For Selected: Toggle Thumbnails
    Crop Genetics · Breeding · Germplasm Resources
    Comparison and Analysis of QTLs, Epistatic Effects and QTL×Environment Interactions for Yield Traits Using DH and RILs Populations in Rice
    ZHAO Xin-hua, QIN Yang, JIA Bao-yan, Suk-Man Kim, Hyun-Suk Lee, Moo-Young Eun, Kyung-Min
    2013, 12(2): 198-208.  DOI: 10.1016/S2095-3119(13)60219-1
    Abstract ( )   PDF in ScienceDirect  
    Two genetic linkage maps, constructed by DH and RILs populations derived from the same parents, were carried out for the identification and comparison of QTLs controlling yield traits across different years in rice (Oryza sativa L.). A total of 194 SSR and STS markers were used in two maps, of which 114 markers were same. The distribution of Samgang allele was higher in RILs population than it in DH population. Comparing with DH population, RILs population has more lines with higher yield and wider phenotypic transgressive segression for yield traits. Although most of QTLs for the same trait were different in two populations across different years, 8 QTLs (including gwp11.1, spp5.1, spp10.1, spp11.2, ssr1.1, ssr11.1, tgw9.1 and tgw11.1) were detected over 2 yr. It is important to note that ppp10.1, spp10.1 and tgw9.1 were identified in two populations, while spp10.1 and tgw9.1 were simultaneity observed across different years. Epistatic effects were more important than additive effects for PPP, SPP, yield in DH population and TGW, yield in RILs population. Epistatic effects of DH and RILs populations were different on the same genetic background in the present study, which illuminated the QE interaction played an important role on epistatic effect. Identification and comparison of QTLs for yield traits in DH and RILs populations should provide various and more precise information. The QTLs identified in present study would be valuable in marker-assisted selection program for improving rice yield.
    Wheat 14-3-3 Protein Conferring Growth Retardation in Arabidopsis
    LI Jing, SONG Su-sheng, ZHAO Yu-sheng, GUO Wei-wei, GUO Guang-hui, PENG Hui-ru, NI Zhong-fu
    2013, 12(2): 209-217.  DOI: 10.1016/S2095-3119(13)60220-8
    Abstract ( )   PDF in ScienceDirect  
    14-3-3 proteins belong to a family of phosphoserine/threonine-binding modules and participate in a wide array of signal transduction and regulatory events. Our previous study demonstrated that Ta14-3-3 was significantly down-regulated in leaf and root tissues of hybrid wheat at the tillering stage. In this paper, three homoeologous Ta14-3-3 genes were cloned from common wheat (Triticum aestivum L., 2n=6x=42, AABBDD) and mapped on chromosomes 2A, 2B, and 2D, respectively. Transgenic Arabidopsis plants ectopically overexpressing Ta14-3-3 displayed shorter primary roots, delayed flowering and retarded growth rates, indicating that Ta14-3-3 acted as a growth inhibitor in Arabidopsis. In wheat, Ta14-3-3 was down-regulated in roots and leaves of hybrids as compared to their parental lines. We proposed that Ta14-3-3 proteins might regulate growth vigor in hybrid wheat.
    QTL Mapping for Stalk Related Traits in Maize (Zea mays L.) Under Different Densities
    ZHU Li-ying, CHEN Jing-tang, Li Ding, ZHANG Jian-hua, HUANG Ya-qun, ZHAO Yong-feng, SONG Zhan-quan , LIU Zhi-zeng
    2013, 12(2): 218-228.  DOI: 10.1016/S2095-3119(13)60221-X
    Abstract ( )   PDF in ScienceDirect  
    Stalk related traits, comprising plant height (PH), ear height (EH), internode number (IN), average internode length (AIL), stalk diameter (SD), and ear height coefficient (EHC), are significantly correlated with yield, density tolerance, and lodging resistance in maize. To investigate the genetic basis for stalk related traits, a doubled haploid (DH) population derived from a cross between NX531 and NX110 were evauluated under two densities over 2 yr. The additive quantitative trait loci (QTLs), epistatic QTLs were detected using inclusive composite interval mapping and QTL-by-environment interaction were detected using mixed linear model. Differences between the two densities were significant for the six traits in the DH population. A linkage map that covered 1 721.19 cM with an average interval of 10.50 cM was constructed with 164 simple sequence repeat (SSR). Two, two, seven, six, two, and eight additive QTLs for PH, IN, AIL, EH, SD, and EHC, respectively. The extend of their contribution to penotypic variation ranged from 10.10 to 31.93%. Seven QTLs were indentified simultaneously under both densities. One pair, two pairs and one pair of epistatic effects were detected for AIL, SD and EHC, respectively. No epistatic effects were detected for PH, EH, and IN. Nineteen QTLs with environment interactions were detected and their contribution to phenotypic variation ranged from 0.43 to 1.89%. Some QTLs were stably detected under different environments or genetic backgrounds comparing with previous studies. These QTLs could be useful for genetic improvement of stalk related traits in maize breeding.
    Discovery of MicroRNAs Associated with the S Type Cytoplasmic Male Sterility in Maize
    YU Jiang-hua, ZHAO Yan-xin, QIN Ya-ting, YUE Bing, ZHENG Yong-lian , XIAO Hai-lin
    2013, 12(2): 229-238.  DOI: 10.1016/S2095-3119(13)60222-1
    Abstract ( )   PDF in ScienceDirect  
    MicroRNAs (miRNAs) are endogenous small RNAs that play important regulatory roles in the growth and development processes of plants and animals. In this study, we examined the expression profiles of pollen miRNAs from a maize S type cytoplasmic male sterile line and its fertility restored line. In total, 100 known miRNAs belonging to 20 families and 81 novel miRNAs belonging to 44 families were identified. Two and seven known miRNAs had significant expression difference between the two lines at the level of P-value<0.01 and 0.011.5 fold expression difference were verified by stem-loop RT-qPCR. Gene Ontology analysis of miRNA target genes revealed that these genes mainly participated in the transcriptional regulation processes.
    Nitric Oxide Content in Wheat Leaves and Its Relation to Programmed Cell Death of Main Stem and Tillers Under Different Nitrogen Levels
    GUO Jun-xiang, CHEN Er-ying, YIN Yan-ping, WANG Ping, LI Yong, CHEN Xiao-guang, WU Guanglei
    2013, 12(2): 239-250.  DOI: 10.1016/S2095-3119(13)60223-3
    Abstract ( )   PDF in ScienceDirect  
    Nitric oxide (NO) is a key signaling molecule in different physiological processes of plants, including programmed cell death (PCD). PCD of tillers plays an important role in surviving which are major components of grain yield. PCD was triggered in wheat leaves of main stem and tillers by NO content under different nitrogen treatments. In wheat, NO could be synthesized endogenously by nitrate reductase (NR). As an inducible enzyme, NR activity was closely related to substrate concentration. Therefore, different nitrogen levels would change NR activity and NO production. The objective of this study was to determine the effects of NR activity, NO production, and the correlation between them on different tillers growth, development, senescence, and kernel protein content under different nitrogen levels. Field-experiments were conducted in 2009-2011 growing seasons, using two wheat cultivars with different spike-types. Results showed that for main stem and primary tillers, NR activity and NO content reached high level at heading stage, while for secondary tiller, the level of NR activity was low, but NO content was high in the present research. The NO synthesis depending on NR activity in wheat leaves was significant in the early growing stage, but the NO synthesis weakened with the progress of growing period. NO was related to the senescence of wheat leaves, but PCD was more sensitive to marked changes of NO content than NO content itself. N application had marked influence on the aging process of primary tiller, while had little influence on that of main stem and secondary tiller. Moreover, N fertilizer application could increase spike rate and protein content of primary tiller by N fertilizer application.
    Regulatory Function of Polyamine Oxidase-Generated Hydrogen Peroxide in Ethylene-Induced Stomatal Closure in Arabidopsis thaliana
    HOU Zhi-hui, LIU Guo-hua, HOU Li-xia, WANG Lan-xiang , LIU Xin
    2013, 12(2): 251-262.  DOI: 10.1016/S2095-3119(13)60224-5
    Abstract ( )   PDF in ScienceDirect  
    Hydrogen peroxide (H2O2) is an important signaling molecule in ethylene-induced stomatal closure in Arabidopsis thaliana. Early studies on the sources of H2O2 mainly focused on NADPH oxidases and cell-wall peroxidases. Here, we report the involvement of polyamine oxidases (PAOs) in ethylene-induced H2O2 production in guard cells. In Arabidopsis epidermal peels, application of PAO inhibitors caused the failure of ethylene to induce H2O2 production and stomatal closure. Results of quantitative RT-PCR analysis and pharmacological experiments showed that AtPAO2 and AtPAO4 transcripts and activities of PAOs were both induced by ethylene. In transgenic Arabidopsis plants over-expressing AtPAO2 and AtPAO4, stomatal movement was more sensitive to ethylene treatment and H2O2 production was also significantly induced. The increased H2O2 production in the transgenic lines compared to the wild-type plants suggests that AtPAO2 and AtPAO4 probably are involved in ethylene-induced H2O2 production. Several factors which induce stomatal closure such as dehydration and high salinity all enhanced the expression of AtPAO2 and AtPAO4 to different degrees. Moreover, GFPAtPAOs fusion protein localized in the nucleus, cytoplasm, and cell wall of the guard cells. Therefore, our results strongly indicated that PAO is a source of H2O2 generation in Arabidopsis guard cells and plays crucial roles in stomatal movement.
    Coupling Effects of Irrigation and Phosphorus Fertilizer Applications on Phosphorus Uptake and Use Efficiency of Winter Wheat
    WANG Yu, CHI Shu-yun, NING Tang-yuan, TIAN Shen-zhong , LI Zeng-jia
    2013, 12(2): 263-272.  DOI: 10.1016/S2095-3119(13)60225-7
    Abstract ( )   PDF in ScienceDirect  
    The water content and nutrient in soil are two main determine factors to crop yield and quality, managements of which in field are of great importance to maintain sustainable high yield. The objective of this study was to measure the uptake, forms, and use efficiency of phosphorus (P) in wheat under four levels of irrigation (W0, W1, W2, and W3) and three levels of P application (P0, P1, and P2) through two growth seasons of wheat (2008-2010). The field experiment was carried out in a low level of soil P concentration and the cultivar was Jimai 20. The results indicated that P fertilizer combined with irrigation not only improved the activity of phosphatase in soil, but also increased P accumulation in wheat, similar results was found in the grain of wheat, the content of total P increased significantly. Meanwhile, the mainly existence forms of P in grain were the lecithoid-P and labile organic-P. On the other hand, in comparison to the irrigation, the dry matter and grain P production efficiency and postponing P application of wheat increased with increasing P application rates within the range of 0-180 kg P2O5 ha-1. The interaction between P and irrigation also significantly (P<0.01) affected on the P accumulation, grain total P, grain phospholipid P, and P production efficiency. In this study, therefore, the P applications and irrigation improved grain P production efficiency and postponing P application of winter wheat, and W2P2 treatment (180 kg P2O5 ha-1 combination with 120 mm irrigation) had a high P accumulation and P use efficiency, it was an optimum level for P fertilizer application and irrigation in this region.
    Evaluation of Harvest Aid Chemicals for the Cotton-Winter Wheat Double Cropping System
    DU Ming-wei, REN Xiao-ming, TIAN Xiao-li, DUAN Liu-sheng, ZHANG Ming-cai, TAN Wei-ming , LI Zhao-hu
    2013, 12(2): 273-282.  DOI: 10.1016/S2095-3119(13)60226-9
    Abstract ( )   PDF in ScienceDirect  
    Timing of harvest is critical for mechanical picking in cotton production, especially in those regions with double cropping system. Appropriate and safe harvest aids will improve timing and facilitate harvest of cotton in the double cropping system. Three defoliants (dimethipin, thidiazuron, and thidiazuron-diuron) and one boll opener (ethephon) were included in this research. They were evaluated for their effects on defoliation, boll opening, seedcotton yield, seed quality, and fiber quality of field grown cotton when used alone or as a mixture in 2009 and 2010. Defoliation and/or boll opening were increased by all three defoliants and ethephon, especially by mixtures of a defoliant and ethephon. First harvest of seedcotton was significantly increased with defoliant-ethephon mixtures. No significant adverse effects were observed on boll weight, lint percentage, seed quality, and fiber properties. It was estimated that tank mixes of ethephon and one of the three defoliants can improve the adjusted gross revenue. Boll opening can be used as an alternative indicator for the adjusted gross revenue, because, it was linearly and positively correlated with the relative adjusted gross revenue and convenient in measurements. Wheat seedling growth was not affected by thidiazuron, whereas its seedling emergence, root dry weight, relative water content, and electrolyte leakage were adversely affected by dimethipin and thidiazurondiuron when concentration was above 340 and 100 g (a.i.) ha-1, respectively. 90% defoliation and 80% boll opening were observed with the high rate of thidiazuron-ethephon mixture, but no adverse effects on winter wheat. The results suggested that tank mixes of ethephon with thidiazuron can be used effectively and safely in the cotton-winter wheat double cropping system to improve yield without adverse effects on seed quality and fiber quality.
    Wolbachia Infection in Populations of Ostrinia furnacalis: Diversity, Prevalence, Phylogeny and Evidence for Horizontal Transmission
    LI Jing, WANG Zhen-ying, Denis Bourguet , HE Kang-lai
    2013, 12(2): 283-295.  DOI: 10.1016/S2095-3119(13)60227-0
    Abstract ( )   PDF in ScienceDirect  
    Wolbachia are maternally inherited endosymbiotic bacteria infecting a wide range of arthropods and filarial nematodes. They can induce various reproduction alterations in their hosts, including thelytokous parthenogenesis, cytoplasmic incompatibility (CI), feminization of genetic males and male killing. Here we investigated diversity and prevalence patterns of Wolbachia infection in 43 geographical populations of the Asian corn borer, Ostrinia furnacalis, in China and one population in North Korea. Based on Wolbachia surface protein gene (wsp) sequences, nine strains of Wolbachia (wFur1-wFur9), belonging to supergroups A and B, were identified in populations of O. furnacalis with an average infection rate of 10.5%. Superinfection commonly appeared in individuals of O. furnacalis and coinfection patterns were very complex. There was no specific pattern for the prevalence and distribution of the nine Wolbachia strains suggesting an intricate evolutionary history of Wolbachia infection in this species. The genetic similarity of the wFur1-wFur9 strains with those detected in two parasitoids of O. furnacalis, Macrocentrus cingulum and Lydella grisescens, strongly suggests host-parasitoid horizontal transmission.
    Responses of Detoxifying, Antioxidant and Digestive Enzyme Activities to Host Shift of Bemisia tabaci (Hemiptera: Aleyrodidae)
    DENG Pan, CHEN Long-jia, ZHANG Zong-lei, LIN Ke-jian , MA Wei-hua
    2013, 12(2): 296-304.  DOI: 10.1016/S2095-3119(13)60228-2
    Abstract ( )   PDF in ScienceDirect  
    The polyphagous B-biotype of Bemisia tabaci (Gennadius) has demonstrated a high capacity to adapt to numerous hosts from diverse plant families. To illustrate induced responses by the host plant, biochemical research on eight plant-insect interaction correlative enzymes, representing detoxifying, antioxidant and digestive pathways, were investigated. Transferring whitefly adults to Zhongmian 23 from the pre-adapted host Zhongmian 41 induced activities of carboxylesterase (by 1.80-fold), glutathione S-transferase (by 3.79-fold), proteinase (by 1.62-fold) and amylase (by 2.41-fold) activities, but decreased polyphenol oxidase (by 1.89-fold) and peroxidase (by 1.88-fold). However, transferring whitefly adults to the favorite host abutilon from Zhongmian 41 was associated with increased activities of cytochrome P450 monooxygenase (by 1.61-fold) and amylase (by 1.42-fold), and decreased activities of polyphenol oxidase (by 2.96-fold) and peroxidase (by 2.07-fold). Our results, together with previous studies, proved that multiple pathways are involved in coping with host shifts by polyphagous herbivores, and the taxonomic status and preference of the host transferred would affect which pathway would be induced. These results would represent a key challenge in developing long-term sustainable insect control strategies.
    Impact of Long-Term Atrazine Use on Groundwater Safety in Jilin Province, China
    GENG Yue, MA Jing, JIA Ran, XUE Li-qin, TAO Chuan-jiang, LI Chong-jiu, MA Xiao-dong , LIN Yan
    2013, 12(2): 305-313.  DOI: 10.1016/S2095-3119(13)60229-4
    Abstract ( )   PDF in ScienceDirect  
    The long-lasting application of representative herbicide atrazine (ATR) has given rise to the accumulation of its residues in the groundwater. To investigate the impact of long-term ATR use on groundwater safety, the residues of ATR and its metabolites, desethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HA) were monitored in groundwater and top soil at the major corn growing region of Qian’an and Gongzhuling in Jilin Province, China. The residues of the target compounds were analyzed by UPLC-MS/MS. The limits of detection (LODs) of ATR, DEA, DIA, and HA were 0.5, 0.5, 5, and 0.5 ng L-1 in groundwater and 0.33, 0.33, 3.3, and 0.33 μg kg-1 in soil. The target compounds were found in 94% of groundwater samples and 100% of soil samples. The compounds detected most frequently in groundwater were ATR (89%), DEA (64%) and HA (17%), whereas in soil were ATR (97%), DEA (36%) and HA (97%). DIA was not detected in any determined groundwater and soil sample. Average residues were 106.8 ng L-1 for ATR, 0.9 ng L-1 for DEA and 0.3 ng L-1 for HA in groundwater, whereas 11.1 μg kg-1 for ATR, 0.4 μg kg-1 for DEA and 7.8 μg kg-1 for HA in soil. ATR residues detected in groundwater samples were below standards for drinking water quality (GB5749-2006, 2 μg L-1), while the total residues of ATR and its chloro-s-triazine metabolites (DEA and DIA) were below current WHO (World Health Organization) guideline value (GV, 0.1 mg L-1). In addition, concentrations of HA in groundwater were determined below current WHO GV (0.2 mg L-1). The results indicated that ATR is safe to be used in Jilin Province under the current application scheme. However, total residues of ATR and DEA were detected in nearly all wells, thus, it is necessary to pay attention on groundwater monitoring for ATR and its metabolites.
    Microbial Community in the Forestomachs of Alpacas (Lama pacos) and Sheep (Ovis aries)
    PEI Cai-xia, LIU Qiang, DONG Chang-sheng, LI Hong-quan, JIANG Jun-bing , GAO Wen-jun
    2013, 12(2): 314-318.  DOI: 10.1016/S2095-3119(13)60230-0
    Abstract ( )   PDF in ScienceDirect  
    Four 2-yr old alpacas ((48±2.3) kg) and four 2-yr old sheep ((50±1.7) kg) were used to study the pH and microbial community of forestomach from alpacas (Lama pacos) and sheep (Ovis aries) fed fresh alfalfa as the sole forage at low altitude (793 m). The forestomach fluid was taken anaerobically via the esophagus. The electric pH meter and quantitative polymerase chain reaction systems were used to study the the pH and microbial community of forestomach. The results showed that the mean pH of forestomach fluid from alpacas was higher than that from sheep (P<0.01). The percentages of methanogens and Ruminococcus flavefaciens to total bacterial were lower in the forestomach of alpacas than that in the rumen of sheep, while the percentage of fungi and Fibrobacter succinogenes were higher. The percentage of protozoa was similar in the forestomach of alpacas and sheep. These differences can partly explain the reason that alpacas were lower methane production than sheep.
    Effects of Increasing Non-Fiber Carbohydrate to Neutral Detergent Fiber Ratio on Rumen Fermentation and Microbiota in Goats
    LIU Da-cheng, ZHOU Xiang-li, ZHAO Pei-ting, GAO Min, HAN Hao-qi, , HUHong-lian
    2013, 12(2): 319-326.  DOI: 10.1016/S2095-3119(13)60231-2
    Abstract ( )   PDF in ScienceDirect  
    Six rumen-cannulated lactating Guanzhong goats were used to investigate changes in ruminal fermentation pattern and the microbiota following a subacute ruminal acidosis (SARA) inducing procedure. Induction of SARA was performed by increasing dietary non-fiber carbohydrate (NFC) to neutral detergent fiber (NDF) ratio from 1.02 (stage 1) to 1.24 (stage 2), 1.63 (stage 3) and 2.58 (stage 4). A dynamic pH monitoring system, real-time fluorescent quantitative PCR and conventional anaerobic culture were used to assess changes in ruminal pH and microbiota. Results indicated that rumen fermentation patterns changed significantly with increased NFC:NDF ratio. The decline in ruminal pH was caused by increased ruminal total volatile fatty acids (TVFA), which was mainly attributed to a significant increase in ruminal butyrate, rather than the accumulation of ruminal lactic acid. In addition, in the course of SARA, the number of rumen microoganisms altered significantly, with increases in ruminal amylolytic bacteria, Lactobacilli, Streptococcus bovis and Megasphaera elsdenii, the latter particularly dramatically indicating that it may be the main factor responsible for the increase in butyrate, and decrease in protozoa
    Identification and Characterization of Putative Virulent Genes in Streptococcus equi ssp. zooepidemicus
    ZHOU Hong, MA Zhe, YUAN Jin , FAN Hong-jie
    2013, 12(2): 327-333.  DOI: 10.1016/S2095-3119(13)60232-4
    Abstract ( )   PDF in ScienceDirect  
    Suppression subtractive hybridization (SSH) was performed with virulent strain ATCC35246 and avirulent strain ST171 to identify novel genes associated with virulence in Streptococcus equi ssp. zooepidemicus (SEZ). There were fourteen genomic regions that only presented in virulent strain ATCC35246. These regions encoded 14 proteins, some of them were homologous to proteins associated with cellular surface structure, molecular synthesis, energy metabolism, regulation, transport systems, and other unknown functions. Primers for 6 particular regions were designed from the already published SEZ sequence. Then, we used PCR to evaluate the distribution and conservation of these 6 DNA fragments in various SEZ strains collected from different sources, regions, groups, and times. The results showed that these 6 DNA fragments were widely distributed in SEZ strains, yet they were not existence in the avirulent strain ST171. Moreover, these fragments could not be detected in other Streptococcus groups.
    Pathogenesis of Demyelinating Encephalopathy in Dogs with Spontaneous Acute Canine Distemper
    PAN Yao-qian, LIU Xing-you, MENG Li-ping, ZHU Guang-rui, XIA Yin-ke, CHEN Jin-shan , Yoshikawa Takashi
    2013, 12(2): 334-343.  DOI: 10.1016/S2095-3119(13)60233-6
    Abstract ( )   PDF in ScienceDirect  
    So far, the pathogenesis of demyelination caused by canine distemper virus (CDV) in the central nervous system has remained unclear, although a lot of studies have been done extensively. To further investigate the relation of variety cells in brain to demyelination, this study was performed on 15 dogs with spontaneous acute canine distemper and 2 controls. According to anatomical relation, the brain was divided into cerebrum, cerebral stem and cerebellum. The sections with no, mild, moderate, or severe demyelinating lesions were selected respectively and stained by HE and immunohistochemistry. Immuno-localisation of CDV antigen was used to confirm CDV infection. The brain was examined for co-localisation of the CDV antigen with either an astrocyte-specific marker, glial fibrillary acidic protein (GFAP), or an oligodendrocyte-specific marker, galactocerebroside (GalC). Apoptotic cell was detected by TdT-mediated nick end-labeling assay (TUNEL). The results demonstrated that the local disturbance of blood circulation mainly included congestion, edema, thrombosis, and disseminated intravascular coagulation (DIC). The CDV neucleocapsid protein positive reaction, metabolic disorder and apoptosis of oligodendrocytes were observed in demyelinating areas. Lots of astrocytes displayed CDV antigen-positive, especially in their process. Some of them became apoptotic cell confirmed by TUNEL staining. Fibrous astrocytes showed more intense GFAP-positive in mild and moderate demyelinating area. Some of nervous cells located in pyramidal cell layers and nucleus nervi were in degeneration, necrosis. Satellitosis, neuronophagia and apoptotic neurons were examined by hematoxylin and eosin (HE) and TUNEL staining. The results suggested that the demyelinating changes in brain tissues infected with CDV mainly related to the metabolic disorder and apoptosis of ogliodendrocytes and astrocytes; also involved with the local disturbance of blood circulation and some neuron lost.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Spatial Distribution of Soil Organic Matter and Nutrients in the Pear Orchard Under Clean and Sod Cultivation Models
    XU Ling-fei, ZHOU Peng, HAN Qing-fang, LI Zhi-hui, YANG Bao-ping , NIE Jun-feng
    2013, 12(2): 344-351.  DOI: 10.1016/S2095-3119(13)60234-8
    Abstract ( )   PDF in ScienceDirect  
    The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil of the pear (cv. Dangshansu on P.betulifolia Bunge. rootstock) orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil organic matter (SOM), total nitrogen (STN), total phosphorus (STP), total potassium (STK), available nitrogen (SAN), and available potassium (SAK) in and between rows at different soil depths (0-60 cm). The SOM, STN, STP, STK, SAN and SAK of the different soil layers under the two tillage models were different in the vertical direction. The SOM, STN, STP and SAN in the 0-20 cm soil layer were higher than those in the 20-40 and 40- 60 cm soil layers. The STK of 40-60 cm soil layer was higher than that in the 0-20 and 20-40 cm soil layers. The STK increased with the depth of soil in the vertical direction in the clean cultivated pear orchard. Variability of the SOM, STN, STP, STK, SAN and SAK of sample sites in between rows of the same soil layer was found in the pear orchard soil in the horizontal direction under clean and sod cultivation management systems, except that STK of all sites did not show the difference in identical soil layers in the pear orchard under clean cultivation. The sod cultivation model improved the SOM, STN, and STK in the 0-20 cm soil layer in the pear orchard, and the three components increased by 12.8, 12.7 and 7.3% compared to clean cultivation, respectively. The results can be applicable to plan collection of orchard soil samples, assess orchard soil quality, and improve orchard soil management practices.
    Cold Damage Risk Assessment of Double Cropping Rice in Hunan, China
    CHENG Yong-xiang, HUANG Jing-feng, HAN Zhong-ling, GUO Jian-ping, ZHAO Yan-xia, WANG Xiu-zhen , GUO Rui-fang
    2013, 12(2): 352-363.  DOI: 10.1016/S2095-3119(13)60235-X
    Abstract ( )   PDF in ScienceDirect  
    Combined with remote sensing data and meteorological data, cold damage risk was assessed for planting area of double cropping rice (DCR) in Hunan Province, China. A new methodology of cold damage risk assessment was built that apply to grid and have clear hazard-affected body. Each station cold damage annual frequency and average annual intensity of cold damage was calculated by using 1951-2010 station daily mean temperature and simple cold damage identification index. On this basis, average annual cold damage risk index was obtained by their product. The spatial analysis models of cold damage risk index about double-season early rice (DSER) and double-season later rice (DSLR) were established respectively by the relation of average annual cold damage risk index and its geographic factors. Critical threshold of level of average annual cold damage risk index for DSER and DSLR were respectively divided by the correlative equation of cold damage annual frequency and average annual intensity of cold damage. 2001-2010 planting area of DCR, acquired by time series analysis of MOD09A1 8-d composite land surface reflectance product, was as target of assessment. The results show average annual intensity of cold damage is exponential function of cold damage annual frequency, average annual cold damage risk index is directly proportional to cold damage cumulant and cold damage annual frequency, and is inversely proportional to happen times of cold damage and the square of statistical time sequence length. Cold damage risk of DSER is higher than DSLR in Hunan Province. In the 10-yr stacking map, DCR planting in low risk area accounted for 11.92% of total extraction area, in moderate risk area accounted for 69.62%, in high risk area accounted for 18.46%. According to the cold damage risk assessment result, DCR production can be guided to reduce cold damage losses.
    Farmer’s Adoption of Improved Nitrogen Management Strategies in Maize Production in China: an Experimental Knowledge Training
    JIA Xiang-ping, HUANG Ji-kun, XIANG Cheng, HOU Lin-ke, ZHANG Fu-suo, CHEN Xin-ping, CUIZhen-ling , Holger Bergmann
    2013, 12(2): 364-373.  DOI: 10.1016/S2095-3119(13)60237-3
    Abstract ( )   PDF in ScienceDirect  
    Chemical fertilizer plays an important role in increasing food production in China. Nevertheless, excessive nitrogen fertilizer use in China has resulted in severe environmental problems. The goal of this paper is to examine the impacts of an improved nitrogen management (INM) training experiment on farmers’ chemical nitrogen (N) use behaviors in maize production in China. Based on household data collected from 813 maize farmers in Shandong, China, this study finds that while INM training can significantly reduce farmers’ N fertilizer use, an INM training is not sufficient to change farmer’s practices significantly, and farmers only partially adopted the recommended INM. This study reveals that China faces challenges to transform its agriculture to a low-carbon one. The research also sheds light on China’s extension system and future technologies in meeting the objectives of reducing the excessive nitrogen fertilizer use in agricultural production.
    Spatial-Temporal Changes in Grain Production, Consumption and Driving Mechanism in China
    XU Shi-wei, WU Jian-zhai, SONG Wei, LI Zhi-qiang, LI Zhe-min , KONG Fan-tao
    2013, 12(2): 374-385.  DOI: 10.1016/S2095-3119(13)60236-1
    Abstract ( )   PDF in ScienceDirect  
    The spatial-temporal patterns of grain production and consumption have an important influence on the effective national grain supply on condition of tight balance in the total grain amount in China. In this paper, we analyze the spatial-temporal patterns of grain production, consumption and the driving mechanism for their evolution processes in China. The results indicate that both gravity centers of grain production and consumption in China moved toward the northern and eastern regions, almost in the same direction. The coordination of grain production and consumption increased slightly from 1995 to 2007 but decreased from 2000 to 2007. There is a spatial difference between the major districts of output increase and the strong growth potential in grain consumption, which indicates an increasing difficulty in improving the regional coordination of grain production and consumption. The movement of the gravity center of grain production is significantly correlated with regional differences in grain production policy, different economic development models, and spatial disparity of land and water resource use. For grain consumption, the main driving factors include rapid urbanization, the upgrade of food consumption structure, and distribution of food industries.