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    Crop Genetics · Breeding · Germplasm Resources
    Combining Phytate/Ca2+ Fractionation with Trichloroacetic Acid/Acetone Precipitation Improved Separation of Low-Abundant Proteins of Wheat (Triticum aestivum L.) Leaf for Proteomic Analysis
    Muhammad A R F Sultan, LIU Hui, CHENG Yu-Feng, ZHANG Pei-pei , ZHAO Hui-xian
    2013, 12(7): 1123-1129.  DOI: 10.1016/S2095-3119(13)60344-5
    Abstract ( )   PDF in ScienceDirect  
    Proteomic assessment of low-abundance leaf proteins is hindered by the large quantity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) present within plant leaf tissues. In the present study, total proteins were extracted from wheat (Triticum aestivum L.) leaves by a conventional trichloroacetic acid (TCA)/acetone method and a protocol first developed in this work. Phytate/Ca2+ fractionation and TCA/acetone precipitation were combined to design an improved TCA/acetone method. The extracted proteins were analysed by two-dimensional gel electrophoresis (2-DE). The resulting 2-DE images were compared to reveal major differences. The results showed that large quantities of Rubisco were deleted from wheat leaf proteins prepared by the improved method. As many as (758±4) protein spots were detected from 2-DE images of protein extracts obtained by the improved method, 130 more than those detected by the TCA/acetone method. Further analysis indicated that more protein spots could be detected at regions of pI 4.00-4.99 and 6.50-7.00 in the improved method-based 2-DE images. Our findings indicated that the improved method is an efficient protein preparation protocol for separating low-abundance proteins in wheat leaf tissues by 2-DE analysis. The proposed protocol is simple, fast, inexpensive and also applicable to protein preparations of other plants.
    Genetic Relationships Among Chinese Maize OPVs Based on SSR Markers
    SONG Li-ya, LIU Xue, CHEN Wei-guo, HAO Zhuan-fang, BAI Li , ZHANG De-gui
    2013, 12(7): 1130-1137.  DOI: 10.1016/S2095-3119(13)60341-X
    Abstract ( )   PDF in ScienceDirect  
    Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR primers. The purposes of this study were to (1) compare the genetic diversity among 44 Chinese maize open-pollinated varieties; (2) estimate the minimum number of alleles for construction of a stable dendrogram; and (3) trace the genetic relationships among local germplasm from different regions of China. In total, these 70 SSR primers yielded 292 alleles in 176 samples (4×44) analyzed. The number of alleles per locus was 4.17 on average and ranged from 2 to 8. The highest number of alleles per open-pollinated variety (55.25) was detected in Shanxi germplasm, which indicated that open-pollinated varieties from Shanxi possessed the largest genetic diversity among those from the five locations. The correlation coefficients between different genetic similarity matrices suggested that 200 alleles were sufficient for analysis of the genetic diversity of these 44 open-pollinated varieties. The cluster analysis showed that 44 open-pollinated varieties collected from three growing regions in China were accurately classified into three groups that were highly consistent with their geographic origins, and there is no correlation between GS and geographic distance in this study.
    Construction of a New Molecular Barcode for Discriminating Plants and Animals with a Close Genetic Relationship
    HUANG Li, ZHAO Xiao-feng, ZHU Yi-peng, DONG Heng, XU Ning-ying , CAO Jia-shu,
    2013, 12(7): 1138-1151.  DOI: 10.1016/S1671-2927(00)8925
    Abstract ( )   PDF in ScienceDirect  
    DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism (F-AFLP) and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.
    Characterization of NPR1 Genes from Norton and Cabernet Sauvignon Grapevine
    ZHANG Yi-ming, NI Xi-lu, MA Hui-qin , Wenping Qiu
    2013, 12(7): 1152-1161.  DOI: 10.1016/S2095-3119(13)60432-3
    Abstract ( )   PDF in ScienceDirect  
    Non-expressor of pathogenesis-related genes 1 (NPR1) plays a significant role in the defense responses of plants to pathogens by regulating the expression of defense-related genes. In the present study, we isolated two NPR1 genes from Vitis aestivalis cv. Norton and Vitis vinifera cv. Cabernet Sauvignon, which were referred to as VaNPR1.1 and VvNPR1. 1-CS, respectively. They encode a protein of 584 amino acids with a predicted molecular weight of 64.8 kDa and a theoretical isoelectric point (pI) of 5.74. The predicted amino acid sequences of VaNPR1.1 and VvNPR1.1-CS differ by only one amino acid. Over-expression of VaNPR1.1 gene in Arabidopsis npr1-1 mutant plants restores the transcriptional expression of AtPR-1 gene, though not to the full scale. This result demonstrated that a grapevine VaNPR1.1 possesses a similar function to the Arabidopsis NPR1 in the regulation of defense-related genes. Over-expression of VaNPR1.1 in transgenic Arabidopsis plant increased tolerance to salinity, but had no effect on the drought tolerance. We conclude that VaNPR1.1 is a functional ortholog of AtNPR1 and also involved in grapevine’s response to the salt stress.
    Physiology & Biochentry · Tillage · Cultivation
    Exploring the Feasibility of Winter Wheat Freeze Injury by Integrating Grey System Model with RS and GIS
    WANG Hui-fang, GUO wei, WANG Ji-hua, HUANG Wen-jiang, GU Xiao-he, DONG Ying-ying, XU Xin-gang
    2013, 12(7): 1162-1172.  DOI: 10.1016/S1671-2927(00)8927
    Abstract ( )   PDF in ScienceDirect  
    Winter wheat freeze injury is one of the main agro-meteorological disasters affecting wheat production. In order to evaluate the severity of freeze injury on winter wheat systematically, we proposed a grey-system model (GSM) to monitor the degree and the distribution of the winter wheat freeze injury. The model combines remote sensing (RS) and geographic information system (GIS) technology. It gave examples of wheat freeze injury monitoring applications in Gaocheng and Jinzhou of Hebei Province, China. We carried out a quantitative evaluation method study on the severity of winter wheat freeze injury. First, a grey relational analysis (GRA) was conducted. At the same time, the weights of the stressful factors were determined. Then a wheat freezing injury stress multiple factor spatial matrix was constructed using spatial interpolation technology. Finally, a winter wheat freeze damage evaluation model was established through grey clustering algorithm (GCA), and classifying the study area into three sub-areas, affected by severe, medium or light disasters. The evaluation model were verified by the Kappa model, the overall accuracy reached 78.82% and the Kappa coefficient was 0.6754. Therefore, through integration of GSM with RS images as well as GIS analysis, quantitative evaluation and study of winter wheat freeze disasters can be conducted objectively and accurately, making the evaluation model more scientific.
    Study on Plant Morphological Traits and Production Characteristics of Super High-Yielding Soybean
    AO Xue, ZHAO Ming-hui, ZHU Qian, LI Jie, ZHANG Hui-jun, WANG Hai-ying, YU Cui-mei, LI Chunhong, YAO Xing-dong, XIE Fu-ti , HAN Xiao-ri
    2013, 12(7): 1173-1182.  DOI: 10.1016/S2095-3119(13)60444-X
    Abstract ( )   PDF in ScienceDirect  
    Super high-yielding soybean cultivar Liaodou 14, soybean cultivars from Ohio in the United States, and the common soybean cultivars from Liaoning Province, China, with similar geographic latitudes and identical pod-bearing habits were used as the study materials for a comparison of morphological traits and production characteristics to provide a theoretical basis for the breeding of improved super high-yielding soybean cultivars. Using a randomized block design, different soybean cultivars from the same latitude were compared under conventional and unconventional treatments for their production characteristics, including morphological traits, leaf area index (LAI), net photosynthesis rate, and dry matter accumulation. The specific characteristics of the super high-yielding soybean cultivar Liaodou 14 were analyzed. The results showed that the plant height of Liaodou 14 was significantly lower than that of the common cultivars from Liaoning, whereas the number of its main-stem nodes was higher than that of the cultivars from Ohio or Liaoning. A high pod density was observed in Liaodou 14 under conventional treatments. Under both conventional and unconventional treatments, the branch number of Liaodou 14 was markedly higher than that of the common cultivars from Liaoning, and its branch length and leaf inclination angle were significantly higher than those of common cultivars from Liaoning or Ohio. Only small changes in the leaf inclination angle were observed in Liaodou 14 treated with conventional or unconventional methods. Under each treatment, Liaodou 14 exhibited the lowest amplitude of reduction in SPAD values and net photosynthesis rates from the grain-filling to ripening stages; the cultivars from Ohio and the common cultivars from Liaoning exhibited more significant reductions. Liaodou 14 reached its peak LAI later than the other cultivars but maintained its LAI at a higher level for a longer duration. Under both conventional and unconventional treatments, Liaodou 14 produced a higher yield than the other two cultivars, with significant differences from the Ohio cultivars. In summary, super high-yielding soybean cultivars have several main features: suitable plant height, high pod density, good leaf structure with strong functionality, and slow leaf senescence at the late reproductive stage, which is conducive to the accumulation of dry matter and improved yield.
    Interactive Effect of GA3, N and P Ameliorate Growth, Seed and Fibre Yield by Enhancing Photosynthetic Capacity and Carbonic Anhydrase Activity of Linseed: A Dual Purpose Crop
    Mohammad N Khan, Firoz Mohammad
    2013, 12(7): 1183-1194.  DOI: 10.1016/S2095-3119(13)60443-8
    Abstract ( )   PDF in ScienceDirect  
    Linseed (Linum usitatissimum L.) is an important dual-purpose, industrial crop. Its seeds are used for the extraction of oil and stem for fibres. However, the production of linseed is not going parallel with the increasing demand of its products. The present work was carried out with an aim to find out whether exogenous application of gibberellic acid (GA3) with or without graded levels of nitrogen (N) and phosphorus (P) could improve the performance of three linseed genotypes Parvati, Shekhar and Shubhra together with minimizing the costly fertilizer input and losses. Four combinations of N and P, viz., 0 mg N+0 mg P kg-1 soil (N0P0), N13.4P4.46, N26.8P8.94 and N40.2P13.4 were constituted. Half dose of each combination was applied basally at the time of sowing and remaining half dose was given at 40 d after sowing (DAS) as foliar spray along with 10-6 mol L-1 GA3. Prior to sowing, the seeds of each linseed genotype were grouped in to two, one group of seeds was soaked in 0 mol L-1 GA3 (control) and the other group was soaked in 10-6 M GA3 solution, each for 8 hours. Treatments were comprised of (i) 0 mol L-1 GA3+N0P0 (T0, control), (ii) 10-6 mol L-1 GA3 + N13.4P4.46 (T1), (iii) 10-6 mol L-1 GA3+N26.8P8.94 (T2) and (iv) 10-6 mol L-1 GA3+N40.2P13.4 (T3). The crop performance was assessed in terms of growth, physiological and biochemical parameters at 60 and 75 DAS and yield attributes at harvest (175 DAS). The results showed a parallel increase in most of the parameters with increasing levels of N and P. However, application of 10-6 mol L-1 GA3 in association with N26.8P8.94 proved best, it enhanced seed yield, oil yield and fibre yield by 83.3, 97.3 and 78.7%, respectively accompanied with increase in net photosynthetic rate, carbonic anhydrase activity and dry matter accumulation. Among the genotypes tested, Shubhra performed best, while Parvati the least for most of the parameters studied. Thus, combined application of 10-6 mol L-1 GA3 plus N26.8P8.94 proved best and can be recommended to exploit the linseed as a dual-purpose crop for good yield of seed and fibre.
    Plant Protection
    Sequencing and Phylogenetic Analysis of Potato virus Y Liaoning Isolate in China
    WANG Fang, GAO Zheng-liang, AN Meng-nan, ZHOU Ben-guo , WU Yuan-hua
    2013, 12(7): 1195-1200.  DOI: 10.1016/S2095-3119(13)60442-6
    Abstract ( )   PDF in ScienceDirect  
    Complete genome sequence of Potato virus Y Liaoning isolate (PVY-LN) causing tobacco vein necrosis symptoms were isolated from Liaoning Province in China. Genome sequences of PVY-LN was 9 714 nucleotides in length, excluding the 3´- terminal poly (A) tail. PVY-LN encodes a single long open reading frame (ORF) of polyprotein that is predicted to be cleaved into ten mature proteins by three viral proteases. No recombination can be predicted in PVY-LN sequences compared with that of the other PVY strains using Recombination Detection Programe v. 4.16 (RDP4). Complete genome sequence comparison and phylogenetic analysis indicated that PVY-LN is closely related to PVY necrosis strain (PVYN).
    Evaluation of Curvularia lunata Strain B6 as a Potential Mycoherbicide to Control Barnydrgrass (Echinochloa crus-galli)
    LI Jing, WEI Tao, SUN Ai-rui , NI Han-wen
    2013, 12(7): 1201-1207.  DOI: 10.1016/S2095-3119(13)60441-4
    Abstract ( )   PDF in ScienceDirect  
    The virulent strain B6 of Curvularia lunata was screened out from 65 fungus strains isolated from the diseased leaves of barnyardgrass (Echinochloa crus-galli). Greenhouse and field studies were conducted to evaluate the feasibility of the strain being exploited as a mycoherbicide for barnyardgrass control in paddy fields. The results of pathogenicity experiments showed that this strain was highly pathogenic to barnyardgrass at the 1- to 2.5-leaf stages. The fresh weight reduction increased with the increase of inoculated conidial concentrations and the prolongation of dew duration. Strain B6 provided excellent barnyardgrass control when it was applied at the concentration of 1×104-1×106 conidia mL-1 in paddy fields with water layer. This strain was very safe to rice and the most plant species except wheat, barley and corn. Findings of this study indicated that this strain could be a potential mycoherbicide for barnyardgrass control in paddy fields in the future.
    Effects of High-Quality Aromatic Rice Varieties on the Fitness of the Striped Stem Borer, Chilo suppressalis (Walker) in Central China
    DU Xue-zhu, WANG Yong, CHEN Long-jia, PENG Chuan-hua, MA Wei-hua, LEI Chao-liang
    2013, 12(7): 1208-1214.  DOI: 10.1016/S2095-3119(13)60446-3
    Abstract ( )   PDF in ScienceDirect  
    The striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is a major pest of rice in China. Variation in host-plant quality may affect the body size of herbivorous insects, which in turn, can determine their lifehistory parameters such as survival, fecundity and fitness. In this study, we tested the effects of high-quality aromatic rice varieties on the fitness of SSB in China. Results showed that 1st instar larvae had higher penetrating rates and survival rates on the high-quality aromatic rice varieties (EX-1 and WX-988) than that on the non-aromatic rice varieties (EZ-5 and LYP-9). In addition, shorter developmental periods, greater female pupal weights and higher of other life-history parameters (hatching rate, pupation rate, eclosion rate and increase index) were found on the high-quality aromatic rice varieties, although only female pupal weight showed a significant difference between the two varieties. The highest dead heart rate was found on the aromatic rice variety of EX-1. These results indicate that SSB sustains a lower fitness cost when consuming the high-quality aromatic rice varieties (EX-1 and WX-988) than on the non-aromatic rice varieties (EZ-5 and LYP-9) in Central China.
    Animal Science · Veterinary Science
    The Virosome as a Novel Concept for High Pathogenic Porcine Reproductive and Respiratory Syndrome Virus (HP-PRRSV) Vaccines
    CAO Zheng, Lü Feng-lin
    2013, 12(7): 1215-1224.  DOI: 10.1016/S2095-3119(13)60440-2
    Abstract ( )   PDF in ScienceDirect  
    Porcine reproductive and respiratory syndrome virus (PRRSV) is an envelope, positive, single-strand RNA virus and is a member of the Arteriviridae family, Nidovirales order. PRRSV is the viral pathogen responsible for porcine reproductive and respiratory syndrome (PRRS) and caused reproductive failure and high rate of late abortion and early farrowing in sows and respiratory disease in all age. In 2006, a large scale outbreak of atypical PRRS occurred in China is characterized by high fever (41-42°C), high morbidity (50-100%) and high mortality (20-100%). The disease was caused by a highly pathogenic PRRSV with a 30 amino acid deletions in its Nsp2 coding region. Because the PRRSV strains are genetically heterogeneous, and elicit delayed and weak cell-mediated immune (CMI) and antibody responses after vaccination the current vaccines are failed to provide sustainable disease control. Virosomes are virus-like particles, consisting of reconstituted virus envelopes without genetic material of the native virus. Since the virosomes has being similar to the original virus in terms of morphology and cell entry characteristics. Virosomes provide a vaccine platform that has the capacity to combine the antigen and an adjuvant within a single particle that could activate both the humoral and the cellular arm of the immune system. Furthermore, the virosomes are also providing a novel promising approach for the development of an efficacious vaccine against HP-PRRSV.
    Dynamic Change of Genetic Diversity in Conserved Populations with Different Initial Genetic Architectures
    LU Yun-feng, LI Hong-wei, WU Ke-liang, WU Chang-xin
    2013, 12(7): 1225-1233.  DOI: 10.1016/S2095-3119(13)60439-6
    Abstract ( )   PDF in ScienceDirect  
    Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is the retention of genetic diversity of conserved populations in a long-term perspective. However, numerous factors may affect evolution of genetic diversity of a conserved population. Among those factors, the genetic architecture of conserved populations is little considered in current conservation strategies. In this study, we investigated the dynamic changes of genetic diversity of conserved populations with two scenarios on initial genetic architectures by computer simulation in which thirty polymorphic microsatellite loci were chosen to represent genetic architecture of the populations with observed heterozygosity (Ho) and expected heterozygosity (He), observed and mean effective number of alleles (Ao and Ae), number of polymorphic loci (NP) and the percentage of polymorphic loci (PP), number of rare alleles (RA) and number of non-rich polymorphic loci (NRP) as the estimates of genetic diversity. The two scenarios on genetic architecture were taken into account, namely, one conserved population with same allele frequency (AS) and another one with actual allele frequency (AA). The results showed that the magnitude of loss of genetic diversity is associated with genetic architecture of initial conserved population, the amplitude of genetic diversity decline in the context AS was more narrow extent than those in context AA, the ranges of decline of Ho and Ao were about 4 and 2 times in AA compared with that in AS, respectively, the occurrence of first monomorphic locus and the time of change of measure NP in scenario AA is 20 generations and 23 generations earlier than that in scenario AS, respectively. Additionally, we found that NRP, a novel measure proposed by our research group, was a proper estimate for monitoring the evolution of genetic diversity in a closed conserved population. Our study suggested that current managements of conserved populations should emphasize on initial genetic architecture in order to make an effective and feasible conservation scheme.
    In vitro Ruminal Gas Production Kinetics of Four Fodder Trees Ensiled With or Without Molasses and Urea
    Abdelfattah Z M Salem, ZHOU Chuan-she, TAN Zhi-liang, Miguel Mellado, Moises Cipriano Salazar, Mona M M Y Elghopur , Nicholas E Odongo
    2013, 12(7): 1234-1242.  DOI: 10.1016/S2095-3119(13)60438-4
    Abstract ( )   PDF in ScienceDirect  
    This study investigated if the addition of urea (U), molasses (M) or their 1:1 (v/v) mixture during ensiling increases the nutritional value of forage from four fodder trees (Prunus persica, Leucaena esculenta, Acacia farnesiana, and Prunus domestica). Forage samples of fodder trees were collected in triplicate (three individual samples of each species) and subjected to an in vitro gas production (GP) procedure. Fermentation at 24 h (GP24), short-chain volatile fatty acids (SCFA), and microbial crude protein production (MCP), in vitro organic matter digestibility (OMD), metabolizable energy (ME) and dry matter degradability (DMD) were estimated. Forage samples were incubated for 72 h in an incubator at 39ºC and the volume of GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation using the reading pressure technique. The rumen fermentation profiles were highest for P. persica, which showed the highest (P<0.0001) DMD, ME, OMD, SCFA, GP24 and MCP. On the other hand L. esculenta had the lowest (P<0.0001) DMD, SCFA, MCP; P. domestica had the lowest (P<0.0001) OMD. The addition of M to silage increased (P<0.0001) ME and OMD, as well as GP. However, the addition of U and the mixture of U and M reduced (P<0.0001) DMD, ME, OMD, SCFA, GY24 and MCP. These results show that P. persica has the highest nutritive value and L. esculenta the lowest for ruminants. Additionally, the addition of M to forage from fodder trees increases rumen GP and fermentation, which may improve nutrient utilization in ruminants.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Improving Water Use Efficiency of Wheat Crop Varieties in the North China Plain: Review and Analysis
    MEI Xu-rong, ZHONG Xiu-li, Vadez Vincent , LIU Xiao-ying
    2013, 12(7): 1243-1250.  DOI: 10.1016/S2095-3119(13)60437-2
    Abstract ( )   PDF in ScienceDirect  
    The North China Plain (NCP), one of the most important agricultural regions in China, is facing a major water-resource crisis evoked by excessive exploitation of groundwater. To reduce water use while maintaining high crop production level, improving variety water use efficiency (WUE) is an urgent need, especially because other water-saving measures such as water delivery, irrigation, and agricultural practices have already achieved most possible progresses. Evaluation of variety WUE can be performed accurately at the individual plant level (WUEp). Reviewing the studies on physiological factors affecting WUEp performed up to date, stomatal conductance was considered to be an important trait associating closely with WUEp. The trait showed a large degree of varietal variability under well-watered conditions. Crop varieties differ highly in sensitivity of stomata to soil and air drying, with some varieties strongly reducing their stomatal conductance in contrast with those lightly regulating their stomata. As a result, difference among varieties in WUEp was enlarged under water deficit conditions in contrast with those under well-watered conditions. The relationship between stomatal conductance and yield depends on water availability of whole growing period in local areas. Usually, large stomatal conductance results in a high yield under good irrigation system, whereas a low stomatal conductance can lead to yield benefit under limited stored soil moisture conditions. In the NCP, winter wheat is the largest consumer of irrigation water, improvement strategies for high WUE aiming at wheat crops are in urgent need. We suggest, for the well-irrigated areas with excessive exploitation of groundwater, the wheat breeding program need to combine medium stomatal conductance (0.35 mmol H2O m-2 s-1 or so), high carboxylation efficiency, and high harvest index. Areas with partial/full access to irrigation, or infrequent drought, should target wheat varieties with high stomatal conductance under no water stress and low sensitivity of stomata to soil water deficit. Drought-prone rain-fed areas characterized by frequent and long terminal drought should target wheat varieties with low stomatal conductance under no water stress and high stomata sensitivity to soil drying to make water available during grain filling.
    Effect of Temperature, pH and Salt on Fluorescent Quality of Water Extractable Organic Matter in Black Soil
    LI Ming-tang, ZHAO Lan-po , ZHANG Jin-jing
    2013, 12(7): 1251-1257.  DOI: 10.1016/S2095-3119(13)60436-0
    Abstract ( )   PDF in ScienceDirect  
    Water erosion is the major reason for the loss of soil organic carbon in the Northeast China, which leads to the soil quality deterioration and adjacent water pollution. In this study, the effect of extraction temperature, pH value, and salt on the water extractable organic matter (WEOM) was determined by means of the UV absorbance, fluorescence excitationemission matrix, and derived fluorescence indexes. In general, the carbon content and aromaticity of WEOM increased with the increasing of extraction temperature, with the exception that there was no significant difference in the amount at 0 and 20°C. More fluorophores, especially microbially-derived organic matter were extracted at high temperature. The pH values of extractant, including 5, 7, and 10, showed no effect on the carbon amount of WEOM, whereas the aromaticity and microbially-derived component gradually increased with the increasing of pH values. The fluorescence intensity of humic acid-like fluorophore was stronger in neutral and alkali condition than that in acidic condition. The addition of 10 mmol L-1 CaCl2 significantly decreased the carbon amount of recovered WEOM. Moreover, it significantly decreased the aromaticity of WEOM and the quantity of fulvic acid-like and humic acid-like fluorophores, whereas increased the percentage of tyrosine-like and tryptophan-like fluorophores in the total fluorophores and the amount of microbially-derived organic matter. Generally, 10 mmol L-1 KCl showed the same influence trend, but with low influence degree.
    Pretreatment of Rice Straw by Hydrogen Peroxide for Enhanced Methane Yield
    SONG Zi-lin, YAG Gai-he, FENG Yong-zhong, REN Guang-xin, HAN Xin-hui
    2013, 12(7): 1258-1266.  DOI: 10.1016/S2095-3119(13)60355-X
    Abstract ( )   PDF in ScienceDirect  
    A pretreatment process for hydrogen peroxide (H2O2) was optimized to enhance the biodegradation performance of rice straw and increase biogas yield. A determination experiment was conducted under predicted optimal conditions. Optimization was implemented using response surface methodology. The effects of biodegradation and the interactive effects of pretreatment time (PT), H2O2 concentration (HC), and substrate to inoculum ratio (S/I) on methane yield were investigated. The lignin, cellulose, and hemicellulose of rice straw were significantly degraded with increasing HC. The optimal conditions for the use of pretreated rice straw in anaerobic digestion were a 6.18-d PT, 2.68% HC (w/w total solid), and 1.08 S/I; these conditions result in a methane yield of 288 mL g-1 volatile solids (VS). A determination coefficient of 95.2% was obtained, indicating that the model used to predict the anabolic digestion process has a favorable fit with the experimental parameters. The determination experiment resulted in a methane yield of 290 mL g-1 VS, 88.0% higher than that of untreated rice straw. Thus, H2O2 pretreatment of rice straw can be used to improve methane yields during biogas production.
    Agricultural Economics And Management
    Impacts of Climate Change on Water and Agricultural Production in Ten Large River Basins in China
    WANG Jin-xia, HUANG Ji-kun , YAN Ting-ting
    2013, 12(7): 1267-1278.  DOI: 10.1016/S2095-3119(13)60421-9
    Abstract ( )   PDF in ScienceDirect  
    The overall goal of this paper is to examine impacts of climate change on water supply and demand balance and their consequences on agricultural production in ten river basins in China. To realize this goal, China Water Simulation Model (CWSM) is used to analyze three alternative climate scenarios (A1B, A2 and B2). The results show that the impacts of climate change on water supply and demand balance differ largely among alternative scenarios. While significant impacts of climate change on water balance will occur under the A1B scenario, the impacts of climate change under the A2 and B2 scenarios will be marginal. Under the A1B scenario, the water shortage in the river basins located in the northern China will become more serious, particularly in Liaohe and Haihe river basins, but the other river basins in the southern China will improve their water balance situations. Despite larger impacts of climate change on water balance in the northern China, its impacts on total crops’ production will be moderate if farmers would be able to reallocate water among crops and adjust irrigated and rainfed land. The paper concludes with some policy implications.
    Climate Change, Risk and Grain Yields in China
    Rainer Holst, Xiaohua Yu , Carola Grün
    2013, 12(7): 1279-1291.  DOI: 10.1016/S2095-3119(13)60435-9
    Abstract ( )   PDF in ScienceDirect  
    Adopting Just and Pope (1978, 1979) style yield functions, this paper proposes a method to analyze the impacts of regional climate change on grain production in China. We find that changes in climate will affect grain production in North and South China differently. Specifically, it emerges that a 1°C increase in annual average temperature could reduce national grain output by 1.45% (1.74% reduction in North China and 1.19% reduction in South China), while an increase in total annual precipitation of around 100 mm could increase national grain output by 1.31% (3.0% increase in North China and 0.59% reduction in South China).
    Assessing Agricultural Sustainable Development Based on the DPSIR Approach: Case Study in Jiangsu, China
    ZHOU Shu-dong, Felix Mueller, Benjamin Burkhard, CAO Xing-jin , HOU Ying
    2013, 12(7): 1292-1299.  DOI: 10.1016/S2095-3119(13)60434-7
    Abstract ( )   PDF in ScienceDirect  
    According to the contemporary ecosystem approach, the linkages of human actions with their environment have to be assessed in an integrative manner. The Driver-Pressure-State-Impact-Response (DPSIR) model is applied to identify and describe processes and interactions in human-environmental systems. An example application from a research project dealing with the development of sustainable management strategies for the agriculture in Jiangsu, China, illustrates the potentials and limitations of its sustainable development. The concept and indicators of ecological integrity are used to assess the indicators in the dimensions of DPSIR between 2003 and 2006. The main drivers included population growth which caused increasing demand for food, growing environmental demands, and rapidly decreasing of land and other natural resources. The main environmental problem was water pollution. The results show that in the dimension of driver, total grain output and agricultural land productivity both increased. Labor intensive agriculture has been promoted to increase agricultural land productivity. In the dimension of pressure, on the positive side, infrastructure got greatly improved, the input level such as total power of machinery, and level of fertilizer use increased, and level of pesticides use decreased, but on the negative side, cultivated land per capita and irrigation rate decreased, natural resources keep decreased. Environmental pollution indicators such as industrial wastewater discharge and acid rain rate increased in Jiangsu Province. In the aspect of state, ecosystem state was improved, plant coverage index increased, biological abundance index increased, fertilizer productivity increased, eco-environmental quality index increased, but land degradation index also increased. In the aspect of impact, output level increased, output efficiency enhanced, farmer’s social economic benefit improved. In the aspect of response, social support was greatly improved, input for environmental governance increased. To assess the effects of environmental governance, Jiangsu government was successful to increase compliance rate of sulfur dioxide emissions, but not so efficient in compliance rate of industrial wastewater discharge.
    Short Communication
    Survey of Tetracyclines, Sulfonamides, Sulfamethazine, and Quinolones in UHT Milk in China Market
    HAN Rong-wei, ZHENG Nan, WANG Jia-qi, ZHEN Yun-peng, LI Song-li , YU Qun-li
    2013, 12(7): 1300-1305.  DOI: 10.1016/S2095-3119(13)60433-5
    Abstract ( )   PDF in ScienceDirect  
    This study surveyed 180 samples of ultra high temperature (UHT) milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the ELISA method. The percentages of tetracyclines, sulfonamides, sulfamethazine, and quinolones detected in the samples were 0, 16.7, 40.6, and 100%, respectively. The maximum concentrations of the tetracyclines, sulfonamides, sulfamethazine and quinolones in UHT milk samples were <1.5, 26.2, 22.6, and 58.8 μg kg-1, respectively. None of the samples exceeded the maximum residue levels (MRLs) for these four veterinary drugs, according to the regulations set by China, the European Union (EU) and the Codex Alimentarius Commission (CAC).