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1.
With consecutive occurrences of drought disasters in China in recent years, it is important to estimate their potential impacts on regional crop production. In this study, we detect the impacts of drought on wheat and maize yield and their changes at a 0.5°×0.5° grid scale in the wheat-maize rotation planting area in the North China Plain under the A1B climate change scenario using the Decision Support System for Agrotechnology Transfer (DSSAT) model and the outputs of the regional climate modeling system-Providing Regional Climates for Impacts Studies (PRECIS). Self-calibrating palmer drought severity index was used as drought recognition indicator. Two time slices used for the study were the baseline (1961-1990) and 40 years of 2011-2050. The results indicate that the potential planting region for double crop system of wheat-maize would expend northward. The statistic conclusions of crop simulations varied considerably between wheat and maize. In disaster-affected seasons, wheat yield would increase in the future compared with baseline yields, whereas in opposite for maize yield. Potential crop yield reductions caused by drought would be lower for wheat and higher for maize, with a similar trend found for the ratio of potential crop yield reductions for both crops. It appears that the negative impact of drought on maize was larger than that on wheat under climate change A1B scenario.  相似文献   

2.
Isoprenoids are a functionally and structurally diverse class of natural organic chemicals. The universal precursors of all isoprenoids, isopentenyl diphosphate and dimethylallyl diphosphate are synthesized through the mevalonate and 2C-methyl- D-erythritol 4-phosphate (MEP) pathways, respectively. Many isoprenoids produced through the MEP pathway play an important role in plant acclimation to different light environments. Eupatorium adenophorum, an invasive weed in China, presents a remarkable capacity to acclimate to various light environments, which constitutes its solid foundation of being a successful invasive species. Thus we aimed at gaining a deeper insight into the regulation of MEP pathway in E. adenophorum to further understand the invasive mechanism. 2C-Methyl-D-erythritol 2,4-cyclodiphosphate synthase (IspF or MCS) is an essential enzyme in the MEP pathway. In this paper, a novel IspF gene was cloned and characterized from E. adenophorum. Tissue-specific expression assays revealed a higher expression of EalspF1 in leaves than in stems and roots. The expression of EalspF1 was responsive to different light conditions. Some up-regulation of EalspF1 expression was also found after the treatments with signal compounds and after wounding stress. Interestingly, the over-expression of EalspF1 in Arabidopsis led to increase carotenoids contents, resulting in an enhanced tolerance to high light. Taken together, these results indicate that the EalspFl-derived enzyme participates in isoprenoid metabolism and among others, the expression of this gene in E. adenophorum is involved in the regulation of plastidial isoprenoids, which play an important role in acclimation to various light environments.  相似文献   

3.
Stress-associated protein (SAP) has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 (TaSAP1) members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight (TGW) in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low (19.29-26.67%). It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.  相似文献   

4.
Cellular retinoic acid-binding protein 1 (CRABP1) is a well-conserved member of cytosolic lipid-binding protein family. It is an important modulator of retinoic acid signaling. Long serial analysis of gene expression (LongSAGE) analysis suggested that CRABP1 gene was differentially expressed during prenatal skeletal muscle development in porcine. Here, we obtained the full-length coding region sequence and genomic sequence of the porcine CRABP1 gene and analyzed its genomic structures. Subsequently, we examined CRABP1 chromosome assignment using INRA-University of Minnesota 7 000 porcine radiation hybrid panel (IMpRH) and explored its tissue distribution in adult Tongcheng pigs and dynamical expression profiles in prenatal skeletal muscle (33, 65 and 90 days post coitus, dpc) from Landrace (lean-type) (described as L33, L65 and L90) and Tongcheng pigs (obese-type) (described as T33, T65 and T90). The CRABPI gene was mapped to chromosome 7ql 1-q23 and closely linked to the microsatellite marker SWR1928. Quantitative real-time PCR showed that CRABP1 mRNA was highly expressed in lung and stomach, moderately expressed in placenta and uterus, and weakly expressed in other tissues. Moreover, CRABP1 gene was down-regulated during prenatal skeletal muscle development in both Landrace and Tongcheng pigs and it was expressed much higher in T33 than L33. Two single-nucleotide polymorphisms (SNPs) were detected by sequencing and mass spectrometry methods, allele frequency analysis indicated that g. 281 (G〉A) and g. 2992 (G〉A)were deviated from Hardy-Weinberg equilibrium in the Landrace and DLY (Duroc×(Landrace×Yorkshire)) pig breeds.  相似文献   

5.
The study reflects on previous World Bank and FAO reports that made the general recommendation to set both research and extension investment targets in developing countries at 1% of agricultural gross domestic product (AgGDP). In order to define proxies for country-specific extension investment targets, authors developed an extension investment model (EIM) based on socio-economic macro-indicators (poverty, undernourishment, access to information and population density) and a method to define estimates for cost increases related to climate change. These parameters helped estimating the demand for agricultural extension and investments required for it. Results showed that about half of the 94 developing and emerging countries should spend more than 1% of their respective share of GDP derived from agriculture and about a quarter of the countries, mostly in Africa and South East Asia, need to spend more than 2% of their AgGDP. The paper reveals significant differences in average investment requirements in different regions and shows the additional extension costs related to climate change and other areas that currently lack investment.  相似文献   

6.
Inflammation in pulp tissue is caused by caries bacteria. Most bacteria found are Lactobacillus acidophilus. Propolis is a sticky resin material that is derived from the bees and the surrounding plants, which are reported to have several biological effects including anti-bacterial and anti-inflammatory. This study will prove the effectiveness of propolis against proinflammatory cytokines on odontoblast-like cells in human dental pulp. This study was performed on cultured odontoblast-like cells in pulp. Cell culture was derived from the pulp tissue of human M3 teeth that had been extracted. Odontoblast pulp culture was divided in three groups: group one, cultured cells with propolis; group two, cultured cells induced with inactive Lactobacillus acidophilus; group three, cultured cells induced with inactive Lactobacillus acidophilus and exposed to 3 μg/mL propolis. A measurement of TNF-α and TGF-β1 expression was done using the immunocytochemical technique to determine the effectiveness of propolis extracts from East Java Indonesia against proinfalmmatory cytokines. Data were analyzed using the analysis of variance (ANOVA) test (P = 0.05). Propolis extract can inhibit the expression of TNF-α and increase the expression of TGF-β1 on odontoblast-like cell in human dental pulp. Anti-inflammatory effects of East Java propolis extract are associated with cytokine modulation.  相似文献   

7.
对银白杨(Populus alba)×[白榆(Ulmus pumila)+新疆杨(P.alba var.pyramidalis)失活花粉]的亲本和子代进行了核型分析。结果表明:银白杨,2n=38=1M+30m(1SAT)+4sm+1st+2t;银榆杨(P.× alba L.‘yinyu’)1号,2n=38=1M+30m(1SAT)+4sm+1st+2t; 银榆杨2号,2n=38=1M+30m(2SAT)+4sm+1st+2t。白榆的染色体2n=28。银白杨和银榆杨的染色体数目相同,核型差异很小。随体的数量可能与银榆杨和银白杨表型不同有关。推测,银白杨×白榆的杂种胚在发育时先形成了以银白杨染色体为主的单倍体,后经染色体自然加倍形成二倍体银榆杨。  相似文献   

8.
9.
对春提早、秋延后和越冬茬西葫芦的叶面积指数(LAI)及生育期的有效积温进行归一化处理,分别将最大的LAI和出苗至开花的有效积温定为1,以相对LA(I0~1)和相对有效积温(0~1)为参数,进行LAI动态模拟,筛选、建立了一个适用于这3个茬口西葫芦的相对LAI动态模拟模型:y=(a+bx)(/1+cx+dx2)。其中,春提早为y=(-0.040 0+0.087 5x)/(1-1.473 8x+0.588 2x2)(r=0.992 2**,n=50);秋延后为y=(0.035 5+0.060 0x)(/1-1.390 5x+0.543 1x2)(r=0.991 9**,n=22);越冬茬为y=(-0.046 4+0.146 4x)(/1-1.377 9x+0.559 0x2)(r=0.988 7**,n=70)。准确度(以k表示)分别为0.999 6,1.000 7和1.000 5,精确度(以R2表示)分别为0.983 9,0.982 3和0.976 9。西葫芦LAI动态模型从三叶一心期就能够比较准确地进行西葫芦LAI动态预测。  相似文献   

10.
11.
To determine the genomic sequence of a duck hepatitis virus type 1 (DHV-1) strain, real-time quantitative polymerase chain reaction (RTQ-PCR) assay based on SYBR Green I technology was developed to target 3D gene of DHV-1, Comparative sequence analysis showed that the genome has a typical picornarivus genetic organization, and strain DHV-1 R genetic organaiztion is 5' untranslated region (UTR)-VP0-VP3-VPI-2A1-2A2-2B-2C-3A-3B-3C-3D-3' UTR, DHV-1 R has close relationship with Parechovirus, and has 95.1-99.1% nucleotide sequence identity with other DHV-1 strains. Based on the DHV-1 sequences in GenBank, three pairs of specific primers were designed to amplify DHV-1 using real-time PCR. The results showed that real-time PCR Tm value is 85.6℃ and the real-time PCR provides a broad dynamic range, detecting from 102 to 109 copies of DHV-1 cDNA per reaction. No cross-reactions were found in specimens containing DPV, AIV and NDV. It is concluded that DHV-1 belongs to a new group of the family Picornaviridae that may form a separate genus most closely related to the genus Parechovirus. All results showed that the real-time PCR has high sensitivity and specificity to detect DHV-1 using SYBR Green I dissociation curve analysis, isolates can be distinguished by their melting temperature. These methods are rapid, sensitive, and reliable, and can be readily adapted for detection of DHV-1 from other clinical samples.  相似文献   

12.
乌苏里江上游黑斑狗鱼种群的生长特性   总被引:5,自引:0,他引:5  
于2003年秋季对乌苏里江上游黑斑狗鱼Esoz reichertl的种群结构和生长特性进行了调查研究,共采集样本840尾。结果表明:该水域的黑斑狗鱼主要由6^+龄以下个体组成,其中以3^+龄以下个体为主。体长与体重之间的关系为形:0.0051L^3.1023(r=0.9762);生长方程为L1=120.17[1-e^0.1215(t+0.5983)],Wt=15139.22[1-e^-0.1215(t+0.5983)]^3.1023;生长拐点年龄t=8.7龄,拐点体重形=4531.7g,说明黑斑狗鱼在8^#龄前均能维持较快增长。鉴于目前的捕捞状况,应对4^#~8^#龄之间的个体适当加以保护。  相似文献   

13.
以2个品种人参菜为材料,采用石蜡切片结合荧光显微法,以及根尖压片法观察分析了2个品种人参菜形态结构和核型差异,以期为人参菜品种鉴别提供理论参考依据。结果表明:形态上,品种2的株高、茎粗、叶片厚度、单叶面积、花直径均显著大品种1,2个品种人参菜的花色、种子千粒重均无显著差异。显微结构上,品种1上表皮单位面积气孔数量显著小于品种2,而下表皮单位面积气孔数量显著大于品种2;花柱均呈三瓣羽毛状;品种1茎横截面近似圆形,品种2茎横截面呈不规则形状;品种1染色体数目为2n=2x=40,核型公式为2n=2x=38m+2M,染色体相对长度组成为8L+14M2+12M1+6S,核型类别属1B型,核型不对称系数为54.50%;品种2染色体数目为2n=2x=24,核型公式为2n=2x=18m+6sm,染色体相对长度组成为6L+4M2+8M1+6S,核型类别属2B型,核型不对称系数为59.37%。2个品种上下表皮单位面积气孔数量、茎横截面形状和核型差异较大,可以作为鉴别人参菜品种的参考指标。  相似文献   

14.
【目的】研究塔里木河流域开都河长身高原鳅的年龄与生长的关系。【方法】2017~2019年通过对塔里木河流域开都河长身高原鳅的采样观察,运用经典生物学测量方法鉴定年龄,分析其生长性状。【结果】开都河长身高原鳅,年龄均值为3.06±0.11+,年龄结构不符合正态分布,优势年龄个体2+;体长和体重相关方程为:W=0.013 3L2.809 4(R2=0.745 9);体长和肠长的关系式为: LI=0.730 L -2.74(R2=0.981 8);长身高原鳅渐进体长L∞=23.75 cm,生产系数k=0.64,W∞=97.42 g,t 0 = - 0.70,ti=9.14+ ;种群总体(n=139)体长和体重生长方程为:Lt = 23.75 (1-e-0.64 (t + 0.7)) 和Wt= 97.42 (1-e-0.64 (t + 0.7))2.809 4。种群总体成熟系数和丰满度:GSI=27.20±1.80和K=0.88±0.26。【结论】塔里木河流域开都河长身高原鳅属于异速生长,适应性较强,生长性状不稳定,在种群动态和渔业生态平衡,起到了一定的作用。  相似文献   

15.
采用"3414"二次回归D—最优设计,对影响水稻产量的氮、磷、钾三要素进行试验,建立融安县中低产红泥田双季晚稻施肥函数模型:y=3811.92+24.48N+6.3P+6.86K-0.10N2-0.43P2-0.09K2+0.13NP+0.01NK+0.23PK。通过该模型推算最高和最佳产量施肥量,并进行仿真模拟寻优,探索出产量大于5 700kg/hm2的施肥方案:N 135.8~195.8kg/hm2、P2O549.5~74.8kg/hm2、K2O 94.6~145.4kg/hm2,N∶P2O5∶K2O=1∶0.36~0.38∶0.70~0.74。  相似文献   

16.
石阡县黄泥田水稻氮磷钾肥配施试验初报   总被引:3,自引:1,他引:2  
针对石阡县主要水稻土种黄泥田进行"3414"氮磷钾肥配方施肥试验.得出,石阡县黄泥田水稻种植施肥数学模型为y=311.72+25.44x1+12.20x2+5.49x3-0.26x1x2+0.12x1x3+2.20x2x3-1.10x21-2.23x22-0.91x23;最佳施量为:667m2施N 10.487 kg、P 6.222 kg、K 9.267 kg,可获水稻产量533.991 kg/667m2.  相似文献   

17.
《农业科学与技术》2013,(10):1446-1450,1453
In order to investigate the resistance of female silkworm moths to cold storage and their copulation and oviposition after cold storage, copulation and ovipo- sition experiments of Liangguang 2 silkworms and Guican 1 female silkworm moths were conduced under cold storage at 5 ~C for different durations. The results indi- cated that, after cold storage at 5 ~C with relative humidity of 75%, the resistance of female silkworm moths to cold storage varied with different varieties; to be specific, 9-Fu and 7.Xiang, parent silkworm varieties of Liangguang 2 with ancestry of mul- tivoltinism, were relatively resistant to cold storage, and their copulation capability was still at a high level after cold storage for 72 h. Oviposition capability also varied with different varieties and durations; to be specific, under 5 ~C conditions, between two parent silkworm varieties of Liangguang 2, female silkworm moths of 9-Fu achieved the best results within cold storage duration of 24 h, female silkworm moths of 7.Xiang achieved the best results within cold storage duration of 72 h; be- tween two parent silkworm varieties of Guican 1, female silkworm moths of Xinhang achieved the best results without cold storage, female silkworm moths of 826 achieved the best results within cold storage duration of 48 h.  相似文献   

18.
The changes in humic substances (HS) is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances (WSS), humic acid (HA), fulvic acid (FA) and humin (HU) were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon (SOC) and HS (R^2=0.98, P〈0.01). The change in the E4/E6 ratio was significantly correlated with the increased SOC (R2=0.88, P〈0.01), HA (R^2=0.91, P〈0.01), FA (R^2=0.91, P〈0.01) and HU (R^2=0.88, P〈0.01). The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.  相似文献   

19.
The accurate assessment of the spatiotemporal changes in soil nutrients influenced by agricultural production provides the basis for development of management strategies to maintain soil fertility and balance soil nutrients. In this paper, we combined spatial measurements from 2 157 soil samples and geostatistical analysis to assess the spatiotemporal changes in soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP) and available potassium content (AK) from the first soil survey (in the 1980s) to the second soil survey (in the 2000s) in the Taihu region of Jiangsu Province in China. The results showed that average soil nutrients in three soil types all exhibited the increased levels in the 2000s (except for AK in the yellow brown soil). The standard deviation of soil nutrient contents increased (except for TN in the paddy soil). Agricultural production in the 20 years led to increases in SOC, TN, AP and AK by 74, 82, 89 and 65%, respectively, of the Taihu areas analyzed. From the 1980s to 2000s all the nugget/sill ratios of soil nutrients indices were between 25 and 75% (except for AK in the yellow brown soil in the 2000s), indicating moderate spatial dependence. The ratio of AP in the yellow brown soil in the 2000s was 88.74%, showing weak spatial dependence. The spatial correlation range values for SOC, TN, AP and AK in the 2000s all decreased. The main areas showing declines in SOC, TN and AP were in the northwest. For AK, the main region with declining levels was in the east and middle of western areas. Apparently, the increase in soil nutrients in the Taihu region can be mainly attributed to the large increase in fertilizer inputs, change in crop systems and enhanced residues management since the 1980s. Future emphasis should be placed on avoiding excess fertilizer inputs and balancing the effects of the fertilizers in soils.  相似文献   

20.
为研究红螯螯虾(Cherax quadricarinatus von Martens)不同生长时期的表型特征,统计了3月龄、4.5月龄和6月龄3个生长时期红螯螯虾的体重Y1、肝胰腺质量Y2、全长X1、头胸甲长X2、头胸甲宽X3、腹节总长X4、第一腹节长X5、第一腹节宽X6和掌节长X7共9个性状,对比3个生长时期各表型性状间的差异和相关性,分析不同生长时期各表型性状在雌性与雄性群体间的差异,采用多元回归分析分别研究了不同生长时期表型性状与体重的关系,并构建回归方程。结果显示,头胸甲和腹节的长度比例在幼虾和成虾中保持一致,而宽度指标(头胸甲宽、第一腹节宽)在6月龄阶段显著(P<0.05)增长。随着红螯螯虾的生长,大部分性状间的相关性降低,雌雄群体间表型性状的差异逐渐增加。3月龄阶段的回归方程为Y1=-31.33+0.73X2+0.91X3;4.5月龄阶段的回归方程分别为Y1=-65.25+1.29X3+0.89X4+1.46X6(雌性)、Y1=-69.67+1.17X3+0.40X7+1.77X6+0.59X4(雄性);6月龄阶段的回归方程分别为Y1=-79.77+1.01X1-1.89X6+1.15X7(雌性)、Y1=-98.02+0.72X1+1.22X7(雄性)。从3个生长时期的回归方程可以看出,各表型性状在不同时期与体重的相关性差异较大。研究结果可为红螯螯虾的选育工作提供理论依据。  相似文献   

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