To monitor growth and predict the yield of rice over a large area, the chlorophyll contents in the rice canopy were estimated using the unmanned aerial vehicle(UAV) remote sensing technology. In this work, multi-spect...To monitor growth and predict the yield of rice over a large area, the chlorophyll contents in the rice canopy were estimated using the unmanned aerial vehicle(UAV) remote sensing technology. In this work, multi-spectral image information of the rice crop was obtained using a 6-channel multi-spectral camera mounted on a fixed wing UAV, which was flown 600 m above the ground, between 11: 00-14: 00 on a sunny day in summer. The measured chlorophyll values were collected as sample sets. The s-REP index was screened out to estimate chlorophyll contents through the analysis of six kinds of spectral indexes of chlorophyll estimated capacity. An inversion model of the chlorophyll contents was then built using the least square support vector regression(LS-SVR)algorithm, with calibration and prediction R-square values of 0.89 and 0.83, respectively. Finally, remote sensing mapping for a UAV image of the Fangzheng County Dexter Rice Planting Park was accomplished using the inversion model. The inversion and measured values were then compared using regression fitting. R-square and root-mean-square error of the fitting model were 0.79 and 2.39,respectively. The results demonstrated that accurate estimation of rice-canopy chlorophyll contents was feasible using the LS-SVR inversion model developed using the s-REP vegetation index.展开更多
In this paper,three soybean varieties with different qualities were used as experimental materials for potted plants.In the seedling stage and the flowering stage,different concentrations of lanthanum and cerium(120,1...In this paper,three soybean varieties with different qualities were used as experimental materials for potted plants.In the seedling stage and the flowering stage,different concentrations of lanthanum and cerium(120,150 and 180 mg·L^-1 LaCl3;30,60 and90 mg·L^-1 CeCl3;30,40 and 60 mg·L^-1 LaCl3+30,40 and 60 mg·L^-1 CeCl3)were sprayed to study the effects of lanthanum and cerium on soybeans(leaf photosynthetic pigment content,yield and the constituent factors).The results showed that chlorophyll contents of different qualities soybean leaves reached the maximum under 120 mg·L^-1 LaCl3 treatment.The yield of high protein soybean was the highest under 60 mg·L^-1 CeCl3 treatment,the yield of high fat soybean was the highest under 30 mg·L^-1 CeCl3 treatment.Therefore,the lanthanum and cerium solutions had the effect of"low promotion and high inhibition"on chlorophyll content of soybeans,and the cerium solution could increase the yields of different quality soybeans.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
A total of nine soybean （Glycine max （L.） Merr.） cultivars were divided into three yield levels which were planted under the same environmental condition. The net photosynthetic rate was measured by LI-6400 portab...A total of nine soybean （Glycine max （L.） Merr.） cultivars were divided into three yield levels which were planted under the same environmental condition. The net photosynthetic rate was measured by LI-6400 portable photosynthesis system. The chlorophyll content and specific leaf weight were measured with regular methods. The results showed that the specific leaf weight, chlorophyll content and net photosynthetic rate of high yield varieties were higher than those of low yield varieties. The yield had a significantly positive correlation with the net photosynthetic rate. With the improvement of modem technology, the net photosynthetic rate could be measured quickly and exactly. Hence, net photosynthetic rate could be used as an effective index in the selection of high yield soybean.展开更多
At the beginning of silking, maize production began to form, but leaves started senescence and photosynthetic capacity decreased at this time, all of those severely restricted the formation of the production. In order...At the beginning of silking, maize production began to form, but leaves started senescence and photosynthetic capacity decreased at this time, all of those severely restricted the formation of the production. In order to study the effects of exogenous substances on the process of leaf senescence, 40 mg. L-1 DCPTA and 20 mg. L-1 CCC were mixed in the research. When the maize grew to the six expanded leaves stage, 10 mL compound mixtures （TR） were sprayed on both sides of leaves for per plant, and the control was treated with water （CK）. Three plants were selected randomly for determination of physiological index at 10, 20, 30, 40 and 50 days after silking. The results showed that TR could increase the chlorophyll content significantly, FvFm, Fv/F0 and Y（Ⅱ） values of TR were higher than those of CK while F0 values were opposite. Compared with CK, TR increased SOD and POD activities and soluble protein content, and reduced MDA content. Correlation analysis showed that chlorophyll content had negative correlation with F0, and MDA content had negative correlation with other indexes. Compared with CK, TR reduced the negative correlation effect between chlorophyll content and MDA, increased the positive correlation effect between chlorophyll content and Fv/Fm, SOD, PODI and soluble protein. The study provided theoretical and experimental evidence for the application of the compound mixtures of DCPTA and CCC to the production.展开更多
Reasons for the color change of E.pulcherrima were studied with physiological and biochemical paraments such as: chlorophyll,carotenoids,anthocyanin,Phenylalanine ammonia-lyase (PAL),pH of cell sap in leaves and solub...Reasons for the color change of E.pulcherrima were studied with physiological and biochemical paraments such as: chlorophyll,carotenoids,anthocyanin,Phenylalanine ammonia-lyase (PAL),pH of cell sap in leaves and soluble sugar content etc.The results showed that during the period of the leaf color transmittion of E.pulcherrima,the contents of plastid pigment,soluble sugar and pH of cells sap in leaves showed a high-low-high dynamic change,while the contents of anthocyanin and PAL activity showed the low-high...展开更多
Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） rep...Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） representing different types （＇Baron＇, BVMG type; ＇Blackstone＇, Cheri type; ＇Kenblue＇, Midwest type; and ＇Bluemoon＇, Midnight type） were chosen for this study. Grass materials were established in a glasshouse, and the changes in their photosynthetic and metabolic characteristics were analyzed during a period of imposed drought stress. Drought stress led to decrease in chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate in all four cultivars, but the relative changes in each characteristic varied among varieties. The results also showed that changes in the photosynthetic and metabolic characteristics of different varieties under drought stress were related to the morphological characteristics of the plants. Varieties with longer narrow leaves, longer roots, higher root-to-shoot ratios, and higher chlorophyll contents showed greater rates of photosynthesis and stomatal conductance, and lower transpiration rates.展开更多
common maize synthetic rate（ Photosynthetic characteristics were probed by sweet maize, waxy maize, high starch maize and The results revealed that leaf area index （LAI）, chlorophyll a content, chlorophyll b cont...common maize synthetic rate（ Photosynthetic characteristics were probed by sweet maize, waxy maize, high starch maize and The results revealed that leaf area index （LAI）, chlorophyll a content, chlorophyll b content,photo-PR） showed single peak curve at the whole growth stage. The stages of peak were different according to different varieties. NEAUS4 had the lowest peak and while SIDAN 19 had the highest among all stages. Ratio of chlorophyll a to b was low at seedling stage, reached the peak atjointing stage and then declined. SIDAN 19 had the lower level at the last stages.展开更多
Heavy metal pollution of soil is one of serious problems of environment.Not easy to break down, heavy metal was enriched and became the pollutants. It would not only destroy the normal function of soil and impede the ...Heavy metal pollution of soil is one of serious problems of environment.Not easy to break down, heavy metal was enriched and became the pollutants. It would not only destroy the normal function of soil and impede the growth of crops,but also through the food chain cause the harm to human health.By the impact of heavy metal pollution of soil,the vegetation is also very easy to be contaminated.When the vegetation has been contaminated,its internal structure,展开更多
A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intra...A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intraspecies polymorphism ofresponse to the different level of mineralnutrition was identified.An individual展开更多
As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eighta...As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eightamino acid residues from the antimicrobialpeptide ceropin A with a modified meltin.Threetransgenic cotton plants were generated展开更多
Background:The photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period.This study was undertaken during 2015-2017 in Xinjiang,China,to determine to what ext...Background:The photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period.This study was undertaken during 2015-2017 in Xinjiang,China,to determine to what extent the film mulching removal time,1 and 10 days before the first irrigation and 1 day before the second irrigation after seedling emergence,influenced cotton's photosynthetic characteristics.The control group(CK)was film-mulched throughout the growth stages.Results:The results suggested the following:(1)Removing mulching-film within 50 days since seedling emergence had adverse effects on soil temperature and moisture.(2)Film-removal before the first or second irrigation after emergence improved the net photosynthetic rate in cotton's later flowering stage and its transpiration rate in mid and later flowed ng stages while enhancing the actual electron transport rate(ETR)and maximum electron transfer rate(ETRmax)between cotton photosystems I and II.(3)Film-removal treatment also increased cotton plants'toleranee to high irradiation after emergence,the trend was more pronounced in the early flowering stage in wetter years.(4)Leaf area index(LAI)of cotton was reduced in the film-removal treatment for which the least accumulation of dry matter occurred in a drought year(i.e.,2015).(5)Film removal caused a yield decrease in the dry year(2015),and the earlier the film was removed,the more seriously the yield decreased.Removing mulching film before the second irrigation could increase the yield of XLZ42 in the rainy year(2016)and the normal rainfall year(2017).Early film removal can in crease the yield of XLZ45 in the rainy year(2016).Conclusions:Collectively,our stud/s experimental results indicate that applying mulch film removal at an appropriate,targeted time after seedling emerge nee had no adverse effects on soil moisture and temperature,and improved the photosy nthetic performance of cotton,thus in creased cotton yield and fiber quality,but no significant difference was reached.展开更多
Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in...Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in current cotton varieties. The genotypes that can tolerate flooding are not reported earlier. The studies were conducted to explore hypoxia tolerance in local germplasm which will help to develop hypoxia tolerant cotton varieties. Method： An experiment with randomized complete different cotton varieties. The genotypes were given conditions. blocks was designed to study the hypoxia tolerance in two treatments i.e., water logged and non-water logged Results： The genotypes showed significant variability for yield, fiber and physiological traits. The hypoxia studies revealed that there is significant reduction for plant height in water sensitive genotype LRA-5166. The genotype MNH-786 showed better yield and MNH-556 showed superior ginning outturn percentage under water logged conditions. Staple length, strength and micronaire values also decreased under hypoxia. Similar pattern of negative effects were observed for Chlorophyll a, b contents and chl a/b ratio. Two hypoxia tolerant cultivars CIM-573 and MNH-564 had significantly higher chlorophyll a （1.664, 1.551） than other cultivars under both normal and waterlogged conditions. There was a significant decrease in total free amino acids in all genotypes/cultivars due to waterlogging. Free amino acid contents were significantly higher in two waterlogging sensitive cultivars, CEDIX and N-KRISHMA, than other cultivars under both non-waterlogged and waterlogged conditions. Waterlogging caused a significant reduction in shoot soluble proteins and increase in shoot proline. The genotype LRA-5166 was the highest in shoot soluble proteins content and showed significant decrease in shoot proline. Conclusions： With respect to yield MNH-786 showed better results and regarding ginning outturn percentage MNH-556 exhibited superior performance. The genotypes CIM-573 and MNH-564 showed higher chlorophyll a values. The above said genotypes may be exploited for further studies related to hypoxia tolerance.展开更多
In order to investigate the visible-NIR spectral features of the leaves of a sugarcane variety(ROC 22),the spectral reflectance and the chlorophyll content were measured in the laboratory,and their correlations were a...In order to investigate the visible-NIR spectral features of the leaves of a sugarcane variety(ROC 22),the spectral reflectance and the chlorophyll content were measured in the laboratory,and their correlations were analyzed.Prediction models were built eventually.Results showed that the negative correlations with r greater than 0.8 was found in 527-578 nm and 701-731nm between spectral reflectance and chlorophyll content.And the red edge position(REP)was also found having high correlation with chlorophyll content,with the highest r of 0.8442.In order to explore the most sensitive bands for normalized difference vegetation index(NDVI),48471 NDVI values were computed with different wavebands for each sample and their correlations with chlorophyll were also analyzed.The distribution maps of NDVI and its correlations in a two-spectral-dimension space both indicated that the red bands had significant influence than the NIR bands.The suggested sensitive red range was 710-735 nm,especially720-725 nm;and the sensitive NIR range was from 780-850 nm,which had the higher robustness.The chlorophyll predication model with NDVI(725 and 840 nm)in tillering stage had determination coefficients of 0.7386,and was recommended for guiding the subsequent ridging fertilization.展开更多
Recent advances in optical remote sensing led to improved methodologies to monitor crop properties.The red-edge-based vegetation index considered to be one of the most powerful tools for estimating the chlorophyll con...Recent advances in optical remote sensing led to improved methodologies to monitor crop properties.The red-edge-based vegetation index considered to be one of the most powerful tools for estimating the chlorophyll content(Chl)was usually constructed from in-situ hyperspectral reflectance.In this paper,we present the work done to compare the Chl predictive quality by various red-edge-based vegetation indices based on the CASI data.The results indicated that among the selected vegetation indices,TCARI/OSAVI-based model estimated Chl(R2=0.46,RMSE=0.60 and P<0.01)with the best accuracy.To search the optimal vegetation index for Chl estimation,the normalized difference spectral index(NDSI)and ratio spectral index(RSI)were developed by using the waveband combination algorithm.A high linear correlation(R2=0.79,RMSE=0.38 and P<0.01)was acquired by combining the 869.20 and 754.90 nm wavebands,then NDSI(869.20,754.90)was applied to the CASI image to generate the Chl distribution map.It suggests that more fertilizer should be provided for the southwest areas due to the lower Chl.展开更多
基金Supported by the National Key R&D Program of China(2016YFD0300610)
文摘To monitor growth and predict the yield of rice over a large area, the chlorophyll contents in the rice canopy were estimated using the unmanned aerial vehicle(UAV) remote sensing technology. In this work, multi-spectral image information of the rice crop was obtained using a 6-channel multi-spectral camera mounted on a fixed wing UAV, which was flown 600 m above the ground, between 11: 00-14: 00 on a sunny day in summer. The measured chlorophyll values were collected as sample sets. The s-REP index was screened out to estimate chlorophyll contents through the analysis of six kinds of spectral indexes of chlorophyll estimated capacity. An inversion model of the chlorophyll contents was then built using the least square support vector regression(LS-SVR)algorithm, with calibration and prediction R-square values of 0.89 and 0.83, respectively. Finally, remote sensing mapping for a UAV image of the Fangzheng County Dexter Rice Planting Park was accomplished using the inversion model. The inversion and measured values were then compared using regression fitting. R-square and root-mean-square error of the fitting model were 0.79 and 2.39,respectively. The results demonstrated that accurate estimation of rice-canopy chlorophyll contents was feasible using the LS-SVR inversion model developed using the s-REP vegetation index.
基金Supported by the National Natural Science Foundation of China(31471440)。
文摘In this paper,three soybean varieties with different qualities were used as experimental materials for potted plants.In the seedling stage and the flowering stage,different concentrations of lanthanum and cerium(120,150 and 180 mg·L^-1 LaCl3;30,60 and90 mg·L^-1 CeCl3;30,40 and 60 mg·L^-1 LaCl3+30,40 and 60 mg·L^-1 CeCl3)were sprayed to study the effects of lanthanum and cerium on soybeans(leaf photosynthetic pigment content,yield and the constituent factors).The results showed that chlorophyll contents of different qualities soybean leaves reached the maximum under 120 mg·L^-1 LaCl3 treatment.The yield of high protein soybean was the highest under 60 mg·L^-1 CeCl3 treatment,the yield of high fat soybean was the highest under 30 mg·L^-1 CeCl3 treatment.Therefore,the lanthanum and cerium solutions had the effect of"low promotion and high inhibition"on chlorophyll content of soybeans,and the cerium solution could increase the yields of different quality soybeans.
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 Natural Science Foundation of China (30871547)Foundation of Department of Education of Jilin Province (2006041)Scientific Research Foundation of Jilin Agricultural University (2009028)
文摘A total of nine soybean （Glycine max （L.） Merr.） cultivars were divided into three yield levels which were planted under the same environmental condition. The net photosynthetic rate was measured by LI-6400 portable photosynthesis system. The chlorophyll content and specific leaf weight were measured with regular methods. The results showed that the specific leaf weight, chlorophyll content and net photosynthetic rate of high yield varieties were higher than those of low yield varieties. The yield had a significantly positive correlation with the net photosynthetic rate. With the improvement of modem technology, the net photosynthetic rate could be measured quickly and exactly. Hence, net photosynthetic rate could be used as an effective index in the selection of high yield soybean.
基金Supported by the National Natural Science Foundation of Youth Science Foundation(31201164)Northeast Agricultural University Doctor Started Foundation(2012RCB01)+1 种基金China Postdoctoral Foundation(2012M511434)Project of National Non-profi t Institute Fund(BSRF201405)
文摘At the beginning of silking, maize production began to form, but leaves started senescence and photosynthetic capacity decreased at this time, all of those severely restricted the formation of the production. In order to study the effects of exogenous substances on the process of leaf senescence, 40 mg. L-1 DCPTA and 20 mg. L-1 CCC were mixed in the research. When the maize grew to the six expanded leaves stage, 10 mL compound mixtures （TR） were sprayed on both sides of leaves for per plant, and the control was treated with water （CK）. Three plants were selected randomly for determination of physiological index at 10, 20, 30, 40 and 50 days after silking. The results showed that TR could increase the chlorophyll content significantly, FvFm, Fv/F0 and Y（Ⅱ） values of TR were higher than those of CK while F0 values were opposite. Compared with CK, TR increased SOD and POD activities and soluble protein content, and reduced MDA content. Correlation analysis showed that chlorophyll content had negative correlation with F0, and MDA content had negative correlation with other indexes. Compared with CK, TR reduced the negative correlation effect between chlorophyll content and MDA, increased the positive correlation effect between chlorophyll content and Fv/Fm, SOD, PODI and soluble protein. The study provided theoretical and experimental evidence for the application of the compound mixtures of DCPTA and CCC to the production.
文摘Reasons for the color change of E.pulcherrima were studied with physiological and biochemical paraments such as: chlorophyll,carotenoids,anthocyanin,Phenylalanine ammonia-lyase (PAL),pH of cell sap in leaves and soluble sugar content etc.The results showed that during the period of the leaf color transmittion of E.pulcherrima,the contents of plastid pigment,soluble sugar and pH of cells sap in leaves showed a high-low-high dynamic change,while the contents of anthocyanin and PAL activity showed the low-high...
基金Supported by the National Natural Science Foundation of China (30871735 31272191)+1 种基金the Natural Science Foundation of Heilongjiang Province(C0207 C200619)
文摘Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） representing different types （＇Baron＇, BVMG type; ＇Blackstone＇, Cheri type; ＇Kenblue＇, Midwest type; and ＇Bluemoon＇, Midnight type） were chosen for this study. Grass materials were established in a glasshouse, and the changes in their photosynthetic and metabolic characteristics were analyzed during a period of imposed drought stress. Drought stress led to decrease in chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate in all four cultivars, but the relative changes in each characteristic varied among varieties. The results also showed that changes in the photosynthetic and metabolic characteristics of different varieties under drought stress were related to the morphological characteristics of the plants. Varieties with longer narrow leaves, longer roots, higher root-to-shoot ratios, and higher chlorophyll contents showed greater rates of photosynthesis and stomatal conductance, and lower transpiration rates.
文摘common maize synthetic rate（ Photosynthetic characteristics were probed by sweet maize, waxy maize, high starch maize and The results revealed that leaf area index （LAI）, chlorophyll a content, chlorophyll b content,photo-PR） showed single peak curve at the whole growth stage. The stages of peak were different according to different varieties. NEAUS4 had the lowest peak and while SIDAN 19 had the highest among all stages. Ratio of chlorophyll a to b was low at seedling stage, reached the peak atjointing stage and then declined. SIDAN 19 had the lower level at the last stages.
文摘Heavy metal pollution of soil is one of serious problems of environment.Not easy to break down, heavy metal was enriched and became the pollutants. It would not only destroy the normal function of soil and impede the growth of crops,but also through the food chain cause the harm to human health.By the impact of heavy metal pollution of soil,the vegetation is also very easy to be contaminated.When the vegetation has been contaminated,its internal structure,
文摘A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intraspecies polymorphism ofresponse to the different level of mineralnutrition was identified.An individual
文摘As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eightamino acid residues from the antimicrobialpeptide ceropin A with a modified meltin.Threetransgenic cotton plants were generated
基金the special fund for scientific research into non-profit industries(agriculture,grant no.201503120).
文摘Background:The photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period.This study was undertaken during 2015-2017 in Xinjiang,China,to determine to what extent the film mulching removal time,1 and 10 days before the first irrigation and 1 day before the second irrigation after seedling emergence,influenced cotton's photosynthetic characteristics.The control group(CK)was film-mulched throughout the growth stages.Results:The results suggested the following:(1)Removing mulching-film within 50 days since seedling emergence had adverse effects on soil temperature and moisture.(2)Film-removal before the first or second irrigation after emergence improved the net photosynthetic rate in cotton's later flowering stage and its transpiration rate in mid and later flowed ng stages while enhancing the actual electron transport rate(ETR)and maximum electron transfer rate(ETRmax)between cotton photosystems I and II.(3)Film-removal treatment also increased cotton plants'toleranee to high irradiation after emergence,the trend was more pronounced in the early flowering stage in wetter years.(4)Leaf area index(LAI)of cotton was reduced in the film-removal treatment for which the least accumulation of dry matter occurred in a drought year(i.e.,2015).(5)Film removal caused a yield decrease in the dry year(2015),and the earlier the film was removed,the more seriously the yield decreased.Removing mulching film before the second irrigation could increase the yield of XLZ42 in the rainy year(2016)and the normal rainfall year(2017).Early film removal can in crease the yield of XLZ45 in the rainy year(2016).Conclusions:Collectively,our stud/s experimental results indicate that applying mulch film removal at an appropriate,targeted time after seedling emerge nee had no adverse effects on soil moisture and temperature,and improved the photosy nthetic performance of cotton,thus in creased cotton yield and fiber quality,but no significant difference was reached.
文摘Background： Hypoxia tolerance studies in cotton are very rare in Pakistan. Unpredicted and excessive rainfalls result in severe losses to cotton crop in many regions of the country due to lack of hypoxia tolerance in current cotton varieties. The genotypes that can tolerate flooding are not reported earlier. The studies were conducted to explore hypoxia tolerance in local germplasm which will help to develop hypoxia tolerant cotton varieties. Method： An experiment with randomized complete different cotton varieties. The genotypes were given conditions. blocks was designed to study the hypoxia tolerance in two treatments i.e., water logged and non-water logged Results： The genotypes showed significant variability for yield, fiber and physiological traits. The hypoxia studies revealed that there is significant reduction for plant height in water sensitive genotype LRA-5166. The genotype MNH-786 showed better yield and MNH-556 showed superior ginning outturn percentage under water logged conditions. Staple length, strength and micronaire values also decreased under hypoxia. Similar pattern of negative effects were observed for Chlorophyll a, b contents and chl a/b ratio. Two hypoxia tolerant cultivars CIM-573 and MNH-564 had significantly higher chlorophyll a （1.664, 1.551） than other cultivars under both normal and waterlogged conditions. There was a significant decrease in total free amino acids in all genotypes/cultivars due to waterlogging. Free amino acid contents were significantly higher in two waterlogging sensitive cultivars, CEDIX and N-KRISHMA, than other cultivars under both non-waterlogged and waterlogged conditions. Waterlogging caused a significant reduction in shoot soluble proteins and increase in shoot proline. The genotype LRA-5166 was the highest in shoot soluble proteins content and showed significant decrease in shoot proline. Conclusions： With respect to yield MNH-786 showed better results and regarding ginning outturn percentage MNH-556 exhibited superior performance. The genotypes CIM-573 and MNH-564 showed higher chlorophyll a values. The above said genotypes may be exploited for further studies related to hypoxia tolerance.
基金National Natural Science Foundation of China(31401290)Guangxi Natural Science Foundation(2015GXNSFBA139261)Guangxi Experiment Center of Science&Technology(YXKT2014003)
文摘In order to investigate the visible-NIR spectral features of the leaves of a sugarcane variety(ROC 22),the spectral reflectance and the chlorophyll content were measured in the laboratory,and their correlations were analyzed.Prediction models were built eventually.Results showed that the negative correlations with r greater than 0.8 was found in 527-578 nm and 701-731nm between spectral reflectance and chlorophyll content.And the red edge position(REP)was also found having high correlation with chlorophyll content,with the highest r of 0.8442.In order to explore the most sensitive bands for normalized difference vegetation index(NDVI),48471 NDVI values were computed with different wavebands for each sample and their correlations with chlorophyll were also analyzed.The distribution maps of NDVI and its correlations in a two-spectral-dimension space both indicated that the red bands had significant influence than the NIR bands.The suggested sensitive red range was 710-735 nm,especially720-725 nm;and the sensitive NIR range was from 780-850 nm,which had the higher robustness.The chlorophyll predication model with NDVI(725 and 840 nm)in tillering stage had determination coefficients of 0.7386,and was recommended for guiding the subsequent ridging fertilization.
基金National Natural Science Foundation of China(41401419)Foundation for the Scientific Study of Chongqing University of Art and Science(R2014LX06)
文摘Recent advances in optical remote sensing led to improved methodologies to monitor crop properties.The red-edge-based vegetation index considered to be one of the most powerful tools for estimating the chlorophyll content(Chl)was usually constructed from in-situ hyperspectral reflectance.In this paper,we present the work done to compare the Chl predictive quality by various red-edge-based vegetation indices based on the CASI data.The results indicated that among the selected vegetation indices,TCARI/OSAVI-based model estimated Chl(R2=0.46,RMSE=0.60 and P<0.01)with the best accuracy.To search the optimal vegetation index for Chl estimation,the normalized difference spectral index(NDSI)and ratio spectral index(RSI)were developed by using the waveband combination algorithm.A high linear correlation(R2=0.79,RMSE=0.38 and P<0.01)was acquired by combining the 869.20 and 754.90 nm wavebands,then NDSI(869.20,754.90)was applied to the CASI image to generate the Chl distribution map.It suggests that more fertilizer should be provided for the southwest areas due to the lower Chl.
