A deep understanding of crop-water eco-physiological relations is the basis for quantifying plant physiological responses to soil water stress. Pot experiments were conducted to investigate the winter wheat crop-water...A deep understanding of crop-water eco-physiological relations is the basis for quantifying plant physiological responses to soil water stress. Pot experiments were conducted to investigate the winter wheat crop-water relations under both drought and waterlogging conditions in two sequential growing seasons from 2000 to 2002, and then the data were used to develop and validate models simulating the responses of winter wheat growth to drought and waterlogging stress. The experiment consisted of four treatments, waterlogging (keep 1 to 2 cm water layer depth above soil surface), control (70%-80% field capacity), light drought (40%-50% field capacity) and severe drought (30%-40% field capacity) with six replicates at five stages in the 2000-2001 growth season. Three soil water content treatments (waterlogging, control and drought) with two replicates were designed in the 2001-2002 growth season. Waterlogging and control treatments are the same as in the 2000-2001 growth season. For the drought treatment, no water was supplied and the soil moisture decreased from field capacity to wilting point. Leaf net photosynthetic rate, transpiration rate, predawn leaf water potential, soil water potential, soil water content and dry matter weight of individual organs were measured. Based on crop-water eco-physiological relations, drought and waterlogging stress factors for winter wheat growth simulation model were put forward. Drought stress factors integrated soil water availability, the sensitivity of different development stages and the difference between physiological processes (such as photosynthesis, transpiration and partitioning). The quantification of waterlogging stress factor considered different crop species, soil water status, waterlogging days and sensitivity at different growth stages. Data sets from the pot experiments revealed favorable performance reliability for the simulation sub-models with the drought and waterlogging stress factors.展开更多
Undisturbed soil core with many macropores and disturbed soil core with onlyone macropore (diameter is 10 mm) were probed by X-ray computed tomography (CT). The size, number,shape and continuity of macropores in the t...Undisturbed soil core with many macropores and disturbed soil core with onlyone macropore (diameter is 10 mm) were probed by X-ray computed tomography (CT). The size, number,shape and continuity of macropores in the transverse and vertical sectionsof soil were characterizedusing CT scanning images. The probability densities of macropores in the transverse section of soilcore exhibited a logarithmic P distribution. Results indicated that CT scanning was a promisingnondestructive method for characterizing macropores in soils.展开更多
Objective: To construct eukaryotic expression plasmid pcDNA3-fragile histidine triad(FHIT) and obtain its transient expression in COS-1 cells. Methods: FHIT gene was cloned from normal human thyroid tissue by RT-PCR a...Objective: To construct eukaryotic expression plasmid pcDNA3-fragile histidine triad(FHIT) and obtain its transient expression in COS-1 cells. Methods: FHIT gene was cloned from normal human thyroid tissue by RT-PCR and then inserted into eukaryotic expression vector pcDNA3. After the sequence was confirmed, the recombinant plasmid pcDNA3-FHIT was transfected into COS-1 cells by cation liposome. The transient expression in the cells was measured by immunocytochemistry. Results: The sequence of FHIT in pcDNA3 was correct and high expression was obtained in COS-1 cells. Conclusion: The eukaryotic expression plasmid pcDNA3-FHIT was constructed successfully and could highly express FHIT protein in COS-1 cells. This will be potentially useful for the research on gene therapy.展开更多
基金Project supported by the National High Technology Research and Development Program of China (863 Program) (No. 2003AA209030) High Technology Research and Development Program of Jiangsu Province (No. BG2004320) the National Natural Science Foundation
文摘A deep understanding of crop-water eco-physiological relations is the basis for quantifying plant physiological responses to soil water stress. Pot experiments were conducted to investigate the winter wheat crop-water relations under both drought and waterlogging conditions in two sequential growing seasons from 2000 to 2002, and then the data were used to develop and validate models simulating the responses of winter wheat growth to drought and waterlogging stress. The experiment consisted of four treatments, waterlogging (keep 1 to 2 cm water layer depth above soil surface), control (70%-80% field capacity), light drought (40%-50% field capacity) and severe drought (30%-40% field capacity) with six replicates at five stages in the 2000-2001 growth season. Three soil water content treatments (waterlogging, control and drought) with two replicates were designed in the 2001-2002 growth season. Waterlogging and control treatments are the same as in the 2000-2001 growth season. For the drought treatment, no water was supplied and the soil moisture decreased from field capacity to wilting point. Leaf net photosynthetic rate, transpiration rate, predawn leaf water potential, soil water potential, soil water content and dry matter weight of individual organs were measured. Based on crop-water eco-physiological relations, drought and waterlogging stress factors for winter wheat growth simulation model were put forward. Drought stress factors integrated soil water availability, the sensitivity of different development stages and the difference between physiological processes (such as photosynthesis, transpiration and partitioning). The quantification of waterlogging stress factor considered different crop species, soil water status, waterlogging days and sensitivity at different growth stages. Data sets from the pot experiments revealed favorable performance reliability for the simulation sub-models with the drought and waterlogging stress factors.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. G1999011803) the Knowledge Innovation Program of the Chinese Academy of Sciences (No. K2CX2-404)the Science and Technology Innovation Program of Hohai
文摘Undisturbed soil core with many macropores and disturbed soil core with onlyone macropore (diameter is 10 mm) were probed by X-ray computed tomography (CT). The size, number,shape and continuity of macropores in the transverse and vertical sectionsof soil were characterizedusing CT scanning images. The probability densities of macropores in the transverse section of soilcore exhibited a logarithmic P distribution. Results indicated that CT scanning was a promisingnondestructive method for characterizing macropores in soils.
文摘Objective: To construct eukaryotic expression plasmid pcDNA3-fragile histidine triad(FHIT) and obtain its transient expression in COS-1 cells. Methods: FHIT gene was cloned from normal human thyroid tissue by RT-PCR and then inserted into eukaryotic expression vector pcDNA3. After the sequence was confirmed, the recombinant plasmid pcDNA3-FHIT was transfected into COS-1 cells by cation liposome. The transient expression in the cells was measured by immunocytochemistry. Results: The sequence of FHIT in pcDNA3 was correct and high expression was obtained in COS-1 cells. Conclusion: The eukaryotic expression plasmid pcDNA3-FHIT was constructed successfully and could highly express FHIT protein in COS-1 cells. This will be potentially useful for the research on gene therapy.
