmol· m-2·s-1). In natural light range from none to 1400μmol·m-2s-1PAR,the light response curve of plum as a hyperbo and the net photosynthetic rate(Pn) in leavs increased with PA elevation. Pn of plum tree was 20 to 22.50mg CO2·dm-1·h-1 at 1380μpol. m-2·s-1 PAN,indicating that plum was typi- cal C3-type fruit tree. Diurnal change in Pn was a bimoal curve with the highest photosynthetic rate arising at about 10:00 a. m. indicated the clear 'none - rest 'characteristic in plum leaves. Among three varieties. SuiLi3 had the shortest 'none - rest' time followed by JiLin6 and NuXinLi. Seasonal change in Pn was a bi- modal curve with the first period of high Pn in late June and the second in late August. Pn in leaves decreased visibly in period of drought in Spring and Summer.展开更多
While comparing photosynthetic characteristics of Dryopteris fragrans(L.) Schott to those of several commonly associated plants in its native community, coordination between D. fragrans and its environment was observe...While comparing photosynthetic characteristics of Dryopteris fragrans(L.) Schott to those of several commonly associated plants in its native community, coordination between D. fragrans and its environment was observed. The diurnal net photosynthetic rate(Pn) varied dramatically for all the plants studied. D. fragrans, Woodsia ilvensis and Urtica angustifolia all exhibited unimodal type Pn variation, with low Pn, weak photosynthetic capacity, and dramatic maximal photosynthesis(Pmax) changes. When compared to values for its associated plants, D. fragrans values were of intermediate level, indicating difficulty in adapting to its environment. Moreover, the nitrate reductase activity of D. fragrans was higher than that of only one species, Artemisia gmelinii. With increasing leaf maturity and chlorophyll content, D. fragrans exhibited declining LCP(light compensation point) and a relatively low LSP(light saturation point). Because of its overall relatively weak photosynthetic capacity, D. fragrans exhibited narrow ecological amplitude with respect to light adaptation.展开更多
This paper deals with the photosynthetic properties of Eucalyptue camphoia. E. camaldulenaia. E. gunni-i. E. viminalia. E. giandia. E. dunii and E. maidenii. including the daily bariations of photosynthetic and respir...This paper deals with the photosynthetic properties of Eucalyptue camphoia. E. camaldulenaia. E. gunni-i. E. viminalia. E. giandia. E. dunii and E. maidenii. including the daily bariations of photosynthetic and respiratory rates, the comparison of the photosynthetic rates of various Eucalyriua spp. measured,the relationship between photo-synthetic rate and chlorophyll content, as well as the light saturation point.展开更多
基金funded by the China Agriculture Research System(CARS-15-16).
文摘Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.
基金supported by the National Natural Science Foundation of China(grant no.31960385)the Natural Science Foundation of Jiangxi,China(grant no.20212BAB215009)。
文摘Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.
基金Project(TD2011-01)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(20133050)supported by the China Scholarship Council
文摘Negative effect of precipitation on plant photosynthesis was investigated in this work. Stomatal conductance, transpiration rate and net photosynthetic rate were measured before and after each precipitation event, respectively, and the corresponding precipitation was recorded as well. Moreover, plant dry matter accumulation was counted at the end of our entire experiment. The results show that precipitation fully demonstrates its negative effect on plant photosynthesis under the condition of without water shortage. Although it has not been proved, leaf shape seems to be associated with this effect. Broad-leaved species are less influenced than coniferous and lanceleaf species no matter on the length of variation time or changes in variation values. The different situation among three broad-leaved species seems to illustrate that the effect is also related to the size of single leaf area. The correlation between precipitation and photosynthetic rate variation is analogous to the relationship between precipitation and splash erosion, and in the view of the relationship between plant photosynthetic characteristics and dry mass accumulation, it can be thought that it can reflect the negative impact of precipitation on plant growth by making use of splash erosion. Therefore, a section was added in the traditional plant biomass estimation algorithms by using eco-physiological models, and this was proved to enhance the accuracy of traditional estimation from preliminary verifications.
文摘Choline chloride can increase the activities of Hill reaction and ATPase in isolatedchloroplast from wheat leaves. It can also increase the activities of ribulose-1, 5-bisphosphate car-boxylase (RuBPCase EC 4. 1. 1. 39) and glyceraldehyde-3-phosphate dehydrogenase(G-3-PDHEC 1. 2. 1. 13) with the method of vacuum infiltration. But higher concentrations of choline chlo-ride tends to inhibite the activities of these enzymes. As a result of choline chloride treatment theamounts of both protein and chlorophyll can be increased, and the photosynthetic rate can beraised,too. The above data suggest that the choline chloride may act on the enzymes involved inlight reaction and dark reaction in the photosynthesis.
文摘Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promoting the crop growth.Using Sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics.The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.50 g·kg -1 .
文摘Background Zinc(Zn),being the most deficient micronutrient,can largely limit plant growth and development on alkaline calcareous soil.Crop species and varieties within species differently require Zn for optimum productivity.The current study aimed to optimize Zn level and mode of application for better growth,yield,and fiber quality of cotton(Gossypium hirsutum L.).The experimental plan comprised a control group with no Zn application,three Zn levels through soil application,i.e.5 mg·kg^(-1)(SZn5),10 mg·kg^(-1)(SZn10),and 15 mg·kg^(-1)(SZn15),two levels of foliar application including 0.5%(FZn0.5)and 1%(FZn1)Zn solution,and various combinations of soil plus foliar application.Two cotton cultivars,CIM-663(Bt)and Cyto-124(non-Bt)were used,and each treatment was replicated thrice.Results Zinc nutrition caused a significant(P≤0.05)improvement in growth,yield,physiological,and fiber quality characteristics of both cotton cultivars.All levels and modes of Zn application were found effective in improving cotton productivity on alkaline calcareous soil.However,integrated soil application and foliar spray showed superiority over sole soil or foliar application.Among different treatments,SZn15+FZn1 caused the highest improvement in most of the observed growth and yield traits.The said treatment maximally increased the leaf Zn concentration by 270.5%and 218.4%with a subsequent increase in plant height 23.2%and 28.0%,monopodial branches 40.7%and 42.1%,sympodial branches 37.2%and 35.2%,seed cotton yield 32.5%and 36.6%,and lint yield 30.0%and 34.6%in CIM-663 and Cyto-124,respectively,compared with the control.SZn15+FZn1 also caused the highest increase in relative water contents 32.6%and 22.4%,chlorophyll contents 92.0%and 67.1%,and stomatal conductance 112.8%and 100.8%in CIM-663 and Cyto-124,respectively,compared with the control.Among the fiber quality characteristics,fiber fineness was maximally improved by 19.7%and 15.9%in CIM-663 and Cyto-124,respectively,with SZn15+FZn1 compared with the control.Leaf Zn concentration was positively correlated with fiber length(R2=0.7173),fiber strength(R2=0.5483),and fiber fineness(R2=0.6379)of both cotton cultivars grown with different levels and application modes of Zn.The benefit-cost ratio was remarkably improved with Zn nutrition,and the highest value of 1.64 was found in CIM-663 at SZn10+FZn1 and SZn15+FZn1.Conclusion The plant growth,physiological,yield,and fiber quality characteristics of cotton cultivars were significantly improved with Zn supply at different levels and modes of application.SZn15+FZN1 could be recommended to get optimum seed cotton yield and fiber quality of cotton on alkaline calcareous soil.
基金Supported by the National Key Research and Development Project(2021YFD16009012021YFD1600902)。
文摘In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),and the base fertilizer that only applied conventional chemical fertilizer was used as the control.The total flavonoid contents and physiological indices of dandelion in different growth periods were determined.The results showed that the accumulation of the total flavonoid contents in leaves and roots of dandelion improved significantly by applying biochar-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),with the highest total flavonoid occurred in the 0.45 kg•m^(-2) biochar-based organic fertilizer treatment.Along with dandelion growing,the total flavonoid contents in leaves were first elevated,and then decreased,with the maximum reached at 95 days after sowing(anthesis).While the total flavonoid contents in roots were elevated constantly.The total flavonoid contents accumulation in dandelion were positively correlated with net photosynthetic rate,stomatal conductance,transpiration rate,soluble sugar content,soluble protein,nitrate nitrogen,and available potassium,while negatively correlated with intercellular CO_(2) concentration.
基金Supported by China and CAS Main Direction Program of Knowledge Innovation (KSCX2-EW-B-1)China and CAS Knowledge Innovation Project(KSCX1-YW-09-06)
文摘A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation （W0）, irrigation once at jointing （W1j） or at booting （W1b）, irrigation twice at jointing and booting （W2）, and irrigation three times at jointing, booting and grain-filling （W3） and three planting densities, such as 180 （D1）, 300 （D2） and 450 （D3） seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis （resulting from more irrigation time/volume） were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.
基金Project(2006BAJ02A02-05) supported by the National Key Technologies R&D Program of China
文摘Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlations between PCI intensity and park characteristics such as park area,landscape shape index(LSI),green ratio and altitude were analyzed,using 3 010 temperature and humidity data from measurements in six parks with typical park characteristics in Chongqing,China.The results indicate that:1) the main factor determining PCI intensity is park area,which leads to obvious cool island effect when it exceeds 14 hm2;2) there is a negative correlation between PCI intensity and LSI,showing that the rounder the park shape is,the better the cool island effect could be achieved;3) regression analysis of humidity and PCI intensity proves that photosynthesis midday depression(PMD) is an important factor causing the low PCI intensity at 13:00;4) the multivariable linear regression model proposed here could effectively well predict the daily PCI intensity in mountain cities.
基金Supported by the National Natural Science Foundation of China(31201164)the Program of Science and Technology of Education Department of Heilongjiang Province(12521036)+2 种基金China Postdoctoral Science Foundation(2012M511434)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z12036)the Doctoral Starting Up Foundation of Northeast Agricultural University(2012RCB01)
文摘DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.
文摘The paper reviews the factors and mechanisms involved in the regulation of seed growth,discusses the roles of source sink relationship in yield formation and effects of climate change and canopy photosynthesis on groth and yield in soybean.
基金financially supported by the Research Fund for the National Natural Science Foundation of China (31760369)Xinjiang Corps Science and Technology Innovation Talent Program (2020CB014)Major projects of the eighth Division (2020ZD01)
文摘Background:Cotton production in China is challenged by high labor input including manual topping(MT).Recently,to replace MT in the Xinjiang cotton region of China,mepiquat chloride(MC)was applied once more than the traditional multiple-application;this was designated as chemical topping(CT),but it is unclear whether the amount of irrigation needs to be adjusted to accommodate CT.Results:The main plots were assigned to three drip irrigation amounts[300(I_(1))480(I_(2)), and 660(I_(3))mm],and the subplots were assigned to the CT treatments[450(MC)750(MC_(2)),and 1050(MC_(3))mL·hm^(-2)25%MC]with MT as a control that was performed after early bloom.The optimum drip irrigation amount for CT was explored based on leaf photosynthesis,chlorophyll fluorescence,biomass accumulation,and yield.There were significant influe nces of drip irrigation,topping treatme nts and their interaction on chlorophyll fluorescence characteristics,gas exchange parameters and biomass accumulation characteristics as well as yield.The combination of I_(2) and MC_(2)(I_(2)MC_(2))performed best.Compared with I_(2)MC_(2)the net photosynthetic rate(Pn),stomatai conductance(Gs),transpiration rate(Tr),and photochemical quenching coefficient(qP)of I_(2)MC_(2)significantly increased by 4.0%~7.2%,6.8%〜17.1%,5.2%~17.6%,and 4.8%~9.6%,respectively,from the peak flowering to boll opening stages.Moreover,I_(2)MC_(2) showed fast reproductive organ biomass accumulation and the highest seed cotton yield;the latter was 6.6%~12.8%higher than that of I_(2)MT.Further analysis revealed that a 25%MC emulsion in water(MCEW)application resulted in yield improvement by increasing Pn,φPSⅡ,and qP to promote biomass accumulation and transport to reproductive organs.Conclusion:The results showed that the 480 mm drip irrigation combined with 750 mL·hm^(-2)MC increased the rate of dry matter accumulation in reproductive organs by increasing Pn,φPSⅡ and qP to improve photosynthetic performance,thus achieving higher yield.
文摘Many photosynthetic characteristics of three plum varieties were studied with a infrared CO2 analyzer. Results showed that plums belong to light - loving species, having a relative high light compensation point (75-80μmol· m-2·s-1). In natural light range from none to 1400μmol·m-2s-1PAR,the light response curve of plum as a hyperbo and the net photosynthetic rate(Pn) in leavs increased with PA elevation. Pn of plum tree was 20 to 22.50mg CO2·dm-1·h-1 at 1380μpol. m-2·s-1 PAN,indicating that plum was typi- cal C3-type fruit tree. Diurnal change in Pn was a bimoal curve with the highest photosynthetic rate arising at about 10:00 a. m. indicated the clear 'none - rest 'characteristic in plum leaves. Among three varieties. SuiLi3 had the shortest 'none - rest' time followed by JiLin6 and NuXinLi. Seasonal change in Pn was a bi- modal curve with the first period of high Pn in late June and the second in late August. Pn in leaves decreased visibly in period of drought in Spring and Summer.
基金Supported by Funding(Topic 31072091/C020601)from the NSFC(Natural Science Foundation of China)(20082010)
文摘While comparing photosynthetic characteristics of Dryopteris fragrans(L.) Schott to those of several commonly associated plants in its native community, coordination between D. fragrans and its environment was observed. The diurnal net photosynthetic rate(Pn) varied dramatically for all the plants studied. D. fragrans, Woodsia ilvensis and Urtica angustifolia all exhibited unimodal type Pn variation, with low Pn, weak photosynthetic capacity, and dramatic maximal photosynthesis(Pmax) changes. When compared to values for its associated plants, D. fragrans values were of intermediate level, indicating difficulty in adapting to its environment. Moreover, the nitrate reductase activity of D. fragrans was higher than that of only one species, Artemisia gmelinii. With increasing leaf maturity and chlorophyll content, D. fragrans exhibited declining LCP(light compensation point) and a relatively low LSP(light saturation point). Because of its overall relatively weak photosynthetic capacity, D. fragrans exhibited narrow ecological amplitude with respect to light adaptation.
基金Subsist by the National Natural Science foundation of China
文摘This paper deals with the photosynthetic properties of Eucalyptue camphoia. E. camaldulenaia. E. gunni-i. E. viminalia. E. giandia. E. dunii and E. maidenii. including the daily bariations of photosynthetic and respiratory rates, the comparison of the photosynthetic rates of various Eucalyriua spp. measured,the relationship between photo-synthetic rate and chlorophyll content, as well as the light saturation point.
