Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could ...Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22.展开更多
[Objective] The aim was to explore the effects of low night temperature treatment on sucrose synthesis ability of tomato leaves in seedling stage.[Method] Effects of low night temperature of 6 ℃(with 15 ℃ as contro...[Objective] The aim was to explore the effects of low night temperature treatment on sucrose synthesis ability of tomato leaves in seedling stage.[Method] Effects of low night temperature of 6 ℃(with 15 ℃ as control)on the sucrose synthesis ability of tomato leaves were studied after 1,3,5,7 d of treatment.[Result] The contents of fructose,glucose and sucrose in tomato leaves were higher than control at 6:00 during the treatment of low night temperature,but in contrast at 11:00.The contents of fructose,glucose and sucrose in tomato leaves of low night temperature treatment and control group at 6:00 were lower than that at 11:00.The content of starch in tomato leaves was higher than control at 6:00 and 11:00 during the treatment.And the activities of sugar metabolism enzymes of tomato were changed by the treatment of low night temperature.The activities of acid invertase(AI)and neutral invertase(NI)were higher than those of control,while the activities of sucrose synthase(SS)and sucrose phosphate synthase(SPS)were lower than control at 6:00 and 11:00 during the treatment.The activity of all the enzymes at 11:00 of low night temperature treatment plants treated for 1,3,5,7 d was higher than that at 6:00.Compared to 6:00,the invertase activity of the control plant decreased,while the synthetase activity increased.The activity of sucrose synthase(SS)was decreased for treated plants,and the increase amount of sucrose content in leaves was lower than that of control at 11:00 during the treatment,indicating that the sucrose synthesis ability of tomato leaves was decreased by the treatment of low night temperature.[Conclusion] The results in this study had provided theoretical basis for the environmental control of high-yield cultivation of tomato.展开更多
The effects of different levels of CaCl 2 on photosynthesis under low night temperature(8°C) stress in peanuts were studied in order to find out the appropriate concentration of Ca2+through the artificial clim...The effects of different levels of CaCl 2 on photosynthesis under low night temperature(8°C) stress in peanuts were studied in order to find out the appropriate concentration of Ca2+through the artificial climate chamber potted culture test.The results indicated that Ca2+,by means of improving the stomatal conductivity of peanut leaves under low night temperature stress,may mitigate the decline of photosynthetic rate in the peanut leaves.The regulation with 15 mmol L-1CaCl 2(Ca15) was the most effective,compared with other treatments.Subsequently,the improvement of Ca2+on peanut photosynthesis under low night temperature stress was validated further through spraying with Ca15,Ca2+chelator(ethylene glycol bis(2-aminoethyl) tetraacetic acid; EGTA) and calmodulin antagonists(trifluonerazine; TFP).And CaM(Ca2+-modulin) played an important role in the nutritional signal transduction for Ca2+mitigating photosynthesis limitations in peanuts under low night temperature stress.展开更多
Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature inc...Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.展开更多
Temperature integration where high day temperatures are compensated by lower night temperatures is one strategy that can be used to reduce energy consumption in greenhouses. Crop tolerance to temperature variation is ...Temperature integration where high day temperatures are compensated by lower night temperatures is one strategy that can be used to reduce energy consumption in greenhouses. Crop tolerance to temperature variation is a prerequisite for using such a strategy. Greenhouse experiments were conducted on tomatoes cvs, Capricia, Mecano and Cederico in order to investigate the effect of different day/night temperature regimes (24/17, 27/14 and 30/11℃) where the same mean temperature was maintained for the production and germination of pollen. In addition, fruit quality as determined by fruit firmness, dry matter content, soluble solids, titratable acids, and pH was examined at harvest and after seven and 14 days of storage. The 30/11℃ treatment significantly increased pollen production and germination compared to the 24/17℃ treatment, while the 27/14℃ treatment was generally in between the other two treatments. Fruits grown at the 27/14℃ treatment were significantly firmer, while fruits grown at 24/17℃ had higher dry matter content, soluble solids, and titratable acids compared to the other treatments. There were significant differences between cultivars with respect to firmness, dry matter, titratable acidity, and pH. The quality of the fruits changed during storage, but the storability of the tomatoes was not affected by preharvest temperature treatments. The overall conclusion was that the 27/14℃ treatment was superior to the other two temperature treatments with respect to the studied parameters.展开更多
The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthoc...The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.展开更多
Heat stress studies in rice (<em>Oryza sativa</em> sp.) under extreme weather scenarios generally use constant temperatures to influence the crop responses without relation to actual weather changes. These...Heat stress studies in rice (<em>Oryza sativa</em> sp.) under extreme weather scenarios generally use constant temperatures to influence the crop responses without relation to actual weather changes. These heat stress studies may have limited implications for future crop yields because elevated temperatures are not based on local temperature fluctuations. This study investigated the night-time air temperature pattern and assessed the status and reliability of available weather station data in four major rice growing states;Arkansas (AR), California (CA), Louisiana (LA) and Texas (TX) using four public weather station databases. Hourly and daily night-time air temperatures from 20:00 to 06:00 were obtained from 1940 to 2018 during the rice growing period. During the 67-year period, a significant increase of 1.12<span style="white-space:nowrap;">°</span>C and 0.53<span style="white-space:nowrap;">°</span>C in seasonal night air temperature occurred in CA and AR (<em>P</em> ≤ 0.001) while LA and TX showed minimal to no increase in night air temperature. Across all rice states and years, night air temperature fluctuations ranged between ±0.2<span style="white-space:nowrap;">°</span>C and ±4<span style="white-space:nowrap;">°</span>C with the greatest occurred in CA (2.9<span style="white-space:nowrap;">°</span>C) and AR (4.5<span style="white-space:nowrap;">°</span>C). Mean night-time air temperature across all states ranged from 22.6<span style="white-space:nowrap;">°</span>C to 29.5<span style="white-space:nowrap;">°</span>C with a rate of increase of 0.01<span style="white-space:nowrap;">°</span>C to 0.02<span style="white-space:nowrap;">°</span>C per year since 1941. Due to a relatively smaller spatial dataset (from 1941-2018), trend analyses for AR, TX and LA showed modest bias with root mean square errors (RMSE) of 0.5<span style="white-space:nowrap;">°</span>C to 1.1<span style="white-space:nowrap;">°</span>C of absolute mean temperature across all locations. Results in this study showed seasonal night-time air temperature change occurred in some major US rice producing states during the last 67-years. This study highlights the need for more weather stations near agricultural farms to reliably derive actual temperature patterns in the rice growing regions.展开更多
If low night temperatures can be combined with high day temperatures, providing optimal growth conditions for plants, a significant energy saving can be achieved in greenhouses. Lowering the night temperature from 18&...If low night temperatures can be combined with high day temperatures, providing optimal growth conditions for plants, a significant energy saving can be achieved in greenhouses. Lowering the night temperature from 18°C to 10°C-11°C for 8 h had no negative effect on the CO2 exchange rate (CER) during the following light period in tomato. This was found both in plants grown in artificial light only or in combination with daylight. Allowing the temperature to increase from 20°C to about 40°C, in parallel with an increasing solar photon flux density (PFD) from 0 up to about 800 μmol·m-2·s-1 in the greenhouse during summer, progressively increased CER when the CO2 concentration was maintained at 900 μmol·mol-1. At 400 μmol·mol-1 CO2, maximum CER was reached at about 600 μmol·m-2·s-1 PFD combined with a temperature of 32°C, and leveled out with a further increase in PFD and temperature. Maximum CER at high CO2 concentration was around 100% higher than at low CO2 level. Under early autumn conditions, CER increased up to about 500 μmol·m-2·s-1 PFD/32°C at low CO2 and up to about 600 μmol·m-2·s-1 PFD/35°C at high CO2. An elevated CO2 level doubled the CER in this experiment as well. Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis, indicating that no treatment negatively affected the efficiency of the photosynthetic apparatus. The results showed that low night temperatures may be combined with very high day temperatures without any loss of daily photosynthesis particularly in a CO2 enriched atmosphere. If this can be combined with normal plant development and no negative effects on the yield, significant energy savings can be achieved in greenhouses.展开更多
The study aimed at analyzing the trends and variability of temperature extreme</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span st...The study aimed at analyzing the trends and variability of temperature extreme</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> over </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">northeastern highlands in Tanzania, specifically over Arusha and Kilimanjaro regions. Quality controlled mean monthly, daily maximum and minimum temperature data for the period 1961 to 2020</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> obtained from Tanzania Meteorological Authority</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> were used in the study. Rclimdex and the National Climate Monitoring Products (NMCP) software</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> developed by the World Meteorological Organization (WMO)</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> were used for computation of the indices at a monthly, seasonal and annual time scale. The computed indices were also subjected to trend analysis to determine their direction and magnitude of change. Extraction and assessment of the top five highest and lowest maximum and minimum temperature</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> also done. Increasing trends of temperature anomalies for seasonal and annual timescale</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> were observed for both Arusha and Kilimanjaro regions. Also, the increasing trends of warm and extreme warm days and nights and relatively increasing trends of cold and extreme cold days and nights were observed for both regions. The highest ever recorded temperatures since the establishment of the two stations were 36.3?C observed on 16</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> February 2011 and 38.6?C observed on 22</span><sup><span style="font-family:Verdana;">nd</span></sup><span style="font-family:Verdana;"> February 2005 for Arusha and Kilimanjaro respectively. These results indicate that The last two decades have been characterized by enhanced warming, which is consistent with overall global temperature trend patterns as depicted in recent IPCC reports and the report of the State of Climate in Africa.展开更多
[ Objective] The research aimed to study temporal-spatial change characteristics of the extremely low temperature climate event in winter of China. [MethodI By using actual probability distribution threshold value met...[ Objective] The research aimed to study temporal-spatial change characteristics of the extremely low temperature climate event in winter of China. [MethodI By using actual probability distribution threshold value method, EOF analysis method and the daily minimum temperature data in winter of 1961 -2008 at 195 observatories of China, temporal-spatial change characteristics of the extremely low temperature climate event in win- ter of China in 48 years were analyzed. [ Result] Threshold value calculated by actual probability distribution was higher than that by traditional method, and increase magnitude in east was bigger than that in west, which could describe climatic change situation in China in 48 years better than traditional method. Cold night number in winter of China did not decrease as latitude declined, and it was more in south and north and was less in Yellow River basin and northwest China. Cold night number was the most in northeast Inner Mongolia. Interannual change of the cold night number presented decline tendency. From the 1960s to the eady 1970s, cold night number consistently increased, and change in middle and late periods of the 1960s was severe. From the early 1970s to the middle 1980s, fluctuation of the cold night number was bigger, and increase of the cold night number was the most in 1976. Cold night number from 1986 to the 21= century continuously declined. Change of the cold night number was the most obvious in east region, Guizhou and north Guangxi. Cold night number in northeast China and north Inner Mongolia presented inverting change relationship with that in Yunnan - Kweichow Plateau and Hexi Corridor. [ Conclusion] The research provided reference for eady warning of the extremely low temoerature event in China.展开更多
The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature (Tmin) has risen more than twice as fast as the daily maximum temperature (Tmax) during the 20th c...The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature (Tmin) has risen more than twice as fast as the daily maximum temperature (Tmax) during the 20th century. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to in- vestigate how the crops respond to the Train rise. In particular, no experiment research has reported on how crops respond to the higher night temperature, which was the main trend in the climate warming. Taking winter wheat as the test crop, we investi- gated how the winter wheat growth and yields responded to the higher night temperature. In the field experiments, infrared heaters were used to increase higher night temperature (HNT) by about 2.5℃ in contrast to the normal night temperature (CK) in two whole growth durations of winter wheat in 2008-2009 and 2009-2010 in North China. The results indicated that, com- pared to the CK treatment, winter wheat yield did not decline in HNT treatment, which increased temperatures by 2.0-2.5℃ in both Wanner year (WY) and Colder year (CY). Furthermore, winter wheat yield in CY increased significantly in HNT treatment. HNT treatment in CY could significantly promote tillering and increase the effective panicles, which increased grain yield significantly (by more than 30% compared with CK). HNT treatment in CY contributed to an increase in the effective panicles and Kernels significantly, although making a significant reduction in 1000-grain weight, but did not lead to the yield decline. Under the HNT treatment, the whole growth duration of the winter wheat was shortened and the phenological dates were earlier except for the beginning of overwintering; the beginnings of the overwintering phase were postponed substantially and the ends of the overwintering phase were ahead of date compared to CK, which shortened the duration of overwintering considerably. We draw on our own studies to show examples of higher night temperature impact on winter wheat in a relative- ly cold year and relatively warm year in North China. Our results refer to winter wheat in North China, not all main winter wheat producing regions, in Huang-Huai and Southwest of China. Some uncertainties of our predictions derive from fast pro- gress in crop breeding, the variability of climate, and the role of adaptive actions in the future. As expected, the adaptation measures should be considered to cope with the impacts of global warming on crops, and further research and assessments should be conducted.展开更多
A novel satellite technique for air temperature mapping with a spatial resolution of~100 m was proposed for the town of Apatity,the Kola Peninsula(Russia),taken as a case study.The main idea behind this novel techniqu...A novel satellite technique for air temperature mapping with a spatial resolution of~100 m was proposed for the town of Apatity,the Kola Peninsula(Russia),taken as a case study.The main idea behind this novel technique is to find the statistical relationships between the land surface temperatures in each point of the study area,observed by multiple infrared thermal satellite imagery,and the time series of air temperatures recorded by World Meteorological Organization(WMO)weather station.Fourteen scenes of infrared thermal spectral band of the Landsat satellites for the period 2014–2019 were used,as well as the long-term time series of air temperature from the weather station and the results of air temperature observations carried out by the network of loggers.For calm weather conditions,according to the ground truth,the error of air temperature mapping wasσ=1.5°C,and the precision was estimated asδ=1.0°C.An analysis of the compiled air temperature map showed that,under polar night conditions,the air temperature on the hilltops was by 10–18°C higher than in the lowlands.It was concluded that,for economic reasons,as well as for the reasons of population health protection in the Arctic,it would be advisable to plan the placement of new cities on the hills.Each of these new areas should be designed in a“semi-isolated”manner in order to minimize the time needed by the local people for crossing the lowlands between the nearby districts.A characteristic feature of modern megalopolises is their internal structure formed by the growing primary settlements that can be considered as nuclei interlinked by transportation routes.Thus,the new Arctic cities can be called“Arctic megalopolises”because of their internal structure that is specific to megalopolises.展开更多
基金the financial assistance provided by ICAR-IARI in the form of IARI Fellowship and Department of Science and Technology, Innovation in Science Pursuit for Inspired Research during the PhD programme。
文摘Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22.
基金Supported by National Natural Science Foundation of China(30170640)~~
文摘[Objective] The aim was to explore the effects of low night temperature treatment on sucrose synthesis ability of tomato leaves in seedling stage.[Method] Effects of low night temperature of 6 ℃(with 15 ℃ as control)on the sucrose synthesis ability of tomato leaves were studied after 1,3,5,7 d of treatment.[Result] The contents of fructose,glucose and sucrose in tomato leaves were higher than control at 6:00 during the treatment of low night temperature,but in contrast at 11:00.The contents of fructose,glucose and sucrose in tomato leaves of low night temperature treatment and control group at 6:00 were lower than that at 11:00.The content of starch in tomato leaves was higher than control at 6:00 and 11:00 during the treatment.And the activities of sugar metabolism enzymes of tomato were changed by the treatment of low night temperature.The activities of acid invertase(AI)and neutral invertase(NI)were higher than those of control,while the activities of sucrose synthase(SS)and sucrose phosphate synthase(SPS)were lower than control at 6:00 and 11:00 during the treatment.The activity of all the enzymes at 11:00 of low night temperature treatment plants treated for 1,3,5,7 d was higher than that at 6:00.Compared to 6:00,the invertase activity of the control plant decreased,while the synthetase activity increased.The activity of sucrose synthase(SS)was decreased for treated plants,and the increase amount of sucrose content in leaves was lower than that of control at 11:00 during the treatment,indicating that the sucrose synthesis ability of tomato leaves was decreased by the treatment of low night temperature.[Conclusion] The results in this study had provided theoretical basis for the environmental control of high-yield cultivation of tomato.
基金Supported by the China Postdoctoral Science Foundation(2012M510839)Doctoral Fund of Ministry of Education of China(20122103120011)+2 种基金the National Natural Science Initial Foundation of Shenyang Agricultural University,China(20112013)the Postdoctoral Science Foundation of Shenyang Agricultural University,China(105110)the Peanut Nutrition and Fertilizer Program for China Agriculture Research System,China(CARS-14)
文摘The effects of different levels of CaCl 2 on photosynthesis under low night temperature(8°C) stress in peanuts were studied in order to find out the appropriate concentration of Ca2+through the artificial climate chamber potted culture test.The results indicated that Ca2+,by means of improving the stomatal conductivity of peanut leaves under low night temperature stress,may mitigate the decline of photosynthetic rate in the peanut leaves.The regulation with 15 mmol L-1CaCl 2(Ca15) was the most effective,compared with other treatments.Subsequently,the improvement of Ca2+on peanut photosynthesis under low night temperature stress was validated further through spraying with Ca15,Ca2+chelator(ethylene glycol bis(2-aminoethyl) tetraacetic acid; EGTA) and calmodulin antagonists(trifluonerazine; TFP).And CaM(Ca2+-modulin) played an important role in the nutritional signal transduction for Ca2+mitigating photosynthesis limitations in peanuts under low night temperature stress.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China(20070759002)the Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD21B02)
文摘Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.
文摘Temperature integration where high day temperatures are compensated by lower night temperatures is one strategy that can be used to reduce energy consumption in greenhouses. Crop tolerance to temperature variation is a prerequisite for using such a strategy. Greenhouse experiments were conducted on tomatoes cvs, Capricia, Mecano and Cederico in order to investigate the effect of different day/night temperature regimes (24/17, 27/14 and 30/11℃) where the same mean temperature was maintained for the production and germination of pollen. In addition, fruit quality as determined by fruit firmness, dry matter content, soluble solids, titratable acids, and pH was examined at harvest and after seven and 14 days of storage. The 30/11℃ treatment significantly increased pollen production and germination compared to the 24/17℃ treatment, while the 27/14℃ treatment was generally in between the other two treatments. Fruits grown at the 27/14℃ treatment were significantly firmer, while fruits grown at 24/17℃ had higher dry matter content, soluble solids, and titratable acids compared to the other treatments. There were significant differences between cultivars with respect to firmness, dry matter, titratable acidity, and pH. The quality of the fruits changed during storage, but the storability of the tomatoes was not affected by preharvest temperature treatments. The overall conclusion was that the 27/14℃ treatment was superior to the other two temperature treatments with respect to the studied parameters.
文摘The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.
文摘Heat stress studies in rice (<em>Oryza sativa</em> sp.) under extreme weather scenarios generally use constant temperatures to influence the crop responses without relation to actual weather changes. These heat stress studies may have limited implications for future crop yields because elevated temperatures are not based on local temperature fluctuations. This study investigated the night-time air temperature pattern and assessed the status and reliability of available weather station data in four major rice growing states;Arkansas (AR), California (CA), Louisiana (LA) and Texas (TX) using four public weather station databases. Hourly and daily night-time air temperatures from 20:00 to 06:00 were obtained from 1940 to 2018 during the rice growing period. During the 67-year period, a significant increase of 1.12<span style="white-space:nowrap;">°</span>C and 0.53<span style="white-space:nowrap;">°</span>C in seasonal night air temperature occurred in CA and AR (<em>P</em> ≤ 0.001) while LA and TX showed minimal to no increase in night air temperature. Across all rice states and years, night air temperature fluctuations ranged between ±0.2<span style="white-space:nowrap;">°</span>C and ±4<span style="white-space:nowrap;">°</span>C with the greatest occurred in CA (2.9<span style="white-space:nowrap;">°</span>C) and AR (4.5<span style="white-space:nowrap;">°</span>C). Mean night-time air temperature across all states ranged from 22.6<span style="white-space:nowrap;">°</span>C to 29.5<span style="white-space:nowrap;">°</span>C with a rate of increase of 0.01<span style="white-space:nowrap;">°</span>C to 0.02<span style="white-space:nowrap;">°</span>C per year since 1941. Due to a relatively smaller spatial dataset (from 1941-2018), trend analyses for AR, TX and LA showed modest bias with root mean square errors (RMSE) of 0.5<span style="white-space:nowrap;">°</span>C to 1.1<span style="white-space:nowrap;">°</span>C of absolute mean temperature across all locations. Results in this study showed seasonal night-time air temperature change occurred in some major US rice producing states during the last 67-years. This study highlights the need for more weather stations near agricultural farms to reliably derive actual temperature patterns in the rice growing regions.
文摘If low night temperatures can be combined with high day temperatures, providing optimal growth conditions for plants, a significant energy saving can be achieved in greenhouses. Lowering the night temperature from 18°C to 10°C-11°C for 8 h had no negative effect on the CO2 exchange rate (CER) during the following light period in tomato. This was found both in plants grown in artificial light only or in combination with daylight. Allowing the temperature to increase from 20°C to about 40°C, in parallel with an increasing solar photon flux density (PFD) from 0 up to about 800 μmol·m-2·s-1 in the greenhouse during summer, progressively increased CER when the CO2 concentration was maintained at 900 μmol·mol-1. At 400 μmol·mol-1 CO2, maximum CER was reached at about 600 μmol·m-2·s-1 PFD combined with a temperature of 32°C, and leveled out with a further increase in PFD and temperature. Maximum CER at high CO2 concentration was around 100% higher than at low CO2 level. Under early autumn conditions, CER increased up to about 500 μmol·m-2·s-1 PFD/32°C at low CO2 and up to about 600 μmol·m-2·s-1 PFD/35°C at high CO2. An elevated CO2 level doubled the CER in this experiment as well. Measurements of chlorophyll fluorescence showed no effect of low night temperature, high day temperature or CO2 concentration on the quantum yield of photosynthesis, indicating that no treatment negatively affected the efficiency of the photosynthetic apparatus. The results showed that low night temperatures may be combined with very high day temperatures without any loss of daily photosynthesis particularly in a CO2 enriched atmosphere. If this can be combined with normal plant development and no negative effects on the yield, significant energy savings can be achieved in greenhouses.
文摘The study aimed at analyzing the trends and variability of temperature extreme</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> over </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">northeastern highlands in Tanzania, specifically over Arusha and Kilimanjaro regions. Quality controlled mean monthly, daily maximum and minimum temperature data for the period 1961 to 2020</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> obtained from Tanzania Meteorological Authority</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> were used in the study. Rclimdex and the National Climate Monitoring Products (NMCP) software</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> developed by the World Meteorological Organization (WMO)</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> were used for computation of the indices at a monthly, seasonal and annual time scale. The computed indices were also subjected to trend analysis to determine their direction and magnitude of change. Extraction and assessment of the top five highest and lowest maximum and minimum temperature</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> also done. Increasing trends of temperature anomalies for seasonal and annual timescale</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> were observed for both Arusha and Kilimanjaro regions. Also, the increasing trends of warm and extreme warm days and nights and relatively increasing trends of cold and extreme cold days and nights were observed for both regions. The highest ever recorded temperatures since the establishment of the two stations were 36.3?C observed on 16</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> February 2011 and 38.6?C observed on 22</span><sup><span style="font-family:Verdana;">nd</span></sup><span style="font-family:Verdana;"> February 2005 for Arusha and Kilimanjaro respectively. These results indicate that The last two decades have been characterized by enhanced warming, which is consistent with overall global temperature trend patterns as depicted in recent IPCC reports and the report of the State of Climate in Africa.
文摘[ Objective] The research aimed to study temporal-spatial change characteristics of the extremely low temperature climate event in winter of China. [MethodI By using actual probability distribution threshold value method, EOF analysis method and the daily minimum temperature data in winter of 1961 -2008 at 195 observatories of China, temporal-spatial change characteristics of the extremely low temperature climate event in win- ter of China in 48 years were analyzed. [ Result] Threshold value calculated by actual probability distribution was higher than that by traditional method, and increase magnitude in east was bigger than that in west, which could describe climatic change situation in China in 48 years better than traditional method. Cold night number in winter of China did not decrease as latitude declined, and it was more in south and north and was less in Yellow River basin and northwest China. Cold night number was the most in northeast Inner Mongolia. Interannual change of the cold night number presented decline tendency. From the 1960s to the eady 1970s, cold night number consistently increased, and change in middle and late periods of the 1960s was severe. From the early 1970s to the middle 1980s, fluctuation of the cold night number was bigger, and increase of the cold night number was the most in 1976. Cold night number from 1986 to the 21= century continuously declined. Change of the cold night number was the most obvious in east region, Guizhou and north Guangxi. Cold night number in northeast China and north Inner Mongolia presented inverting change relationship with that in Yunnan - Kweichow Plateau and Hexi Corridor. [ Conclusion] The research provided reference for eady warning of the extremely low temoerature event in China.
基金supported by National Research Institutes of Basic Research and Operating Expenses of China (Grant No. 2008Y005)National Basic Research Program of China (Grant No. 2010CB951300)
文摘The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature (Tmin) has risen more than twice as fast as the daily maximum temperature (Tmax) during the 20th century. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to in- vestigate how the crops respond to the Train rise. In particular, no experiment research has reported on how crops respond to the higher night temperature, which was the main trend in the climate warming. Taking winter wheat as the test crop, we investi- gated how the winter wheat growth and yields responded to the higher night temperature. In the field experiments, infrared heaters were used to increase higher night temperature (HNT) by about 2.5℃ in contrast to the normal night temperature (CK) in two whole growth durations of winter wheat in 2008-2009 and 2009-2010 in North China. The results indicated that, com- pared to the CK treatment, winter wheat yield did not decline in HNT treatment, which increased temperatures by 2.0-2.5℃ in both Wanner year (WY) and Colder year (CY). Furthermore, winter wheat yield in CY increased significantly in HNT treatment. HNT treatment in CY could significantly promote tillering and increase the effective panicles, which increased grain yield significantly (by more than 30% compared with CK). HNT treatment in CY contributed to an increase in the effective panicles and Kernels significantly, although making a significant reduction in 1000-grain weight, but did not lead to the yield decline. Under the HNT treatment, the whole growth duration of the winter wheat was shortened and the phenological dates were earlier except for the beginning of overwintering; the beginnings of the overwintering phase were postponed substantially and the ends of the overwintering phase were ahead of date compared to CK, which shortened the duration of overwintering considerably. We draw on our own studies to show examples of higher night temperature impact on winter wheat in a relative- ly cold year and relatively warm year in North China. Our results refer to winter wheat in North China, not all main winter wheat producing regions, in Huang-Huai and Southwest of China. Some uncertainties of our predictions derive from fast pro- gress in crop breeding, the variability of climate, and the role of adaptive actions in the future. As expected, the adaptation measures should be considered to cope with the impacts of global warming on crops, and further research and assessments should be conducted.
基金supported by SRCES RAS,by the project TRAKT 2018,by Belmont Forum project SERUS,and RFBR project no.20-55-71004Pre-processing of in-situ observations in Apatity performed by Mikhail Varentsov and Pavel Konstantinov was supported by Russian Science Foundation,project no.19-05-50112Results of this research are promoted through the activities of the PanEurasian EXperiment(PEEX)programme.We are grateful to Dr.Igor Esau for insightful discussions.
文摘A novel satellite technique for air temperature mapping with a spatial resolution of~100 m was proposed for the town of Apatity,the Kola Peninsula(Russia),taken as a case study.The main idea behind this novel technique is to find the statistical relationships between the land surface temperatures in each point of the study area,observed by multiple infrared thermal satellite imagery,and the time series of air temperatures recorded by World Meteorological Organization(WMO)weather station.Fourteen scenes of infrared thermal spectral band of the Landsat satellites for the period 2014–2019 were used,as well as the long-term time series of air temperature from the weather station and the results of air temperature observations carried out by the network of loggers.For calm weather conditions,according to the ground truth,the error of air temperature mapping wasσ=1.5°C,and the precision was estimated asδ=1.0°C.An analysis of the compiled air temperature map showed that,under polar night conditions,the air temperature on the hilltops was by 10–18°C higher than in the lowlands.It was concluded that,for economic reasons,as well as for the reasons of population health protection in the Arctic,it would be advisable to plan the placement of new cities on the hills.Each of these new areas should be designed in a“semi-isolated”manner in order to minimize the time needed by the local people for crossing the lowlands between the nearby districts.A characteristic feature of modern megalopolises is their internal structure formed by the growing primary settlements that can be considered as nuclei interlinked by transportation routes.Thus,the new Arctic cities can be called“Arctic megalopolises”because of their internal structure that is specific to megalopolises.