After water stress at various levels and durations at different growth stages, rewatering could greatly stimulate the leaf area development of winter wheat. The results showed that the stimulation effect changed with ...After water stress at various levels and durations at different growth stages, rewatering could greatly stimulate the leaf area development of winter wheat. The results showed that the stimulation effect changed with water stress time, degree and duration. Rewatering under earlier stress had greater stimulation effect on leaf area than that under later stress. Higher stimulation effect was observed under severe water stress than that under moderate stress. Longer duration of stress resulted in low stimulation effect. In spite of the greater stimulation effect under severe and longer stress, the final leaf area in these situations was lower than that under moderate stress and shorter duration. Whenever the stress occurred, the stimulating effect was due to the increase of the leaf area of the tillers. Once the leaf on the main stem emerged during stress period, rewatering had no effect on its size, and consequently its leaf area. The stimulation of rewateirng on leaf area contributed to the final grain yield by 45% under moderate stress, and 67% under severe stress. Although the stimulation partly compensated for the loss during stress, the final leaf area and the grain yield could not reach the level without water stress.展开更多
To reveal the period and after-effect of soil water stress on winter wheat, the article employs the experiment results carried out in the greenhouse. The results showed that the root-restricted weights varied with str...To reveal the period and after-effect of soil water stress on winter wheat, the article employs the experiment results carried out in the greenhouse. The results showed that the root-restricted weights varied with stress degrees and stress times during and after water stressing. In the course of stress, the chief reason resticting the weight of root was the stress intensity at this time, and that of severe stress treatment was larger than that of mild stress treatment. After water stress was relieved, the results of the after-effect of soil water stress on root growth were that, the stress intensity of short-time and mild stress was larger than that of long-time and severe stress. Comparing two-stage stress intensities, root-restricted weight resulted from after-effect intensity of stress under all of the short-time treatment, and the mild and the long-time stress treatments, while that resulted from the period stress intensity under the severe and the long-time stress treatments. In general, the effects of water stress on root were attributed to the three factors, a formed basis in the previous stage, the after-effect of water condition before this stage and influence of water in this stage, which lead to the characters of root in the whole growth stage.展开更多
Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water ...Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water potential(LWP)and saturated osmotic potential (LSOP) were positively correlated to soil relative water content (SRWC) and decreased as SRWC descended at each growth stage,and the decreasing range exhibited B. N. 2【J. 411. The turgor pressure(TP)of both the varieties decreased less than LRWC and LWP. It was shown that both varieties had a osmotic adjustment ability(OAA) ,and the decreasing range presented B. N. 2【J. 411. Both the varieties had a TP tubercle in TP vs SRWC graph at heading and filling stages,and their OAA was the strongest at these two stages.展开更多
Wheat(Triticum aestivum L.) is one of the three major global food crops. Hightemperature stress can affect its yield and quality. Studies of the effect of hightemperature stress on wheat kernel development are importa...Wheat(Triticum aestivum L.) is one of the three major global food crops. Hightemperature stress can affect its yield and quality. Studies of the effect of hightemperature stress on wheat kernel development are important because they can reveal the stability of wheat quality and lead to the genetic improvement of wheat quality traits. In this study, the isobaric tags for relative and absolute quantitation(iTRAQ)method was adopted to analyze changes in the protein expression profile of wheat cultivars under high temperature stress. The protein content of wheat grain increased under heat stress, while the SDS-sedimentation value and starch content decreased.Grain filling was deficient under high temperature stress, which reduced thousandkernel weight but did not affect wheat kernel length. The 207 differentially expressed proteins identified in Gaocheng 8901 under heat stress were associated with energy metabolism, growth and development, and stress response. Gene Ontology enrichment analysis showed that the annotated proteins that were differentially expressed in Gaocheng 8901 under heat stress were involved mainly in stimulus response, abiotic stress response, stress response, and plasma membrane. A set of 78 differentially expressed proteins were assigned to 83 KEGG signaling/metabolic pathways. KEGG pathway enrichment analysis showed that this set of proteins was significantly enriched in members of 51 pathways, and the proteins participated mainly in protein synthesis in the endoplasmic reticulum, starch and sucrose metabolism, and reaction on ribosomes. Five differentially expressed proteins were involved in protein–protein interaction networks that may greatly influence the yield and quality of wheat grain. In wheat, high-temperature stress leads to a variety of effects on protein expression and may ultimately cause changes in yield and quality.展开更多
The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL...The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL L^-1. The results indicated that new FA antitranspirant increased nitrate reductase activity （NRA）, free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis, enlarged stomatal conductance and reduced transpiration rate, thus led to growth stimulation and water loss reduction. New FA antitranspirant caused an increase of grain yield by 7.2%, under the optimal concentration 1.5 mL L^-1.展开更多
On the basis of hydrographic data obtained in November 28 to December 27, 1998 cruise, the calculation of the circulation in the South China Sea (SCS) is made by using the P-vector method, in combination with SSH data...On the basis of hydrographic data obtained in November 28 to December 27, 1998 cruise, the calculation of the circulation in the South China Sea (SCS) is made by using the P-vector method, in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of winter circulation in the SCS, the diagnostic model (Yuan et al., 1982; Yuan and Su, 1992) is used to simulate numerically the winter circulation in the SCS. The following results have been obtained. (1) The main characteristics of the circulation systems in the central SCS are as follows: A coastal southward jet in winter is present at the western boundary near the coast of Vietnam; there is a stronger cyclonic circulation with a larger horizontal scale east of this coastal southward jet and west of 114°E; there is a weaker anti-cyclonic circulation in the central part of eastern SCS; there is a stronger and northeastward flow opposing the northeasterly monsoon between above a stronger cyclonic circulation and a weaker anti-cyclonic circulation. (2) The circulation systems in the northern SCS are as follows: 1) There is a cyclonic circulation system northwest of Luzon, and it has three centers of the cold water; 2) There is an anti-cyclonic eddy. Its center is located near(20°N, 116°40' E); 3)There is a warm and anti-cyclonic circulation south of Hainan Island; 4) There is a northeastward flow, the South China Sea Warm Current, in winter off Guangdong coast in the northern SCS. (3) In the southern SCS there is an anti-cyclonic circulation, and also there is a smaller scale cold water and cyclonic eddy. (4) The above pattern of winter circulation in the SCS agrees qualitatively with the horizontal distribution of temperature at 200 m level. (5) The dynamical mechanism which produces the above basic pattern of winter circulation is because of the following two causes: 1) The joint effect of the baroclinity and relief (JEBAR) is an essential dynamical cause; 2) The interaction between the wind stress and bottom topographic (IBWT) under the strong northeasterly monsoon is the next important dynamical mechanism. (6) Comparing the hydrographic structure and the horizontal distribution of velocity with the SSH data from TOPEX/ERS-2 analysis in the SCS during December of 1998, it is found that they agree qualitatively.展开更多
基金National Fundamental Research and Development (No. G1999011709 ) the National Natural Science Foundation (No.49971042).
文摘After water stress at various levels and durations at different growth stages, rewatering could greatly stimulate the leaf area development of winter wheat. The results showed that the stimulation effect changed with water stress time, degree and duration. Rewatering under earlier stress had greater stimulation effect on leaf area than that under later stress. Higher stimulation effect was observed under severe water stress than that under moderate stress. Longer duration of stress resulted in low stimulation effect. In spite of the greater stimulation effect under severe and longer stress, the final leaf area in these situations was lower than that under moderate stress and shorter duration. Whenever the stress occurred, the stimulating effect was due to the increase of the leaf area of the tillers. Once the leaf on the main stem emerged during stress period, rewatering had no effect on its size, and consequently its leaf area. The stimulation of rewateirng on leaf area contributed to the final grain yield by 45% under moderate stress, and 67% under severe stress. Although the stimulation partly compensated for the loss during stress, the final leaf area and the grain yield could not reach the level without water stress.
基金the Ministry of Science and Technology of China （1999011700） the National Natural Science Foundation of China （49971042）.
文摘To reveal the period and after-effect of soil water stress on winter wheat, the article employs the experiment results carried out in the greenhouse. The results showed that the root-restricted weights varied with stress degrees and stress times during and after water stressing. In the course of stress, the chief reason resticting the weight of root was the stress intensity at this time, and that of severe stress treatment was larger than that of mild stress treatment. After water stress was relieved, the results of the after-effect of soil water stress on root growth were that, the stress intensity of short-time and mild stress was larger than that of long-time and severe stress. Comparing two-stage stress intensities, root-restricted weight resulted from after-effect intensity of stress under all of the short-time treatment, and the mild and the long-time stress treatments, while that resulted from the period stress intensity under the severe and the long-time stress treatments. In general, the effects of water stress on root were attributed to the three factors, a formed basis in the previous stage, the after-effect of water condition before this stage and influence of water in this stage, which lead to the characters of root in the whole growth stage.
文摘Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water potential(LWP)and saturated osmotic potential (LSOP) were positively correlated to soil relative water content (SRWC) and decreased as SRWC descended at each growth stage,and the decreasing range exhibited B. N. 2【J. 411. The turgor pressure(TP)of both the varieties decreased less than LRWC and LWP. It was shown that both varieties had a osmotic adjustment ability(OAA) ,and the decreasing range presented B. N. 2【J. 411. Both the varieties had a TP tubercle in TP vs SRWC graph at heading and filling stages,and their OAA was the strongest at these two stages.
基金supported by the National Key Research and Development Program of China(2016YFD0100502)
文摘Wheat(Triticum aestivum L.) is one of the three major global food crops. Hightemperature stress can affect its yield and quality. Studies of the effect of hightemperature stress on wheat kernel development are important because they can reveal the stability of wheat quality and lead to the genetic improvement of wheat quality traits. In this study, the isobaric tags for relative and absolute quantitation(iTRAQ)method was adopted to analyze changes in the protein expression profile of wheat cultivars under high temperature stress. The protein content of wheat grain increased under heat stress, while the SDS-sedimentation value and starch content decreased.Grain filling was deficient under high temperature stress, which reduced thousandkernel weight but did not affect wheat kernel length. The 207 differentially expressed proteins identified in Gaocheng 8901 under heat stress were associated with energy metabolism, growth and development, and stress response. Gene Ontology enrichment analysis showed that the annotated proteins that were differentially expressed in Gaocheng 8901 under heat stress were involved mainly in stimulus response, abiotic stress response, stress response, and plasma membrane. A set of 78 differentially expressed proteins were assigned to 83 KEGG signaling/metabolic pathways. KEGG pathway enrichment analysis showed that this set of proteins was significantly enriched in members of 51 pathways, and the proteins participated mainly in protein synthesis in the endoplasmic reticulum, starch and sucrose metabolism, and reaction on ribosomes. Five differentially expressed proteins were involved in protein–protein interaction networks that may greatly influence the yield and quality of wheat grain. In wheat, high-temperature stress leads to a variety of effects on protein expression and may ultimately cause changes in yield and quality.
文摘The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL L^-1. The results indicated that new FA antitranspirant increased nitrate reductase activity （NRA）, free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis, enlarged stomatal conductance and reduced transpiration rate, thus led to growth stimulation and water loss reduction. New FA antitranspirant caused an increase of grain yield by 7.2%, under the optimal concentration 1.5 mL L^-1.
基金This work is supported by the Major State Basic Research Program of China under contract No.G 1999043805.
文摘On the basis of hydrographic data obtained in November 28 to December 27, 1998 cruise, the calculation of the circulation in the South China Sea (SCS) is made by using the P-vector method, in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of winter circulation in the SCS, the diagnostic model (Yuan et al., 1982; Yuan and Su, 1992) is used to simulate numerically the winter circulation in the SCS. The following results have been obtained. (1) The main characteristics of the circulation systems in the central SCS are as follows: A coastal southward jet in winter is present at the western boundary near the coast of Vietnam; there is a stronger cyclonic circulation with a larger horizontal scale east of this coastal southward jet and west of 114°E; there is a weaker anti-cyclonic circulation in the central part of eastern SCS; there is a stronger and northeastward flow opposing the northeasterly monsoon between above a stronger cyclonic circulation and a weaker anti-cyclonic circulation. (2) The circulation systems in the northern SCS are as follows: 1) There is a cyclonic circulation system northwest of Luzon, and it has three centers of the cold water; 2) There is an anti-cyclonic eddy. Its center is located near(20°N, 116°40' E); 3)There is a warm and anti-cyclonic circulation south of Hainan Island; 4) There is a northeastward flow, the South China Sea Warm Current, in winter off Guangdong coast in the northern SCS. (3) In the southern SCS there is an anti-cyclonic circulation, and also there is a smaller scale cold water and cyclonic eddy. (4) The above pattern of winter circulation in the SCS agrees qualitatively with the horizontal distribution of temperature at 200 m level. (5) The dynamical mechanism which produces the above basic pattern of winter circulation is because of the following two causes: 1) The joint effect of the baroclinity and relief (JEBAR) is an essential dynamical cause; 2) The interaction between the wind stress and bottom topographic (IBWT) under the strong northeasterly monsoon is the next important dynamical mechanism. (6) Comparing the hydrographic structure and the horizontal distribution of velocity with the SSH data from TOPEX/ERS-2 analysis in the SCS during December of 1998, it is found that they agree qualitatively.
