The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of th...The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.展开更多
[Objective] This study was to investigate the effects of different irrigation amount on water consumption and water use efficiency of greenhouse cucumber.[Method]Under the condition of drip irrigation with different w...[Objective] This study was to investigate the effects of different irrigation amount on water consumption and water use efficiency of greenhouse cucumber.[Method]Under the condition of drip irrigation with different water amounts in sunlight greenhouse of the arid areas in Ningxia,the soil water was measured and the water consumption of crop was calculated.[Result]When irrigation amount was 563 mm,the water consumption as a whole gradually increased with the delay of growth period,reached peak during the thriving stage of fruit setting,and then gradually declined;in each treatment,the daily water consumption increased with the increasing of irrigation amount during each growth period.However,the consumption of soil moisture reduced with the significant increase of irrigation.563 mm of irrigation amount could meet the water requirements of cucumber and began to add water to soil,and water utilization efficiency could reach 33.4 kg/m3.[Conclusion]The research had provided theoretical basis for water management in the production process of greenhouse cucumber.展开更多
[Objective] This study was conducted to investigate the effect of soil moisture on the growth and water utilization of Chinese kale. [Method] The law of water absorption and utilization of Chinese kale was researched ...[Objective] This study was conducted to investigate the effect of soil moisture on the growth and water utilization of Chinese kale. [Method] The law of water absorption and utilization of Chinese kale was researched under the same irri- gation frequency and different irrigation maximums. [Result] Soil water deficit re- duced water contents in plants in seedling stage and in plants and various organs in maturation stage; water consumption of individual plant was the lowest in 55% treatment of soil A and 45% treatment of soil B, which showed the values of 2.244 and 2.235 L/plant, respectively, and saved water by 23.91% and 21.14% compared with CK; water use efficiencies of soil A with a water content of 55% and soil B with a water content of 35% were the highest, i.e., 6.043 and 5.958 g/L, which were higher than that of CK by 20.09% and 41.72%, respectively; and regulated deficit irrigation also improved irrigation water productivity, and the two kinds of soil both showed in 75% treatments the highest irrigation water productivities, i.e., 40.44 and 40.49 g/L, which were higher than that of CK by 5.64% and 13.39%, respec- tively. [Conclusion[ Controlling irrigation maximum could save water consumed by Chinese kale, improve water use efficiency and improve yield and quality.展开更多
[Objective] The effects of different tillage techniques on dry matter accu- mulation, soil water content, water use efficiency and yield of broomcom millet were studied. [Method] With Jinsu 9 as an experiment material...[Objective] The effects of different tillage techniques on dry matter accu- mulation, soil water content, water use efficiency and yield of broomcom millet were studied. [Method] With Jinsu 9 as an experiment material, the effects of deep tillage, traditional tillage and no tillage and rotary tillage on dry matter accumulation, soil water content, water use efficiency and yield of broomcom millet were investi- gated. [Result] Dry matter accumulation rate and accumulated amount were signifi- cantly higher in the deep tillage, no tillage and rotary tillage treatments than in the conventional tillage treatment, and the highest in the deep tillage treatment. The soil water content of the deep tillage treatment at 0-100 cm was higher than those of other tillage techniques, deep tillage also exhibited the highest soil water storage, and water use efficiency values were in order of deep tillage〉rotary tillage〉no tillage〉conventional tillage. The deep tillage treatment also showed the highest grain weight per spike, 1 000-grain weight and yield, while conventional tillage exhibited the lowest values, indicating that deep tillage is most beneficial to improvement of yield and water use efficiency of broomcom millet. [Conclusion] This study provides a scientific basis for water use efficiency of broomcorh millet in its main producing areas.展开更多
At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, thi...At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, this report reviewed the research advances in water and fertiIizer coupIing, the conception of water and fertiIizer cou-pIing and its three kinds of effects （synergy, antagonism, superposition）, mechanism of water and fertiIizer coupIing, effects of water and fertiIizer coupIing on growth, deveIopment, yield and quality of rice and effects of water and fertiIizer coupIing on utiIization rate of nitrogen in rice. In addition, the deveIopment prospects of water and fertiIizer coupIing in China were described. It was proposed that the water and fertiIizer coupIing mode is an effective measure to achieve the high yield and quality of rice. According to actual demand, referring to the ideas of promoting fertiIizer with water and reguIating water with fertiIizer, reasonabIe water and fertiIizer cou-pIing mode can be estabIished, thereby improving the utiIization efficiencies of water and fertiIizer. In the premise of saving irrigation water and no increasing fertiIization amount, both high yielding and Iess poI ution can be achieved, providing theoretical and technical basis for water-saving agricuIture and cuItivation and management of rice in future.展开更多
This study aimed to investigate the effects of different irrigation amounts on water consumption and water use efficiency of celery under the condition of drip irrigation, so as to provide a scientific basis for high-...This study aimed to investigate the effects of different irrigation amounts on water consumption and water use efficiency of celery under the condition of drip irrigation, so as to provide a scientific basis for high-yielding, high-quality and highefficiency cultivation and water-saving irrigation of greenhouse celery. Total five irrigation amounts were designed, 117.5 （T1）, 160.0 （T2）, 202.5 （T3）, 245.0 （T4） and 287.5 （CK） mm/hm2, and the effects of different irrigation amounts on yield, water consumption and water use efficiency of celery were studied by plot experiment. The results showed that at the soil depth of 0-40 cm, the soil water storages of different treatments ranked as T3＇s〉T4＇s〉CK＇s〉T2＇s〉T1＇s, and the celery water consumptions ranked as CK＇s〉T4＇s〉T3＇s〉T2＇s〉T1＇s. At the same time, the soil water storage in different treatment group declined with the growth of celery, and finally increased at the harvest period. Among different irrigation amounts, the water use effi- ciency and irrigation water use efficiency all ranked as T1＇s〉T2＇s〉T3＇s〉T4＇s〉CK＇s. The water consumption of celery was positively related to irrigation amount （P〈 0.01）, and was negatively related to water use efficiency （P〈0.01） and irrigation water use efficiency （P〈0.05）. When the irrigation amount was below 253 mm/hm2, the celery yield was positively related to irrigation amount （P〈0.01）. There was also a positive correlation between celery output and irrigation amount. Compared with those of CK, the benefit of the T4 treatment group was equal, and the water consumption was reduced by 14.78%. In high-efficiency solar greenhouse, the irrigation amount of drip-irrigated celery is recommended as 245 mm/hm2.展开更多
The North China Plain （NCP） is one of the most important agricultural re- gions in China, but it is experiencing a serious water-resource crisis due to exces- sive exploitation of groundwater reserves. Improving wat...The North China Plain （NCP） is one of the most important agricultural re- gions in China, but it is experiencing a serious water-resource crisis due to exces- sive exploitation of groundwater reserves. Improving water-use efficiency （WUE） of crops is thought to have good potential for conserving groundwater and in maintain- ing high crop production in the region, In this paper, firstly, strategies for improving WUE of crop cultivars in the NCP were discussed. According to studies on key factors affecting cultivar WUE, stomatal conductance, which has large genotypic variability and differs among cultivars in response to drought, is an important physio- logical trait associating closely with the performance of cultivars in WUE and yield. Higher WUE and higher yield may be obtained through strategies of cultivar adop- tion with appropriate stomatal characteristics suitable to different conditions of water availability. Secondly, irrigation scheduling in the North China Plain was further dis- cussed. The irrigation frequency currently employed in this area could be reduced by at least one application （from four to three applications） to obtain higher produc- tion and also higher WUE. Finally, straw mulching and the use of early vigor culti- vats were suggested as two practices that had the potential to be effective in in- creasing crop WUE.展开更多
To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in toler...To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in tolerance for low_P stress) “IR20” and IR55178_3B_9_3, were cultured in liquid medium supplemented with adequate and low P levels in a greenhouse. Plants were sampled after 6 weeks in culture for measurements of plant dry weight, P concentration, P uptake and P use efficiency under both P sufficient and stress conditions. A total of 179 molecular markers, including 26 RFLPs and 153 AFLPs, mapped on all 12 chromosomes of rice based on the 84 selected genotypes were used to detect the quantitative trait loci (QTLs) underlying tolerance for low_P stress. Three QTLs were detected on chromosomes 6, 7 and 12, respectively, for relative plant dry weight (RPDW) and relative P uptake (RPUP). One of the QTLs flanked by RG9 and RG241 on chromosome 12 had a major effect which explained about 50% of the variations in the two parameters across the population. The results coincided with the QTLs for low_P stress based on relative tillering ability from the same population from a cross between Nipponbare and Kasalath under soil condition. The identical major QTL for P uptake and plant growth under low_P stress in both liquid medium and soil strongly suggests that the ability of P uptake mainly controls rice tolerance for low_P stress.展开更多
Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadlea...Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.展开更多
[Objective] This study was conducted to investigate the effects of different irrigation amounts on rice leaf physiology and water use efficiency. [Method] The irrigation test with three different treatments was carrie...[Objective] This study was conducted to investigate the effects of different irrigation amounts on rice leaf physiology and water use efficiency. [Method] The irrigation test with three different treatments was carried out in the Agrometeo- rological Experimental Station of Nanjing University of Information Science ＆ Technology. [Reset] Under flood irrigation, the rice leaf temperature was lower than wet irrigation by 0.4-0.7 ℃; when the strength of photosynthetically active radiation was in the range of 800-1 800 gmol/（m^2·s）, the average stomatal conductance of rice leaves under flood irrigation was higher than that of the wet irrigation treatment by 0.123-0.183 mol H2O/（m^2·s）, and the leaf water use efficiency was higher than that of the wet irrigation treatment by 0.24 g/kg; after 10：00 every day, the water use efficiency under flood irrigation was always higher than that of the wet irrigation treatment; and compared with the wet irrigation treatment, the rice of the flood irrigation treatments had higher leaf water use efficiency, and final yields were also remarkably improved by 5.89%-13.97%. [Conclusion] This study will provide a practical reference basis for field management.展开更多
A field experiment with four treatments and four replicates in a randomized complete block design was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, of Northwest China from 1998 to ...A field experiment with four treatments and four replicates in a randomized complete block design was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, of Northwest China from 1998 to 2002. The local cropping sequence of wheat, wheat-beans, maize, and wheat over the 4-year period was adopted. A micro-plot study using ^15N-lahelled fertilizer was carried out to determine the fate of applied N fertilizer in the first year. When N fertilizer was applied wheat （years 1, 2 and 4） and maize （year 3） grain yield increased significantly （P 〈 0.05） （〉 30%）, with no significant yield differences in normal rainfall years （Years 1, 2 and 3） for N application at the commonly application rate and at 2/3 of this rate. Grain yield of wheat varied greatly between years, mainly due to variation in annual rainfall. Results of ^15N studies on wheat showed that plants recovered 36.6%-38.4% of the N applied, the N remained in soll （0-40 cm） ranged from 29.2% to 33.6%, and unaccounted-for N was 29.5%-34.2%. The following crop （wheat） recovered 2.1%- 2.8% of the residual N from N applied to the previous wheat crop with recovery generally decreasing in the subsequent three crops （beans, maize and wheat）.展开更多
基金supported by the Second Comprehensive Scientific Research Survey on the Tibetan Plateau[grant number 2019QZKK0103]the National Natural Science Foundation of China[grant numbers 42375071 and 42230610].
文摘The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.
基金Supported by National Key Technology R&D Program of China(2007BAD88B06)~~
文摘[Objective] This study was to investigate the effects of different irrigation amount on water consumption and water use efficiency of greenhouse cucumber.[Method]Under the condition of drip irrigation with different water amounts in sunlight greenhouse of the arid areas in Ningxia,the soil water was measured and the water consumption of crop was calculated.[Result]When irrigation amount was 563 mm,the water consumption as a whole gradually increased with the delay of growth period,reached peak during the thriving stage of fruit setting,and then gradually declined;in each treatment,the daily water consumption increased with the increasing of irrigation amount during each growth period.However,the consumption of soil moisture reduced with the significant increase of irrigation.563 mm of irrigation amount could meet the water requirements of cucumber and began to add water to soil,and water utilization efficiency could reach 33.4 kg/m3.[Conclusion]The research had provided theoretical basis for water management in the production process of greenhouse cucumber.
基金Supported by Science and Technology Planning Project of Guangdong Province:Application Research and Demonstration of Automatic Irrigation based on Testing Soil Moisture in Vegetable Production(2015A020209068)Special Fund for Agro-scientific Research in the Public Interest:Research on High-efficiency Vegetable Cultivation and Typical Vegetable Field Non-point Source Pollution Control Technique in South China,Comprehensive Technical Solution for Non-point Source Pollution by Chemical Fertilizer in Farmland(201502103)~~
文摘[Objective] This study was conducted to investigate the effect of soil moisture on the growth and water utilization of Chinese kale. [Method] The law of water absorption and utilization of Chinese kale was researched under the same irri- gation frequency and different irrigation maximums. [Result] Soil water deficit re- duced water contents in plants in seedling stage and in plants and various organs in maturation stage; water consumption of individual plant was the lowest in 55% treatment of soil A and 45% treatment of soil B, which showed the values of 2.244 and 2.235 L/plant, respectively, and saved water by 23.91% and 21.14% compared with CK; water use efficiencies of soil A with a water content of 55% and soil B with a water content of 35% were the highest, i.e., 6.043 and 5.958 g/L, which were higher than that of CK by 20.09% and 41.72%, respectively; and regulated deficit irrigation also improved irrigation water productivity, and the two kinds of soil both showed in 75% treatments the highest irrigation water productivities, i.e., 40.44 and 40.49 g/L, which were higher than that of CK by 5.64% and 13.39%, respec- tively. [Conclusion[ Controlling irrigation maximum could save water consumed by Chinese kale, improve water use efficiency and improve yield and quality.
基金Supported by Youth Scientific Research Fund of Shanxi Province(2014021031-2)Fund for National System of Broomcorn Millet Industrial Technology of Ministry of Agriculture(CARS-07-13.5)~~
文摘[Objective] The effects of different tillage techniques on dry matter accu- mulation, soil water content, water use efficiency and yield of broomcom millet were studied. [Method] With Jinsu 9 as an experiment material, the effects of deep tillage, traditional tillage and no tillage and rotary tillage on dry matter accumulation, soil water content, water use efficiency and yield of broomcom millet were investi- gated. [Result] Dry matter accumulation rate and accumulated amount were signifi- cantly higher in the deep tillage, no tillage and rotary tillage treatments than in the conventional tillage treatment, and the highest in the deep tillage treatment. The soil water content of the deep tillage treatment at 0-100 cm was higher than those of other tillage techniques, deep tillage also exhibited the highest soil water storage, and water use efficiency values were in order of deep tillage〉rotary tillage〉no tillage〉conventional tillage. The deep tillage treatment also showed the highest grain weight per spike, 1 000-grain weight and yield, while conventional tillage exhibited the lowest values, indicating that deep tillage is most beneficial to improvement of yield and water use efficiency of broomcom millet. [Conclusion] This study provides a scientific basis for water use efficiency of broomcorh millet in its main producing areas.
基金Supported by National Key Technology Research and Development Program(2011BAD16B01,2012BAD04B10,2013BAD07B11)~~
文摘At present, the shortage of agricuItural water resources is worsening. In order to reduce the rice irrigation water and improve the utiIization of fertiIizers so as to achieve the high and stabIe yielding of rice, this report reviewed the research advances in water and fertiIizer coupIing, the conception of water and fertiIizer cou-pIing and its three kinds of effects （synergy, antagonism, superposition）, mechanism of water and fertiIizer coupIing, effects of water and fertiIizer coupIing on growth, deveIopment, yield and quality of rice and effects of water and fertiIizer coupIing on utiIization rate of nitrogen in rice. In addition, the deveIopment prospects of water and fertiIizer coupIing in China were described. It was proposed that the water and fertiIizer coupIing mode is an effective measure to achieve the high yield and quality of rice. According to actual demand, referring to the ideas of promoting fertiIizer with water and reguIating water with fertiIizer, reasonabIe water and fertiIizer cou-pIing mode can be estabIished, thereby improving the utiIization efficiencies of water and fertiIizer. In the premise of saving irrigation water and no increasing fertiIization amount, both high yielding and Iess poI ution can be achieved, providing theoretical and technical basis for water-saving agricuIture and cuItivation and management of rice in future.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest of China(201303133-3)Tianjin Science and Technology Plan Project(14ZCDGNC00108)Agricultural Science and Technology Achievements Transformation and Extension Project of Tianjin City(201203030)~~
文摘This study aimed to investigate the effects of different irrigation amounts on water consumption and water use efficiency of celery under the condition of drip irrigation, so as to provide a scientific basis for high-yielding, high-quality and highefficiency cultivation and water-saving irrigation of greenhouse celery. Total five irrigation amounts were designed, 117.5 （T1）, 160.0 （T2）, 202.5 （T3）, 245.0 （T4） and 287.5 （CK） mm/hm2, and the effects of different irrigation amounts on yield, water consumption and water use efficiency of celery were studied by plot experiment. The results showed that at the soil depth of 0-40 cm, the soil water storages of different treatments ranked as T3＇s〉T4＇s〉CK＇s〉T2＇s〉T1＇s, and the celery water consumptions ranked as CK＇s〉T4＇s〉T3＇s〉T2＇s〉T1＇s. At the same time, the soil water storage in different treatment group declined with the growth of celery, and finally increased at the harvest period. Among different irrigation amounts, the water use effi- ciency and irrigation water use efficiency all ranked as T1＇s〉T2＇s〉T3＇s〉T4＇s〉CK＇s. The water consumption of celery was positively related to irrigation amount （P〈 0.01）, and was negatively related to water use efficiency （P〈0.01） and irrigation water use efficiency （P〈0.05）. When the irrigation amount was below 253 mm/hm2, the celery yield was positively related to irrigation amount （P〈0.01）. There was also a positive correlation between celery output and irrigation amount. Compared with those of CK, the benefit of the T4 treatment group was equal, and the water consumption was reduced by 14.78%. In high-efficiency solar greenhouse, the irrigation amount of drip-irrigated celery is recommended as 245 mm/hm2.
基金Supported by Grants from the Ministry of Science and Technology of China(2011AA100501)the National Natural Science Foundation of China(30871447)~~
文摘The North China Plain （NCP） is one of the most important agricultural re- gions in China, but it is experiencing a serious water-resource crisis due to exces- sive exploitation of groundwater reserves. Improving water-use efficiency （WUE） of crops is thought to have good potential for conserving groundwater and in maintain- ing high crop production in the region, In this paper, firstly, strategies for improving WUE of crop cultivars in the NCP were discussed. According to studies on key factors affecting cultivar WUE, stomatal conductance, which has large genotypic variability and differs among cultivars in response to drought, is an important physio- logical trait associating closely with the performance of cultivars in WUE and yield. Higher WUE and higher yield may be obtained through strategies of cultivar adop- tion with appropriate stomatal characteristics suitable to different conditions of water availability. Secondly, irrigation scheduling in the North China Plain was further dis- cussed. The irrigation frequency currently employed in this area could be reduced by at least one application （from four to three applications） to obtain higher produc- tion and also higher WUE. Finally, straw mulching and the use of early vigor culti- vats were suggested as two practices that had the potential to be effective in in- creasing crop WUE.
文摘To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in tolerance for low_P stress) “IR20” and IR55178_3B_9_3, were cultured in liquid medium supplemented with adequate and low P levels in a greenhouse. Plants were sampled after 6 weeks in culture for measurements of plant dry weight, P concentration, P uptake and P use efficiency under both P sufficient and stress conditions. A total of 179 molecular markers, including 26 RFLPs and 153 AFLPs, mapped on all 12 chromosomes of rice based on the 84 selected genotypes were used to detect the quantitative trait loci (QTLs) underlying tolerance for low_P stress. Three QTLs were detected on chromosomes 6, 7 and 12, respectively, for relative plant dry weight (RPDW) and relative P uptake (RPUP). One of the QTLs flanked by RG9 and RG241 on chromosome 12 had a major effect which explained about 50% of the variations in the two parameters across the population. The results coincided with the QTLs for low_P stress based on relative tillering ability from the same population from a cross between Nipponbare and Kasalath under soil condition. The identical major QTL for P uptake and plant growth under low_P stress in both liquid medium and soil strongly suggests that the ability of P uptake mainly controls rice tolerance for low_P stress.
基金The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX-406-4 KZCX1SW01 of the Chinese Academy of Sciences
文摘Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.
文摘[Objective] This study was conducted to investigate the effects of different irrigation amounts on rice leaf physiology and water use efficiency. [Method] The irrigation test with three different treatments was carried out in the Agrometeo- rological Experimental Station of Nanjing University of Information Science ＆ Technology. [Reset] Under flood irrigation, the rice leaf temperature was lower than wet irrigation by 0.4-0.7 ℃; when the strength of photosynthetically active radiation was in the range of 800-1 800 gmol/（m^2·s）, the average stomatal conductance of rice leaves under flood irrigation was higher than that of the wet irrigation treatment by 0.123-0.183 mol H2O/（m^2·s）, and the leaf water use efficiency was higher than that of the wet irrigation treatment by 0.24 g/kg; after 10：00 every day, the water use efficiency under flood irrigation was always higher than that of the wet irrigation treatment; and compared with the wet irrigation treatment, the rice of the flood irrigation treatments had higher leaf water use efficiency, and final yields were also remarkably improved by 5.89%-13.97%. [Conclusion] This study will provide a practical reference basis for field management.
基金Project supported by the International Atom Energy Agency (IAEA) (NO. 302-D1-CRP-9986) and the National Basic Research Program of China (NO. 2005CB121102).
文摘A field experiment with four treatments and four replicates in a randomized complete block design was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, of Northwest China from 1998 to 2002. The local cropping sequence of wheat, wheat-beans, maize, and wheat over the 4-year period was adopted. A micro-plot study using ^15N-lahelled fertilizer was carried out to determine the fate of applied N fertilizer in the first year. When N fertilizer was applied wheat （years 1, 2 and 4） and maize （year 3） grain yield increased significantly （P 〈 0.05） （〉 30%）, with no significant yield differences in normal rainfall years （Years 1, 2 and 3） for N application at the commonly application rate and at 2/3 of this rate. Grain yield of wheat varied greatly between years, mainly due to variation in annual rainfall. Results of ^15N studies on wheat showed that plants recovered 36.6%-38.4% of the N applied, the N remained in soll （0-40 cm） ranged from 29.2% to 33.6%, and unaccounted-for N was 29.5%-34.2%. The following crop （wheat） recovered 2.1%- 2.8% of the residual N from N applied to the previous wheat crop with recovery generally decreasing in the subsequent three crops （beans, maize and wheat）.
