[Objectives]To determine physicochemical characteristics and antioxidant activity of Ganoderma lucidum polysaccharides(GLP)in different growth stages and culture media.[Methods]Five polysaccharides(GLP1,GLP2,GLP3,GLPW...[Objectives]To determine physicochemical characteristics and antioxidant activity of Ganoderma lucidum polysaccharides(GLP)in different growth stages and culture media.[Methods]Five polysaccharides(GLP1,GLP2,GLP3,GLPW and GLPB)were extracted and purified from the fruiting body of G.lucidum at three growth stages and culture substrates(wood culture and bag culture).The chemical components and antioxidant activity of the five polysaccharides were determined.[Results]GLP1 contained the highest content of neutral sugar(87.65%)and GLP3 had the highest uronic acid content.All the samples mainly comprised glucose,galactose,mannose,xylose and arabose with different ratios.Moreover,their antioxidant activities were investigated on the basis of DPPH radical,ABTS radical,SOD-like activity,and antihaemolytic activity.Results indicated in all three growth stages GLP2 had the greatest antioxidant properties.In addition,the antioxidant activity of GLPW was significantly higher than that of GLPB.[Conclusions]Overall,by comparison,G.lucidum in growth stage two may have potential health benefits,and wood culture may be a superior choice of artificial cultivation due to their abundance of active polysaccharides.展开更多
Jincheng orange(Citrus sinensis Osbeck)is widely grown in Chongqing,China,and is commonly consumed because of its characteristic aroma contributed by the presence of diverse volatile compounds.The changes in aroma dur...Jincheng orange(Citrus sinensis Osbeck)is widely grown in Chongqing,China,and is commonly consumed because of its characteristic aroma contributed by the presence of diverse volatile compounds.The changes in aroma during the development and maturation of fruit are indicators for ripening and harvest time.However,the influence of growth stages on the volatile compounds in Jincheng orange remains unclear.In addition,volatiles originate from fatty acids,most of which are the precursors of volatile substances.On this basis,gas chromatography-mass spectrometry(GC-MS)was performed to elaborate the changes in volatile constituents and fatty acids as precursors.This study tested proximately 60 volatiles and 8 fatty acids at 9 growth and development stages(AF1-AF9).Of those compounds,more than 92.00%of total volatiles and 87.50%of fatty acids were terpenoid and saturated fatty acids,respectively.As shown in the PCA plot,the AF5,AF6,and AF9 stages were confirmed as completely segregated and appeared different.In addition,most of the volatiles and fatty acids first increased at the beginning of the development stage,then decreased from the AF6 development stage,and finally increased at the AF9 maturity stage.Moreover,the highest contents of terpenoid,alcohols,aldehydes,ketones,and saturated fatty acids in Jincheng orange peel oil were d-limonene,linalool,octanal,cyclohexanone,and stearic acid during development stages,respectively.Our results found that the growth stages significantly affected the volatile constituents and precursors in Jincheng orange peel oil.展开更多
[Objective] The aim was to study the effects of short-term high temperature stress on the photosynthesis of potato in different growth stages. [Method] Choosing powder potato named Longshu No.3 widely cultivated in Ni...[Objective] The aim was to study the effects of short-term high temperature stress on the photosynthesis of potato in different growth stages. [Method] Choosing powder potato named Longshu No.3 widely cultivated in Ningxia as test material,the changes of stomata conductance (Gs),transpiration rate (Tr) and CO2 concentration difference between internal and external leaf chamber,net photosynthetic rate (Pn) and photosynthetic water use efficiency (WUE) in different growth stages under short-term high temperature were analyzed. [Result] During seedling stage,the hysteretic nature of net photosynthetic rate and CO2 concentration difference between internal and external leaf chamber of potato could be found under high temperature stress,while the change trends of stomata conductance and transpiration rate under high temperature stress were consistent to that at normal temperature,but stomata conductance and transpiration rate were higher than those at normal temperature,and CO2 concentration difference between internal and external leaf chamber affected net photosynthetic rate most obviously. During branching stage,the change trends of net photosynthetic rate,CO2 concentration difference between internal and external leaf chamber,stomata conductance and transpiration rate under high temperature stress and normal temperature were similar,but they changed abruptly and reached peak value at noon under high temperature stress,while there existed consistent variation of water use efficiency under high temperature stress and at normal temperature,and CO2 concentration difference between internal and external leaf chamber also affected net photosynthetic rate most greatly,next came transpiration rate. [Conclusion] High temperature stress affected the photosynthesis of potato in different growth stages,and it was more obvious during branching stage than seedling stage,while CO2 concentration difference between internal and external leaf chamber had the most important influence on net photosynthetic rate.展开更多
[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen (N) uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was con...[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen (N) uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was conducted to investigate the effects of wateriogging through comparing WL1 (waterlogging at peak squaring stage) and WL2 (waterlogging at flowering and boll-forming stage) treatments with their controls respectively. [Result] The results showed that the effect of WL1 on N uptake of cotton root was stronger than WL2. At 20 days (d) after WL1 treatment, the root biomass (RB), N uptake (NU), and N uptake rate (NUR) significantly decreased by 38.1%, 48.6%, and 53.0% respectively. At 20 d after WL2 treatment, the RB, NU, and NUR significantly decreased by 27.3%, 46.0%, and 44.8% respectively. More N was distributed to root and leaf after WL1 treatment, and to square, flower, and boll after WL2 treatment. N physiological use efficiency increased by 11.4% and 44.4% after WL1 and WL2 treatments respectively. Further analysis showed that the effects of WL1 on yield and its components of cotton were stronger than WL2. The boll number, boll weight, and lint yield per plant significantly reduced by 40.5%, 12.4%, and 49.5% after WL1 treatment, and significantly decreased by 23.1%, 6.9%, and 29.9% after WL2 treatment, respectively. [Conclusion] The negative effects of water- logging at peak squaring stage on N nutrition and yield of cotton were stronger than waterlogging at flowering and boll-forming stage, indicating that more attention should be paid to waterlogging at peak squaring stage and sound N management can improve cotton regrowth and reduce yield loss after waterlogging.展开更多
[Objective] This study aimed to investigate the nutritional characteristics of Dianjiang peony at different growth stages.[Method] The yield,nutrient content and nutrient uptake of Dianjiang peony at different growth ...[Objective] This study aimed to investigate the nutritional characteristics of Dianjiang peony at different growth stages.[Method] The yield,nutrient content and nutrient uptake of Dianjiang peony at different growth stages and available nutrient content in soil were investigated by field survey and indoor chemical analysis.[Resuit] The results showed that biomass,leaf weight,tender stem weight and cortex moutan weight (yield) of 1-4 years old peony exhibited a significant quadratic regression relationship with the cultivation duration.The average content and uptake of 12 nutrients in leaves exhibited an overall order of Ca>N>K>Mg>S>P>Fe>Mn> Zn>Cu,which was consistent to that in tender stems.However,the average content and uptake of various nutrient elements in cortex moutan exhibited an overall order of N>Ca>K>Mg>P>S>Fe>Zn>Cu>Mn,which was different from that in leaves and tender stems.In addition,the average content and uptake of various nutrient elements in petioles exhibited an overall order of Ca>K>N>Mg>S>P>Fe>Mn>Zn>Cu.The content of organic matter in soil of Dianjiang peony at different growth stages varied greatly; to be specific,contents of N,S,Mn and Zn were higher.[Conclusion] This study provided theoretical basis for the production of high-quality and high-yield peony.展开更多
The effect of nitrate (NO3^-) on rice (Oryza sativa L.) growth as well as N absorption and assimilation during different growth stages was examined using three typical rice cultivars. Dry weight, yield, N uptake, ...The effect of nitrate (NO3^-) on rice (Oryza sativa L.) growth as well as N absorption and assimilation during different growth stages was examined using three typical rice cultivars. Dry weight, yield, N uptake, nitrate reductase activity (NRA) in leaves, and glutamine synthetase activity (GSA) in roots and leaves during their entire growth periods, as well as the kinetic parameters of ammonium (NH4^+) uptake at the seedling stage, were measured with solution culture experiments. Results indicated that addition of NH4^+-N and NO3^-N at a ratio of 75:25 (NH4^++NO3^- treatment) when compared with that of NH4^+-N alone (NH4^+ treatment) increased the dry weight of ‘Nanguang' cultivar by 30% and ‘Yunjing 38' cultivar by 31%, and also increased their grain yield by 21% and 17%, respectively. For the four growth stages, the total N accumulation in plants increased by an average of 36% for ‘Nanguang' and 31% for ‘Yunjing 38', whereas the increasing effect of NO3^- in the ‘4007' cultivar was only found at the seedling stage, in the NH4^++NO3^- treatment compared to the NH4^+ treatment, NRA in the leaves increased by 2.09 folds, and GSA increased by 92% in the roots and 52% in the leaves of the three cultivars. NO3^- supply increased the maximum uptake rate (Vmax) in the ‘Nanguang' and ‘Yunjing 38' cultivars, reflecting that the NO3^- itself, not the increasing N concentration, increased the uptake rate of NH4^+ by rice. There was no effect on the apparent Michaelis-Menten constant (Kin) of the three cultivars. Thus, some replacement of NH4^+ with NO3^-could greatly improve the growth of rice plants, mainly on account of the increased uptake of NH4^+ promoted by NO3^-, and future studies should focus on the molecular mechanism of the increased uptake of NH4^+ by NO3^-.展开更多
The vertical migration of Aphelenchoides besseyi under different temperatures and humidities and at different rice growth stages was investigated. It was found that the optimum temperature for the development and repr...The vertical migration of Aphelenchoides besseyi under different temperatures and humidities and at different rice growth stages was investigated. It was found that the optimum temperature for the development and reproduction of A. besseyiwas 25-30℃. At the same temperature, the rate of vertical migration increased with rising relative humidity. Artificial inoculation tests showed that at the elongation stage, nematodes survived mainly on the upper and middle parts of rice culms and the number of nematodes decreased by 50% at 20 days after inoculation compared with that at 5 days after inoculation. Whereas at the booting stage, nematodes accumulated in young panicles and reproduced quickly,, and the average number of nematodes at 20 days after inoculation increased to 164.5, three times of that at 5 days after inoculation.展开更多
Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a...Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on comparing plants with different rates of growth.Whether N fertilization could accelerate rates of growth and maturation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape positions.The plots were located under conditions where preplant N fertilization reduced or avoided temporary N shortages for some plants but did not reduce for other plants early in the season.We measured corn heights to the youngest leaf collar,stages of growth and chlorophyll meter readings (CMRs). The added N advanced growth stages as well as increased corn heights and CMRs at any given time.Fertilization effects on corn heights,growth stages and ear weights were statistically significant (P<0.05) despite substantial variability associated with landscape.Reductions in growth due to a temporary shortage of N within a growth stage might be partially offset by longer periods of growth within that stage to physiological maturity.Temporary shortages of N,therefore,may produce symptoms of N deficiency in situations where subsequent additions of N should not be expected to increase yields.Recognition of these two somewhat different effects (i.e.,increase growth rates and advance growth stages) on corn growth could help to define N deficiency more precisely and to improve the accuracy of diagnosing N status in production agriculture.展开更多
Maize(Zea mays L.) can exhibit yield penalties as a result of unfavorable changes to growing conditions. The main threat to current and future global maize production is heat stress. Maize may suffer from heat stress ...Maize(Zea mays L.) can exhibit yield penalties as a result of unfavorable changes to growing conditions. The main threat to current and future global maize production is heat stress. Maize may suffer from heat stress in all of the growth stages, either continuously or separately. In order to manage the impact of climate driven heat stress on the different growth stages of maize, there is an urgent need to understand the similarities and differences in how heat stress affects maize growth and yield in the different growth stages. For the purposes of this review, the maize growth cycle was divided into seven growth stages, namely the germination and seedling stage, early ear expansion stage, late vegetative growth stage before flowering, flowering stage, lag phase, effective grain-filling stage, and late grain-filling stage. The main focus of this review is on the yield penalty and the potential physiological changes caused by heat stress in these seven different stages. The commonalities and differences in heat stress related impacts on various physiological processes in the different growth stages are also compared and discussed. Finally, a framework is proposed to describe the main influences on yield components in different stages, which can serve as a useful guide for identifying management interventions to mitigate heat stress related declines in maize yield.展开更多
Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on aband...Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on abandoned farmland. However, few studies have investigated runoff and soil loss from sloping farmland during crop growth season. The objective of this study was to investigate the effects of soil management on runoff and soil loss on sloping farmland during crop growth season. We tested different soybean growth stages (i.e., seedling stage (R1), initial blossoming stage (R2), full flowering stage (R3), pod bearing stage (R4), and initial filling stage (R5)) and soil management practice (one plot applied hoeing tillage (HT) before each rainfall event, whereas the other received no treatment (NH)) by applying simulated rainfall at an intensity of 80 mm/h. Results showed that runoff and soil loss both decreased and infiltration amount increased in successive soybean growth stages under both treatments. Compared with NH plot, there was less runoff and higher infiltration amount from HT plot. However, soil loss from HT plot was larger than that from NH plot in R1–R3, but lower in R4 and R5. In the early growth stages, hoeing tillage was effective for reducing runoff and enhancing rainfall infiltration. By contrast, hoeing tillage enhanced soil and water conservation during the late growth stages. The total soil loss from HT plot (509.0 g/m2) was 11.1% higher than that from NH plot (457.9 g/m2) in R1–R5. However, the infiltration amount from HT plot (313.9 mm) was 18.4% higher than that from NH plot (265.0 mm) and the total runoff volume from HT plot was 49.7% less than that from NH plot. These results indicated that crop vegetation can also act as a type of vegetation cover and play an important role on sloping farmland. Thus, adopting rational soil management in crop planting on sloping farmland can effectively reduce runoff and soil loss, as well as maximize rainwater infiltration during crop growth period.展开更多
Morphological and chemical studies on zircon grains from gabbro and granite of the Pingtan magmatic complex, Fujian Province, eastern China, show that there are three stages of zircon growth. The early stage of zircon...Morphological and chemical studies on zircon grains from gabbro and granite of the Pingtan magmatic complex, Fujian Province, eastern China, show that there are three stages of zircon growth. The early stage of zircon growth is characterized by colorlessness, high transparence and birefringence, low and dispersive Ipr and Ipy, weak and homogeneous BSE brightness, lower Hf content and depletion of U, Th and Y; the middle stage is characterized by abruptly increasing lpy, progressively strong and sectoral-zoning BSE brightness, higher Hf content and enrichment of U, Th and Y with Th/U 〉 1; the late stage of growth is characterized by brownish color, poor transparence, low birefringence, highest Ipr and Ipy, middle and oscillatorily-zoning BSE brightness, highest contents of Hf, U and Y with Th/U 〈 1. The stages are considered to be formed in a deep magma chamber, ascent passage and emplacement site, respectively. Due to the more or less long residual time of the magma chamber, the difference in age between the early and late stages of zircon might be great enough to be distinguished, which can be attributed to tectonic constraint for the magnlatism.展开更多
Understanding the characteristics of rice productivity is of great importance for achieving high yield formation.However,such traits have not yet been studied for different ages of hydroponically grown long-mat rice s...Understanding the characteristics of rice productivity is of great importance for achieving high yield formation.However,such traits have not yet been studied for different ages of hydroponically grown long-mat rice seedlings(HLMS),which constitutes a new method of seedling cultivation.Field experiments were conducted to evaluate the effects of seedling age on the growth stage,photosynthesis characteristics,dry matter production,and yield of HLMS.A conventional japonica rice cultivar(Wuyunjing 24)and an indica hybrid rice cultivar(6 Liangyou 9368)were used as test materials.The results showed that the whole phase was shortened by 13-15 days for young seedlings(13-day-old)compared with old seedlings(27-day-old),which occurred because the growth process accelerated with the transplantation of young seedlings.As seedling age increased,the dry matter weight of stems of individual plants and of the population increased at the transplanting stage but decreased at the maturity stage(MS).Compared with that of 27-day-old seedlings,the average ratio of panicle weight to total plant dry weight of 13-day-old seedlings during a 2-year period increased by 3.71%for Wuyunjing 24 and by 3.78%for 6 Liangyou 9368 at the MS.Moreover,as seedling age increased,the leaf area index and photosynthetic potential decreased for both cultivars,and the photosynthetic rate markedly decreased at the heading stage(HS).With the exception of that of Wuyunjing 24 from the jointing stage to the HS in 2014,the crop growth rate was higher for young seedlings than for old seedlings.Grain yield significantly decreased with seedling age,but no significant difference was detected between the 13-and 20-day-old seedlings for either cultivar.Therefore,equilibrious and high biological yield formation,vigorous growth in the late stages,and high photosynthetic production capacity are important characteristics and causes of the efficient and sustainable output of photosynthetic systems and for achieving high yield formation in young transplanted seedlings(13-20-day-old).展开更多
Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy str...Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy structure across different growth stages has great impacts on wheat LCC estimation, known as growth stage effects. It will result in the heterogeneity of crop canopy at different growth stages, which would mask subtle spectral response of biochemistry variations. This study aims to explore spectral responses on the growth stage effects and establish LCC models suited for different growth stages. A total number of 864 pairwise samples of wheat canopy spectra and LCC values with 216 observations of each stage were sampled at the tillering, jointing, booting and heading stages in 2021. Firstly, statistical analysis of LCC and spectral response presented different distribution traits and typical spectral variations peak at 470, 520 and 680 nm. Correlation analysis between LCC and reflectance showed typical red edge shifts. Secondly, the testing model of partial least square(PLS) established by the entire datasets to validate the predictive performance at each stage yielded poor LCC estimation accuracy. The spectral wavelengths of red edge(RE) and blue edge(BE) shifts and the poor estimation capability motivated us to further explore the growth stage effects by establishing LCC models at respective growth periods.Finally, competitive adaptive reweighted sampling PLS(CARS-PLS), decision tree(DT) and random forest(RF) were used to select sensitive bands and establish LCC models at specific stages. Bayes optimisation was used to tune the hyperparameters of DT and RF regression. The modelling results indicated that CARS-PLS and DT did not extract specific wavelengths that could decrease the influences of growth stage effects. From the RF out-of-bag(OOB) evaluation, the sensitive wavelengths displayed consistent spectral shifts from BE to GP and from RE to RV from tillering to heading stages. Compared with CARS-PLS and DT,results of RF modelling yielded an estimation accuracy with deviation to performance(RPD) of 2.11, 2.02,3.21 and 3.02, which can accommodate the growth stage effects. Thus, this study explores spectral response on growth stage effects and provides models for chlorophyll content estimation to satisfy the requirement of high-throughput phenotyping.展开更多
The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on th...The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.展开更多
In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were sim...In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were simulated by using the regional climate model PRECIS.And then put the meteorological data into the crop model to simulate the growth of wheat under climate change conditions in the future.The results showed that there would be a trend of rising temperature and increasing precipitation in Weifang in the future.Climate warming would result in growth period of wheat to be ahead of schedule and yield reduction.If taking into account the effect of CO2,the yield of wheat would increase.展开更多
The dynamics of sap flow in relation to plant morphology and weather conditions during reproductive growth of soybean (Glycine max. L. Merr.) influence decisions pertaining to efficient irrigation management and other...The dynamics of sap flow in relation to plant morphology and weather conditions during reproductive growth of soybean (Glycine max. L. Merr.) influence decisions pertaining to efficient irrigation management and other inputs for high yields. Field studies began in 2017 at Marianna, Arkansas to measure moisture dynamics of soybeans during seed fill (R5 to R7) using heat balance stem flow gauges. Sap flow was highly correlated to solar radiation with maximum rates observed during beginning seed fill (R5). A solar radiation efficiency (SRE) value, calculated as hourly sap flow rate per Watt-hour of solar radiation (g/Wh2), is proposed. The SRE relates to crop water demand and hydraulic resistance of the soil-root-stem-leaf-pod-seed pathway. SRE values ranged from 0 - 1.2 g/Wh2. Soil moisture, growth stage, time of day, and weather conditions influenced the SRE, with higher values observed in the morning, late afternoon, and during R5 growth. Peak sap flows of 39 g/h at R5, 25 g/h at R6, and 3 g/h at R7 occurred. The ratio of measured sap flow to estimated crop evapotranspiration was 0.9 to 1.3 during R5 to R6.9 (maximum dry matter), but dropped to 0.2 at R7. Further research is needed to better understand late season reproductive moisture dynamics in soybeans.展开更多
The pathogen of tomato powdery mildew (Oidium neolycopersici Kiss) was simultaneously inoculated into four varieties during seedling, flowering and fruiting stages under the same environmental conditions by inducing...The pathogen of tomato powdery mildew (Oidium neolycopersici Kiss) was simultaneously inoculated into four varieties during seedling, flowering and fruiting stages under the same environmental conditions by inducing inoculation method, so as to study the resistance during different growth stages. Different varieties of plants and the plants during different growth stages were investigated after inoculation for 12 d, and disease epidemic curves were drawn according to survey data. The results showed that different varieties performed different resistance against powdery mildew and the same variety also showed different resistance during different growth stages. The susceptible extent of Lujia was the heaviest during seedling and flowering sages, while it showed the strongest resistance during fruiting stage; improved 96 -8 showed the highest resistance during seedling stage, but performed the lowest resistance during fruiting stage.展开更多
Background:Tan sheep,an important local sheep breed in China,is famous for their fur quality.One-month-old Tan sheep have white,curly hair with beautiful flower spikes,commonly known as“nine bends”,which has high ec...Background:Tan sheep,an important local sheep breed in China,is famous for their fur quality.One-month-old Tan sheep have white,curly hair with beautiful flower spikes,commonly known as“nine bends”,which has high economic value.However,the“nine bends”characteristic gradually disappears with age;consequently,the economic value of the Tan sheep decreases.Age-related changes in DNA methylation have been reported and may be responsible for age-induced changes in gene expression.Until now,no genome-wide surveys have been conducted to identify potential DNA methylation sites involved in different sheep growth stages.In this study we investigated the dynamic changes of genome-wide DNA methylation profiles in Tan sheep using DNA from skin and deep whole-genome bisulfite sequencing,and compared the DNA methylation levels at three different growth stages:1,24,and 48 months old(mon1,mon24,and mon48,respectively).Results:In this study,11 skin samples from three growth stages(four for mon1,four for mon24,and three for mon48)were used for DNA methylation analysis and gene expression profiling.There were 52,288 and 236 differentially methylated genes(DMGs)identified between mon1 and mon24,mon1 and mon48,and mon24 and mon48,respectively.Of the differentially methylated regions,1.11%,7.61%,and 7.65% were in the promoter in mon1 vs.mon24,mon24 vs.mon48,and mon1 vs.mon48,respectively.DMGs were enriched in the MAPK and WNT signaling pathways,which are related to age growth and hair follicle morphogenesis processes.There were 51 DMGs associated with age growth and curly fleece formation.Four DMGs between mon1 and mon48(KRT71,CD44,ROR2 and ZDHHC13)were further validated by bisulfite sequencing.Conclusions:This study revealed dynamic changes in the genomic methylation profiles of mon1,mon24,and mon48 sheep,and the percentages of methylated cytosines were 3.38%,2.85% and 4.17%,respectively.Of the DMGs,KRT71 and CD44 were highly methylated in mon1,and ROR2 and ZDHHC13 were highly methylated in mon48.These findings provide foundational information that may be used to develop strategies for potentially retaining the lamb fur and thus improving the economic value of Tan sheep.展开更多
The initial stage of Ag film growth on Cu(100). Ta(100) and Ta(110) single crystals as well as YBaCuO on Si single crystal covered by Pd was investigated in situ by means of LAS 600 surface analysis system with a sput...The initial stage of Ag film growth on Cu(100). Ta(100) and Ta(110) single crystals as well as YBaCuO on Si single crystal covered by Pd was investigated in situ by means of LAS 600 surface analysis system with a sputtering source in sample preparation chamber. The results show that the initial state for Ag / Cu(100) film growth is typical S-K model, for Ag / Ta(100) and Ag / Ta(110)they have the same S-K characteristics, but due to the different surface energies of two crystalline planes. there is some difference for Ag / Ta (100) and Ag / Ta(110). YBCO sputterjng process is rather complex and Cu is the first element appearing in the film.展开更多
The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi ...The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi Special Zone of Guizhou Province in 2021 and combining with the meteorological data of temperature and precipitation in the base in the same period.The results showed that Hongyang,Donghong and Jinhong all sprouted on February 1,and had the same response to temperature and precipitation.From germination to leaf spreading stage,Hongyang and Donghong had the same response to precipitation,while Donghong and Jinhong had the same response to temperature,but Jinhong needed 32.5 mm precipitation to meet its growth and development.From leaf spreading stage to budding stage,Hongyang and Donghong had similar responses to temperature and precipitation,while Jinhong needed average daily temperature of 16.5℃and precipitation of 2.1 mm.The responses of the three varieties from budding to flowering to temperature and precipitation were consistent.From flowering to fruiting,Hongyang needed 19.9℃temperature and the least precipitation,while Jinhong needed the lowest temperature and the maximum precipitation.Donghong's response to temperature and precipitation was between Hongyang and Jinhong.During the period from fruit setting to fruit ripening and picking,Hongyang needed the least temperature and precipitation,while Donghong and Jinhong had the same response to temperature and precipitation.In the key period of fruit expansion of the three kiwifruit varieties in 2021,temperature and precipitation were the most suitable for fruit expansion.In short,red cartridge kiwifruit has a good response to temperature and precipitation in different growth stages,and it requires 201 d for Hongyang variety from germination to maturity and picking,211 d for Donghong variety and 218 d for Jinhong variety.展开更多
基金Supported by the New Variety Breeding Project of Science Technology Department of Zhejiang Province(2021C02073)Agriculture,Rural Areas and Farmers and Nine-Party Project of Zhejiang Province(2022SNJF047)。
文摘[Objectives]To determine physicochemical characteristics and antioxidant activity of Ganoderma lucidum polysaccharides(GLP)in different growth stages and culture media.[Methods]Five polysaccharides(GLP1,GLP2,GLP3,GLPW and GLPB)were extracted and purified from the fruiting body of G.lucidum at three growth stages and culture substrates(wood culture and bag culture).The chemical components and antioxidant activity of the five polysaccharides were determined.[Results]GLP1 contained the highest content of neutral sugar(87.65%)and GLP3 had the highest uronic acid content.All the samples mainly comprised glucose,galactose,mannose,xylose and arabose with different ratios.Moreover,their antioxidant activities were investigated on the basis of DPPH radical,ABTS radical,SOD-like activity,and antihaemolytic activity.Results indicated in all three growth stages GLP2 had the greatest antioxidant properties.In addition,the antioxidant activity of GLPW was significantly higher than that of GLPB.[Conclusions]Overall,by comparison,G.lucidum in growth stage two may have potential health benefits,and wood culture may be a superior choice of artificial cultivation due to their abundance of active polysaccharides.
基金supported by the Guizhou Provincial Science and Technology Projects,China(ZK[2022]391)the Cultivation Project of National Natural Science Foundation of Guizhou Medical University,China(21NSFCP20).
文摘Jincheng orange(Citrus sinensis Osbeck)is widely grown in Chongqing,China,and is commonly consumed because of its characteristic aroma contributed by the presence of diverse volatile compounds.The changes in aroma during the development and maturation of fruit are indicators for ripening and harvest time.However,the influence of growth stages on the volatile compounds in Jincheng orange remains unclear.In addition,volatiles originate from fatty acids,most of which are the precursors of volatile substances.On this basis,gas chromatography-mass spectrometry(GC-MS)was performed to elaborate the changes in volatile constituents and fatty acids as precursors.This study tested proximately 60 volatiles and 8 fatty acids at 9 growth and development stages(AF1-AF9).Of those compounds,more than 92.00%of total volatiles and 87.50%of fatty acids were terpenoid and saturated fatty acids,respectively.As shown in the PCA plot,the AF5,AF6,and AF9 stages were confirmed as completely segregated and appeared different.In addition,most of the volatiles and fatty acids first increased at the beginning of the development stage,then decreased from the AF6 development stage,and finally increased at the AF9 maturity stage.Moreover,the highest contents of terpenoid,alcohols,aldehydes,ketones,and saturated fatty acids in Jincheng orange peel oil were d-limonene,linalool,octanal,cyclohexanone,and stearic acid during development stages,respectively.Our results found that the growth stages significantly affected the volatile constituents and precursors in Jincheng orange peel oil.
基金Supported by National Natural Science Foundation of China(40765003)National Key Technology R &D Program in the 11th Five Year Plan of China (2007BAC03A02)~~
文摘[Objective] The aim was to study the effects of short-term high temperature stress on the photosynthesis of potato in different growth stages. [Method] Choosing powder potato named Longshu No.3 widely cultivated in Ningxia as test material,the changes of stomata conductance (Gs),transpiration rate (Tr) and CO2 concentration difference between internal and external leaf chamber,net photosynthetic rate (Pn) and photosynthetic water use efficiency (WUE) in different growth stages under short-term high temperature were analyzed. [Result] During seedling stage,the hysteretic nature of net photosynthetic rate and CO2 concentration difference between internal and external leaf chamber of potato could be found under high temperature stress,while the change trends of stomata conductance and transpiration rate under high temperature stress were consistent to that at normal temperature,but stomata conductance and transpiration rate were higher than those at normal temperature,and CO2 concentration difference between internal and external leaf chamber affected net photosynthetic rate most obviously. During branching stage,the change trends of net photosynthetic rate,CO2 concentration difference between internal and external leaf chamber,stomata conductance and transpiration rate under high temperature stress and normal temperature were similar,but they changed abruptly and reached peak value at noon under high temperature stress,while there existed consistent variation of water use efficiency under high temperature stress and at normal temperature,and CO2 concentration difference between internal and external leaf chamber also affected net photosynthetic rate most greatly,next came transpiration rate. [Conclusion] High temperature stress affected the photosynthesis of potato in different growth stages,and it was more obvious during branching stage than seedling stage,while CO2 concentration difference between internal and external leaf chamber had the most important influence on net photosynthetic rate.
基金Supported by Jiangsu Agricultural Science and Technology Independent-innovation Fund Project(SCX(13)5071)National Natural Science Foundation of China(30900877)~~
文摘[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen (N) uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was conducted to investigate the effects of wateriogging through comparing WL1 (waterlogging at peak squaring stage) and WL2 (waterlogging at flowering and boll-forming stage) treatments with their controls respectively. [Result] The results showed that the effect of WL1 on N uptake of cotton root was stronger than WL2. At 20 days (d) after WL1 treatment, the root biomass (RB), N uptake (NU), and N uptake rate (NUR) significantly decreased by 38.1%, 48.6%, and 53.0% respectively. At 20 d after WL2 treatment, the RB, NU, and NUR significantly decreased by 27.3%, 46.0%, and 44.8% respectively. More N was distributed to root and leaf after WL1 treatment, and to square, flower, and boll after WL2 treatment. N physiological use efficiency increased by 11.4% and 44.4% after WL1 and WL2 treatments respectively. Further analysis showed that the effects of WL1 on yield and its components of cotton were stronger than WL2. The boll number, boll weight, and lint yield per plant significantly reduced by 40.5%, 12.4%, and 49.5% after WL1 treatment, and significantly decreased by 23.1%, 6.9%, and 29.9% after WL2 treatment, respectively. [Conclusion] The negative effects of water- logging at peak squaring stage on N nutrition and yield of cotton were stronger than waterlogging at flowering and boll-forming stage, indicating that more attention should be paid to waterlogging at peak squaring stage and sound N management can improve cotton regrowth and reduce yield loss after waterlogging.
基金Supported by Scientific and Technological Project of Chongqing Municipality (CSTC,2011AC1192)Project of Chongqing University of Arts and Sciences(Y2012LX43)~~
文摘[Objective] This study aimed to investigate the nutritional characteristics of Dianjiang peony at different growth stages.[Method] The yield,nutrient content and nutrient uptake of Dianjiang peony at different growth stages and available nutrient content in soil were investigated by field survey and indoor chemical analysis.[Resuit] The results showed that biomass,leaf weight,tender stem weight and cortex moutan weight (yield) of 1-4 years old peony exhibited a significant quadratic regression relationship with the cultivation duration.The average content and uptake of 12 nutrients in leaves exhibited an overall order of Ca>N>K>Mg>S>P>Fe>Mn> Zn>Cu,which was consistent to that in tender stems.However,the average content and uptake of various nutrient elements in cortex moutan exhibited an overall order of N>Ca>K>Mg>P>S>Fe>Zn>Cu>Mn,which was different from that in leaves and tender stems.In addition,the average content and uptake of various nutrient elements in petioles exhibited an overall order of Ca>K>N>Mg>S>P>Fe>Mn>Zn>Cu.The content of organic matter in soil of Dianjiang peony at different growth stages varied greatly; to be specific,contents of N,S,Mn and Zn were higher.[Conclusion] This study provided theoretical basis for the production of high-quality and high-yield peony.
基金Project supported by the National Natural Science Foundation of China (Nos. 30390082 and 40471074)
文摘The effect of nitrate (NO3^-) on rice (Oryza sativa L.) growth as well as N absorption and assimilation during different growth stages was examined using three typical rice cultivars. Dry weight, yield, N uptake, nitrate reductase activity (NRA) in leaves, and glutamine synthetase activity (GSA) in roots and leaves during their entire growth periods, as well as the kinetic parameters of ammonium (NH4^+) uptake at the seedling stage, were measured with solution culture experiments. Results indicated that addition of NH4^+-N and NO3^-N at a ratio of 75:25 (NH4^++NO3^- treatment) when compared with that of NH4^+-N alone (NH4^+ treatment) increased the dry weight of ‘Nanguang' cultivar by 30% and ‘Yunjing 38' cultivar by 31%, and also increased their grain yield by 21% and 17%, respectively. For the four growth stages, the total N accumulation in plants increased by an average of 36% for ‘Nanguang' and 31% for ‘Yunjing 38', whereas the increasing effect of NO3^- in the ‘4007' cultivar was only found at the seedling stage, in the NH4^++NO3^- treatment compared to the NH4^+ treatment, NRA in the leaves increased by 2.09 folds, and GSA increased by 92% in the roots and 52% in the leaves of the three cultivars. NO3^- supply increased the maximum uptake rate (Vmax) in the ‘Nanguang' and ‘Yunjing 38' cultivars, reflecting that the NO3^- itself, not the increasing N concentration, increased the uptake rate of NH4^+ by rice. There was no effect on the apparent Michaelis-Menten constant (Kin) of the three cultivars. Thus, some replacement of NH4^+ with NO3^-could greatly improve the growth of rice plants, mainly on account of the increased uptake of NH4^+ promoted by NO3^-, and future studies should focus on the molecular mechanism of the increased uptake of NH4^+ by NO3^-.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2001AA249021)
文摘The vertical migration of Aphelenchoides besseyi under different temperatures and humidities and at different rice growth stages was investigated. It was found that the optimum temperature for the development and reproduction of A. besseyiwas 25-30℃. At the same temperature, the rate of vertical migration increased with rising relative humidity. Artificial inoculation tests showed that at the elongation stage, nematodes survived mainly on the upper and middle parts of rice culms and the number of nematodes decreased by 50% at 20 days after inoculation compared with that at 5 days after inoculation. Whereas at the booting stage, nematodes accumulated in young panicles and reproduced quickly,, and the average number of nematodes at 20 days after inoculation increased to 164.5, three times of that at 5 days after inoculation.
基金Project supported by the Iowa Soybean Association,USA through the ISA On-Farm Network~(TM)
文摘Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on comparing plants with different rates of growth.Whether N fertilization could accelerate rates of growth and maturation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape positions.The plots were located under conditions where preplant N fertilization reduced or avoided temporary N shortages for some plants but did not reduce for other plants early in the season.We measured corn heights to the youngest leaf collar,stages of growth and chlorophyll meter readings (CMRs). The added N advanced growth stages as well as increased corn heights and CMRs at any given time.Fertilization effects on corn heights,growth stages and ear weights were statistically significant (P<0.05) despite substantial variability associated with landscape.Reductions in growth due to a temporary shortage of N within a growth stage might be partially offset by longer periods of growth within that stage to physiological maturity.Temporary shortages of N,therefore,may produce symptoms of N deficiency in situations where subsequent additions of N should not be expected to increase yields.Recognition of these two somewhat different effects (i.e.,increase growth rates and advance growth stages) on corn growth could help to define N deficiency more precisely and to improve the accuracy of diagnosing N status in production agriculture.
基金financially supported by the National Natural Science Foundation of China(32071978)the Open Project of State Key Laboratory of Crop Biology,Shandong Agricultural University,China(2021KF10)the National Key R&D Program of China(2016YFD0300203)。
文摘Maize(Zea mays L.) can exhibit yield penalties as a result of unfavorable changes to growing conditions. The main threat to current and future global maize production is heat stress. Maize may suffer from heat stress in all of the growth stages, either continuously or separately. In order to manage the impact of climate driven heat stress on the different growth stages of maize, there is an urgent need to understand the similarities and differences in how heat stress affects maize growth and yield in the different growth stages. For the purposes of this review, the maize growth cycle was divided into seven growth stages, namely the germination and seedling stage, early ear expansion stage, late vegetative growth stage before flowering, flowering stage, lag phase, effective grain-filling stage, and late grain-filling stage. The main focus of this review is on the yield penalty and the potential physiological changes caused by heat stress in these seven different stages. The commonalities and differences in heat stress related impacts on various physiological processes in the different growth stages are also compared and discussed. Finally, a framework is proposed to describe the main influences on yield components in different stages, which can serve as a useful guide for identifying management interventions to mitigate heat stress related declines in maize yield.
基金financially supported by the National Natural Science Foundation of China (41390464, 41571130083, 41271288)
文摘Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on abandoned farmland. However, few studies have investigated runoff and soil loss from sloping farmland during crop growth season. The objective of this study was to investigate the effects of soil management on runoff and soil loss on sloping farmland during crop growth season. We tested different soybean growth stages (i.e., seedling stage (R1), initial blossoming stage (R2), full flowering stage (R3), pod bearing stage (R4), and initial filling stage (R5)) and soil management practice (one plot applied hoeing tillage (HT) before each rainfall event, whereas the other received no treatment (NH)) by applying simulated rainfall at an intensity of 80 mm/h. Results showed that runoff and soil loss both decreased and infiltration amount increased in successive soybean growth stages under both treatments. Compared with NH plot, there was less runoff and higher infiltration amount from HT plot. However, soil loss from HT plot was larger than that from NH plot in R1–R3, but lower in R4 and R5. In the early growth stages, hoeing tillage was effective for reducing runoff and enhancing rainfall infiltration. By contrast, hoeing tillage enhanced soil and water conservation during the late growth stages. The total soil loss from HT plot (509.0 g/m2) was 11.1% higher than that from NH plot (457.9 g/m2) in R1–R5. However, the infiltration amount from HT plot (313.9 mm) was 18.4% higher than that from NH plot (265.0 mm) and the total runoff volume from HT plot was 49.7% less than that from NH plot. These results indicated that crop vegetation can also act as a type of vegetation cover and play an important role on sloping farmland. Thus, adopting rational soil management in crop planting on sloping farmland can effectively reduce runoff and soil loss, as well as maximize rainwater infiltration during crop growth period.
基金This work is supported by the National Natural Science Foundation of China (No. 40572038).
文摘Morphological and chemical studies on zircon grains from gabbro and granite of the Pingtan magmatic complex, Fujian Province, eastern China, show that there are three stages of zircon growth. The early stage of zircon growth is characterized by colorlessness, high transparence and birefringence, low and dispersive Ipr and Ipy, weak and homogeneous BSE brightness, lower Hf content and depletion of U, Th and Y; the middle stage is characterized by abruptly increasing lpy, progressively strong and sectoral-zoning BSE brightness, higher Hf content and enrichment of U, Th and Y with Th/U 〉 1; the late stage of growth is characterized by brownish color, poor transparence, low birefringence, highest Ipr and Ipy, middle and oscillatorily-zoning BSE brightness, highest contents of Hf, U and Y with Th/U 〈 1. The stages are considered to be formed in a deep magma chamber, ascent passage and emplacement site, respectively. Due to the more or less long residual time of the magma chamber, the difference in age between the early and late stages of zircon might be great enough to be distinguished, which can be attributed to tectonic constraint for the magnlatism.
基金Funding was provided by the National Key Research and Development Program of China(2017YFD0301200,2018YFD0300803,2015BAD01B03)the Jiangsu Key Research and Development Program,China(BE2017369)the Jiangsu Agricultural Science and Technology Innovation Fund,China(JASTIF,CX(18)1002).
文摘Understanding the characteristics of rice productivity is of great importance for achieving high yield formation.However,such traits have not yet been studied for different ages of hydroponically grown long-mat rice seedlings(HLMS),which constitutes a new method of seedling cultivation.Field experiments were conducted to evaluate the effects of seedling age on the growth stage,photosynthesis characteristics,dry matter production,and yield of HLMS.A conventional japonica rice cultivar(Wuyunjing 24)and an indica hybrid rice cultivar(6 Liangyou 9368)were used as test materials.The results showed that the whole phase was shortened by 13-15 days for young seedlings(13-day-old)compared with old seedlings(27-day-old),which occurred because the growth process accelerated with the transplantation of young seedlings.As seedling age increased,the dry matter weight of stems of individual plants and of the population increased at the transplanting stage but decreased at the maturity stage(MS).Compared with that of 27-day-old seedlings,the average ratio of panicle weight to total plant dry weight of 13-day-old seedlings during a 2-year period increased by 3.71%for Wuyunjing 24 and by 3.78%for 6 Liangyou 9368 at the MS.Moreover,as seedling age increased,the leaf area index and photosynthetic potential decreased for both cultivars,and the photosynthetic rate markedly decreased at the heading stage(HS).With the exception of that of Wuyunjing 24 from the jointing stage to the HS in 2014,the crop growth rate was higher for young seedlings than for old seedlings.Grain yield significantly decreased with seedling age,but no significant difference was detected between the 13-and 20-day-old seedlings for either cultivar.Therefore,equilibrious and high biological yield formation,vigorous growth in the late stages,and high photosynthetic production capacity are important characteristics and causes of the efficient and sustainable output of photosynthetic systems and for achieving high yield formation in young transplanted seedlings(13-20-day-old).
基金supported by the National Key Research and Development Program (2019YFE0125500)University-Locality Integrative Development Project of Yantai (2020XDRHXMPT35)+1 种基金the National Natural Science Foundation of China (31971785 and41801245)the Graduate Training Project of China Agricultural University (JG2019004, JG202026, YW2020007, QYJC202101, and JG202102)。
文摘Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy structure across different growth stages has great impacts on wheat LCC estimation, known as growth stage effects. It will result in the heterogeneity of crop canopy at different growth stages, which would mask subtle spectral response of biochemistry variations. This study aims to explore spectral responses on the growth stage effects and establish LCC models suited for different growth stages. A total number of 864 pairwise samples of wheat canopy spectra and LCC values with 216 observations of each stage were sampled at the tillering, jointing, booting and heading stages in 2021. Firstly, statistical analysis of LCC and spectral response presented different distribution traits and typical spectral variations peak at 470, 520 and 680 nm. Correlation analysis between LCC and reflectance showed typical red edge shifts. Secondly, the testing model of partial least square(PLS) established by the entire datasets to validate the predictive performance at each stage yielded poor LCC estimation accuracy. The spectral wavelengths of red edge(RE) and blue edge(BE) shifts and the poor estimation capability motivated us to further explore the growth stage effects by establishing LCC models at respective growth periods.Finally, competitive adaptive reweighted sampling PLS(CARS-PLS), decision tree(DT) and random forest(RF) were used to select sensitive bands and establish LCC models at specific stages. Bayes optimisation was used to tune the hyperparameters of DT and RF regression. The modelling results indicated that CARS-PLS and DT did not extract specific wavelengths that could decrease the influences of growth stage effects. From the RF out-of-bag(OOB) evaluation, the sensitive wavelengths displayed consistent spectral shifts from BE to GP and from RE to RV from tillering to heading stages. Compared with CARS-PLS and DT,results of RF modelling yielded an estimation accuracy with deviation to performance(RPD) of 2.11, 2.02,3.21 and 3.02, which can accommodate the growth stage effects. Thus, this study explores spectral response on growth stage effects and provides models for chlorophyll content estimation to satisfy the requirement of high-throughput phenotyping.
文摘The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.
基金Supported by Project of Study on the Impact of Climate Change on Wheat Production in Weifang City(2011wfqxkt05)
文摘In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were simulated by using the regional climate model PRECIS.And then put the meteorological data into the crop model to simulate the growth of wheat under climate change conditions in the future.The results showed that there would be a trend of rising temperature and increasing precipitation in Weifang in the future.Climate warming would result in growth period of wheat to be ahead of schedule and yield reduction.If taking into account the effect of CO2,the yield of wheat would increase.
文摘The dynamics of sap flow in relation to plant morphology and weather conditions during reproductive growth of soybean (Glycine max. L. Merr.) influence decisions pertaining to efficient irrigation management and other inputs for high yields. Field studies began in 2017 at Marianna, Arkansas to measure moisture dynamics of soybeans during seed fill (R5 to R7) using heat balance stem flow gauges. Sap flow was highly correlated to solar radiation with maximum rates observed during beginning seed fill (R5). A solar radiation efficiency (SRE) value, calculated as hourly sap flow rate per Watt-hour of solar radiation (g/Wh2), is proposed. The SRE relates to crop water demand and hydraulic resistance of the soil-root-stem-leaf-pod-seed pathway. SRE values ranged from 0 - 1.2 g/Wh2. Soil moisture, growth stage, time of day, and weather conditions influenced the SRE, with higher values observed in the morning, late afternoon, and during R5 growth. Peak sap flows of 39 g/h at R5, 25 g/h at R6, and 3 g/h at R7 occurred. The ratio of measured sap flow to estimated crop evapotranspiration was 0.9 to 1.3 during R5 to R6.9 (maximum dry matter), but dropped to 0.2 at R7. Further research is needed to better understand late season reproductive moisture dynamics in soybeans.
文摘The pathogen of tomato powdery mildew (Oidium neolycopersici Kiss) was simultaneously inoculated into four varieties during seedling, flowering and fruiting stages under the same environmental conditions by inducing inoculation method, so as to study the resistance during different growth stages. Different varieties of plants and the plants during different growth stages were investigated after inoculation for 12 d, and disease epidemic curves were drawn according to survey data. The results showed that different varieties performed different resistance against powdery mildew and the same variety also showed different resistance during different growth stages. The susceptible extent of Lujia was the heaviest during seedling and flowering sages, while it showed the strongest resistance during fruiting stage; improved 96 -8 showed the highest resistance during seedling stage, but performed the lowest resistance during fruiting stage.
基金supported by the talent cultivation and developmental support program of China Agricultural University,an award to study the cultivation of high-quality mutton sheep varieties(or lines)from Ningxia province(NXNYYZ20150101)the Natural Science Foundation of Hebei Province of China for Youths(C2019402261).
文摘Background:Tan sheep,an important local sheep breed in China,is famous for their fur quality.One-month-old Tan sheep have white,curly hair with beautiful flower spikes,commonly known as“nine bends”,which has high economic value.However,the“nine bends”characteristic gradually disappears with age;consequently,the economic value of the Tan sheep decreases.Age-related changes in DNA methylation have been reported and may be responsible for age-induced changes in gene expression.Until now,no genome-wide surveys have been conducted to identify potential DNA methylation sites involved in different sheep growth stages.In this study we investigated the dynamic changes of genome-wide DNA methylation profiles in Tan sheep using DNA from skin and deep whole-genome bisulfite sequencing,and compared the DNA methylation levels at three different growth stages:1,24,and 48 months old(mon1,mon24,and mon48,respectively).Results:In this study,11 skin samples from three growth stages(four for mon1,four for mon24,and three for mon48)were used for DNA methylation analysis and gene expression profiling.There were 52,288 and 236 differentially methylated genes(DMGs)identified between mon1 and mon24,mon1 and mon48,and mon24 and mon48,respectively.Of the differentially methylated regions,1.11%,7.61%,and 7.65% were in the promoter in mon1 vs.mon24,mon24 vs.mon48,and mon1 vs.mon48,respectively.DMGs were enriched in the MAPK and WNT signaling pathways,which are related to age growth and hair follicle morphogenesis processes.There were 51 DMGs associated with age growth and curly fleece formation.Four DMGs between mon1 and mon48(KRT71,CD44,ROR2 and ZDHHC13)were further validated by bisulfite sequencing.Conclusions:This study revealed dynamic changes in the genomic methylation profiles of mon1,mon24,and mon48 sheep,and the percentages of methylated cytosines were 3.38%,2.85% and 4.17%,respectively.Of the DMGs,KRT71 and CD44 were highly methylated in mon1,and ROR2 and ZDHHC13 were highly methylated in mon48.These findings provide foundational information that may be used to develop strategies for potentially retaining the lamb fur and thus improving the economic value of Tan sheep.
文摘The initial stage of Ag film growth on Cu(100). Ta(100) and Ta(110) single crystals as well as YBaCuO on Si single crystal covered by Pd was investigated in situ by means of LAS 600 surface analysis system with a sputtering source in sample preparation chamber. The results show that the initial state for Ag / Cu(100) film growth is typical S-K model, for Ag / Ta(100) and Ag / Ta(110)they have the same S-K characteristics, but due to the different surface energies of two crystalline planes. there is some difference for Ag / Ta (100) and Ag / Ta(110). YBCO sputterjng process is rather complex and Cu is the first element appearing in the film.
基金Supported by Liupanshui Planned Project (52020-2021-01-03)Guizhou Provincial and Municipal Science and Technology Cooperation Project (52020-2015-01-02)Guizhou Science and Technology Planning Project (QKHNYZ[2012]3020)
文摘The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi Special Zone of Guizhou Province in 2021 and combining with the meteorological data of temperature and precipitation in the base in the same period.The results showed that Hongyang,Donghong and Jinhong all sprouted on February 1,and had the same response to temperature and precipitation.From germination to leaf spreading stage,Hongyang and Donghong had the same response to precipitation,while Donghong and Jinhong had the same response to temperature,but Jinhong needed 32.5 mm precipitation to meet its growth and development.From leaf spreading stage to budding stage,Hongyang and Donghong had similar responses to temperature and precipitation,while Jinhong needed average daily temperature of 16.5℃and precipitation of 2.1 mm.The responses of the three varieties from budding to flowering to temperature and precipitation were consistent.From flowering to fruiting,Hongyang needed 19.9℃temperature and the least precipitation,while Jinhong needed the lowest temperature and the maximum precipitation.Donghong's response to temperature and precipitation was between Hongyang and Jinhong.During the period from fruit setting to fruit ripening and picking,Hongyang needed the least temperature and precipitation,while Donghong and Jinhong had the same response to temperature and precipitation.In the key period of fruit expansion of the three kiwifruit varieties in 2021,temperature and precipitation were the most suitable for fruit expansion.In short,red cartridge kiwifruit has a good response to temperature and precipitation in different growth stages,and it requires 201 d for Hongyang variety from germination to maturity and picking,211 d for Donghong variety and 218 d for Jinhong variety.