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    Crop Genetics · Breeding · Germplasm Resources
    Identification of QTLs Underlying Folate Content in Milled Rice
    DONG Wei, CHENG Zhi-jun, XU Jian-long, ZHENG Tian-qing, WANG Xiao-le, ZHANG Hong-zheng, WANG Jie , WAN Jian-min
    2014, 13(8): 1827-1834.  DOI: 10.1016/S2095-3119(13)60537-7
    Abstract ( )   PDF in ScienceDirect  
    Understanding the genetic mechanism underlying folate biosynthesis and accumulation in rice would be beneficial for breeding high folate content varieties as a cost-effective approach to addressing widespread folate deficiency in developing countries. In this study, the inheritance of rice grain folate content was investigated in the Lemont/Teqing recombinant inbred lines and the Koshihikari/Kasalath//Koshihikari backcross inbred lines. 264 F12 recombinant inbred lines (RILs) and 182 BC1F10 backcross inbred lines (BILs) with their parents planted in randomized complete blocks with two replicates in 2010, and RILs harvested in 2008 were used for QTL detection using inclusive composite interval mapping (ICIM) method. In the RIL population, two QTLs, denoted by qQTF-3-1 and qQTF-3-2 (QTF, quantitative total folate), explaining 7.8% and 11.1-15.8% of the folate content variation were detected in one or two years, respectively. In the BIL population, a QTL, denoted by qQTF-3-3, was detected, explaining 25.3% of the variation in folate content. All the positive alleles for higher folate content were from the high-folate parents, i.e., Teqing and Kasalath. The known putative folate biosynthesis genes do not underlie the QTLs detected in this study and therefore may be novel loci affecting folate content in milled rice. QTLs identified in this study have potential value for marker assisted breeding for high-folate rice variety.
    QTL Mapping for Important Agronomic Traits in Synthetic Hexaploid Wheat Derived from Aegiliops tauschii ssp. tauschii
    YU Ma, CHEN Guo-yue, ZHANG Lian-quan, LIU Ya-xi, LIU Deng-cai, WANG Ji-rui, PU Zhien, ZHANG Li, LAN Xiu-jin, WEI Yu-ming, LIU Chun-ji , ZHENG You-liang
    2014, 13(8): 1835-1844.  DOI: 10.1016/S2095-3119(13)60655-3
    Abstract ( )   PDF in ScienceDirect  
    Aegiliops tauschii is classified into two subspecies: Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype (SHW-L1) by crossing an Ae. tauschii ssp. tauschii accession (AS60) with a tetraploid wheat genotype (AS2255). A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.
    Molecular Diversity and Association Analysis of Drought and Salt Tolerance in Gossypium hirsutum L. Germplasm
    JIA Yin-hua, SUN Jun-ling, WANG Xi-wen, ZHOU Zhong-li, PAN Zao-e, HE Shou-pu, PANG Bao-yin, WANG Li-ru , DU Xiong-ming
    2014, 13(8): 1845-1853.  DOI: 10.1016/S2095-3119(13)60668-1
    Abstract ( )   PDF in ScienceDirect  
    Association mapping is a useful tool for the detection of genes selected during plant domestication based on their linkage disequilibrium (LD). This study was carried out to estimate genetic diversity, population structure and the extent of LD to develop an association framework in order to identify genetic variations associated with drought and salt tolerance traits. 106 microsatellite marker primer pairs were used in 323 Gossypium hirsutum germplasms which were grown in the drought shed and salt pond for evaluation. Polymorphism (PIC=0.53) was found, and three groups were detected (K=3) with the second likelihood ΔK using STRUCTURE software. LD decay rates were estimated to be 13-15 cM at r2 0.20. Significant associations between polymorphic markers and drought and salt tolerance traits were observed using the general linear model (GLM) and mixed linear model (MLM) (P 0.01). The results also demonstrated that association mapping within the population structure as well as stratification existing in cotton germplasm resources could complement and enhance quantitative trait loci (QTLs) information for marker-assisted selection.
    A Dominant Locus, qBSC-1, Controls β Subunit Content of Seed Storage Protein in Soybean (Glycine max (L.) Merri.)
    WANG Jun, LIU Lin, GUO Yong, WANG Yong-hui, ZHANG Le, JIN Long-guo, GUAN Rong-xia, LIU Zhang-xiong, WANG Lin-lin, CHANG Ru-zhen , QIU Li-juan
    2014, 13(9): 1854-1864.  DOI: 10.1016/S2095-3119(13)60579-1
    Abstract ( )   PDF in ScienceDirect  
    Soybean seed storage protein is one of the most important plant vegetable proteins, and β subunit is of great significance to enhance soybean protein quality and processing property. F2 segregated population and residual heterozygous lines (RHL) derived from the cross between Yangyandou (low level of β subunit) and Zhonghuang 13 (normal level of β subunit) were used for mapping of β subunit content. Our results showed that β subunit content was controlled by a single dominant locus, qBSC-1 (β subunit content), which was mapped to a region of 11.9 cM on chromosome 20 in F2 population of 85 individuals. This region was narrowed down to 2.5 cM between BARCSOYSSR_20_0997 and BARCSOYSSR_20_0910 in RHL with a larger population size of 246 individuals. There were 48 predicted genes within qBSC-1 region based on the reference genome (Glyma 1.0, Williams 82), including the two copies of β subunit coding gene CG4. An InDel marker developed from a thymine (TT) insertion in one copy of CG4 promoter region in Yangyandou cosegregrated with BARCSOYSSR_20_0975 within qBSC-1 region, suggesting that this InDel marker maybe useful for marker-assisted selection (MAS).
    Characterization of Genomic Integration and Transgene Organization in Six Transgenic Rapeseed Events
    WU Yu-hua, ZHANG Li, WU Gang, NIE Shu-jing , LU Chang-ming
    2014, 13(9): 1865-1876.  DOI: 10.1016/S2095-3119(13)60628-0
    Abstract ( )   PDF in ScienceDirect  
    To characterize the DNA rearrangement of both the T-DNA region and the genomic insertion site during T-DNA insertion, the Genomewalker strategy was used to isolate the junctions between the inserted DNA and the plant genomic DNA in six rapeseed events as well as the genomic DNA at the sites before integration. During transformation in each of the six events, portions of both the right border (RB) and left border (LB) regions of the T-DNA were deleted, ranging from a 7 nucleotide deletion of the LB repeats in event RF1 to a 207 bp deletion of the LB region in event RF2. For the six events, T-DNA integration resulted in a deletion at the target site spanning less than 100 bp. Sequence analysis indicated that the T-DNA was integrated into the coding region of various native rapeseed genes in events RF1 and RF2. Duplications of the genomic DNA target site were observed in events RF2, RF3 and Topas 19/2. And multimerization of transgenes was found in event Topas 19/2, in which, the T-DNA was integrated as a head-to-head (RB-to-RB) concatemer into the recipient genome. In event MS1, chromosomal translocation or a large target-site deletion may have occurred during T-DNA integration, which was identified due to a failure to amplify the presumptive insertion site based on the flanking rapeseed DNA sequences. Our results provide comprehensive data concerning transgene organization and the genomic context of the T-DNA in six rapeseed events, which can aid in the developing of insert fingerprinting and the monitoring of long-term genetic stability and potential unintended effects of transgenic events.
    Molecular Characterization and Expression Profiles of Myrosinase Gene (RsMyr2) in Radish (Raphanus sativus L.)
    PAN Yan1, XU Yuan-yuan1, ZHU Xian-wen2, LIU Zhe1, GONG Yi-qin1, XU Liang1, GONG Mao-yong1, and LIU Li-wang1
    2014, 13(9): 1877-1888.  DOI: 10.1016/S2095-3119(13)60644-9
    Abstract ( )   PDF in ScienceDirect  
    Myrosinase is a defense-related enzyme and is capable of hydrolyzing glucosinolates into a variety of compounds, some of which are toxic to pathogens and herbivores. Many studies revealed that a number of important vegetables or oil crops contain the myrosinase-glucosinolate system. However, the related promoter and genomic DNA sequences as well as expression profiles of myrosinase gene remain largely unexplored in radish (Raphanus sativus). In this study, the 2 798 bp genomic DNA sequence, designated as RsMyr2, was isolated and analyzed in radish. The RsMyr2 consisting of 12 exons and 11 introns reflected the common gene structure of myrosinases. Using the genomic DNA walking approach, the 5´-flanking region upstream of RsMyr2 with length of 1 711 bp was successfully isolated. PLACE and PlantCARE analyses revealed that this upstream region could be the promoter of RsMyr2, which contained several basic cis-regulatory elements including TATA-box, CAAT-box and regulatory motifs responsive to defense and stresses. Furthermore, recombinant pET-RsMyr2 protein separated by SDS-PAGE was identified as myrosinase with mass spectrometry. Real-time PCR analysis showed differential expression profiles of RsMyr2 in leaf, stem and root at different developmental stages (e.g., higher expression in leaf at cotyledon stage and lower in flesh root at mature stage). Additionally, the RsMyr2 gene exhibited up-regulated expression when treated with abscisic acid (ABA), methyl jasmonate (MeJA) and hydrogen peroxide (H2O2), whereas it was down-regulated by wounding (WO) treatment. The findings indicated that the expression of RsMyr2 gene was differentially regulated by these stress treatments. These results could provide new insight into elucidating the molecular characterization and biological function of myrosinase in radish.
    Interactive Effects of Silicon and Potassium Nitrate in Improving Salt Tolerance of Wheat
    Ahmad Bybordi
    2014, 13(9): 1889-1899.  DOI: 10.1016/S2095-3119(13)60639-5
    Abstract ( )   PDF in ScienceDirect  
    Adequate regulation of mineral nutrients might be effective to ameliorate the deleterious effects of salts and help to sustain crop productivity, particularly in glycophytes, under salt stress. In this study, laboratory and greenhouse experiments were carried out at Agricultural and Natural Resources Research Centre in East Azerbaijan, Iran, to investigate the interactive effects of silicon and potassium nitrate in alleviating NaCl induced injuries in wheat (Triticum aestivum L.). In the laboratory experiment, three winter wheat cultivars Pishgam, Afagh and Alvand were grown on sterile filter paper moistened with 20, 40, 60, 80, and 100 mmol L-1 NaCl solution. Results revealed that wheat cultivars were significantly different in their growth response to different concentrations of NaCl and Pishgam was found to be the most tolerant to NaCl stress, and used in the second part of study. In the greenhouse experiment, Pishgam was grown in a hydroponic system subjected to different NaCl levels (20, 60 and 100 mmol L-1) and treated by silicon (0, 2 and 4 mmol L-1, final concentration in nutrient solution using K2SiO3) and potassium nitrate (0, 0.5, 1, and 2 mmol L-1, foliar application). The experimental design was factorial based on a completely randomized design with three replications. It was found that NaCl stress significantly increased proline accumulation and sodium content in the plant tissues while decreased potassium uptake and accumulation by plants. Moreover, plant weight, 100-seed weight, relative water content, chlorophyll content, and photosynthesis were also significantly affected by varying levels of NaCl. However, exogenous application of silicon and potassium nitrate reduced sodium uptake, increased potassium and consequently improved plant weight, 100-seed weight, seed yield, ear length, and photosynthesis rate. This study suggested that utilization of the salt-tolerant cultivar (Pishgam) combined with proper foliar application of potassium nitrate (2 mmol L-1) and silicon (4 mmol L-1) at the wheat booting stage might be a promising approach to obtain higher grain yield on saline lands.
    Transcriptional Regulation of Expression of the Maize Aldehyde Dehydrogenase 7 Gene (ZmALDH7B6) in Response to Abiotic Stresses
    AN Xia, DUAN Feng-ying, GUO Song, CHEN Fan-jun, YUAN Li-xing , GU Ri-liang
    2014, 13(9): 1900-1908.  DOI: 10.1016/S2095-3119(13)60518-3
    Abstract ( )   PDF in ScienceDirect  
    Aldehyde dehydrogenases (ALDHs) represent a large protein family, which includes several members that catalyze the oxidation of an aldehyde to its corresponding carboxylic acid in plants. Genes encoding members of the ALDH7 subfamily have been suggested to play important roles in various stress adaptations in plants. In this study, quantitative RT-PCR analysis revealed that a maize ALDH7 subfamily member (ZmALDH7B6) was constitutively expressed in various organs, including roots, leaves, immature ears, tassels, and developing seeds. The abundance of ZmALDH7B6 mRNA transcripts in maize roots was increased by ammonium, NaCl, and mannitol treatments. To further analyze tissue-specific and stress-induced expression patterns, the 1.5-kb 5´-flanking ZmALDH7B6 promoter region was fused to the β-glucuronidase (GUS) reporter gene and introduced into maize plants. In roots of independent transgenic lines, there was significant induction of GUS activity in response to ammonium supply, confirming ammonium-dependent expression of ZmALDH7B6 at the transcript level. Histochemical staining showed that GUS activity driven by the ZmALDH7B6 promoter was mainly localized in the vascular tissues of maize roots. These results suggested that ZmALDH7B6 is induced by multiple environmental stresses in maize roots, and may play a role in detoxifying aldehydes, particularly in vascular tissue.
    Comparisons of Photosynthetic Characteristics in Relation to Lint Yield Among F1 Hybrids, Their F2 Descendants and Parental Lines of Cotton
    FENG Guo-yi1, 2 , GAN Xiu-xia1, YAO Yan-di1, LUO Hong-hai1, ZHANG Ya-li1 and ZHANG Wangfeng1
    2014, 13(9): 1909-1920.  DOI: 10.1016/S2095-3119(13)60690-5
    Abstract ( )   PDF in ScienceDirect  
    We compared the photosynthetic characteristics in relation to yield of two F1 cotton hybrids (Shiza 2-F1 and Xinluzao 43-F1), their parental lines (NT2, H2 and 4-14) and their F2 descendants at different growth and development stages. The two F1 exhibited heterobeltiosis in net photosynthetic rate (Pn) by 8.1-52.1%, canopy apparent photosynthetic rate (CAP) by 8.2-57.6% and canopy respiration rate (CR) by 3.0-78.7% during the growing season. They also exhibited mid-parent heterosis by 2.0-5.2% in leaf chlorophyll content (SPAD) during the late growth and development stages. Regression analysis showed that both parents contributed to increase in Pn, SPAD and CAP in the F1. A low CR in the F1 matched a low CR of the parental line. Photosynthetic characteristics in the F2 were mainly dependent upon the magnitude and degeneration rate of the F1. Mid-parent heterosis in CAP and in CR during the late growth and development stage reduced the degeneration of the F2. Average dry matter accumulation was 10.7-34.7% higher in the parental lines of Xinluzao 43-F1 than in the parental lines of Shiza 2-F1. Heterobeltiosis in dry matter accumulation was 7.0-23.1% greater for Xinluzao 43-F1 than for Shiza 2-F1. Dry matter accumulation in the F1 was affected by either the dry matter accumulation of parents or heterobeltiosis. Dry matter accumulation in the F2 was mainly influenced by dry matter accumulation in the F1. The yields of the two F1 were 39.1-46.3% higher than their respective parents and 26.4-45.9% higher than that of the conventional cultivar Xinluzao 33. The yields of the two F2 were 9.2-12.8% higher than the parents and 14.9-27.4% higher than that of Xinluzao 33. The photosynthetic production and yield of the F1 and F2 were higher than that of their parents. The increases in Pn and CAP of the F1 and F2 were dependent on the photosynthetic characteristics of their parents. It is thus concluded that the photosynthetic performance, light use efficiency and yield of the F1 can be improved by using at least one parent with low CR, but high CAP, Pn and SPAD. This strategy might also improve the value of the F2.
    Genetics& Breeding· Germplasm Resources · Molecular Genetics
    The Application of GGE Biplot Analysis for Evaluat ng Test Locations and Mega-Environment Investigation of Cotton Regional Trials
    XU Nai-yin, Fok Michel, ZHANG Guo-wei, LI Jian , ZHOU Zhi-guo
    2014, 13(9): 1921-1933.  DOI: 10.1016/S2095-3119(13)60656-5
    Abstract ( )   PDF in ScienceDirect  
    In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction (GGE) biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley (YaRV), China. Four traits (cotton lint yield, fiber length, lint breaking tenacity, micronaire) and two composite selection indices were considered. It was found that the assumption of a single mega-environment in the YaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments: a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identification of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, Sichuan Province, China, was found to be desirable for none.
    Differences in the Efficiency of Potassium (K) Uptake and Use in Five Apple Rootstock Genotypes
    CHANG Cong, LI Chao, LI Cui-ying, KANG Xiao-yu, ZOU Yang-jun , MA Feng-wang
    2014, 13(9): 1934-1942.  DOI: 10.1016/S2095-3119(14)60839-X
    Abstract ( )   PDF in ScienceDirect  
    Plants that grow well while accumulating and transporting less potassium (K) perform better than more-sensitive plants when under deficiency conditions, which makes low-K-input and environmentally friendly agriculture possible. We conducted hydroponics and sand culture experiments to evaluate the efficiency of various apple (Malus domestica Borkh) rootstocks in their K uptake and utilization. Five genotypes were selected which are widely used in China -M. hupehensis Rehd, M. prunifolia Borkh, M. robusta Rehd, M. sieversii Roem, and M. rockii Rehd. Plant heights, root and shoot dry weights, and K concentrations were recorded. These genotypes differed markedly in dry weights, absolute and relative K concentrations, absolute and relative K accumulations, and their K efficiency ratio under deficient K conditions. The last parameter, expressed as relative shoot dry weight, was strongly and positively correlated with the other four parameters in each genotype. Therefore, we suggest that this parameter could serve as an index when selecting K-efficient genotypes. In this study, we have determined that M. sieversii and M. rockii are K-inefficient genotypes; M. prunifolia is K-efficient genotype; M. hupehensis and M. robusta have moderate levels of potassium efficiency.
    Plant Protection
    Highly Sensitive and Specific Monoclonal Antibody-Based Serological Methods for Rice Ragged Stunt Virus Detection in Rice Plants and Rice Brown Planthopper Vectors
    LIU Huan, SONG Xi-jiao, NI Yue-qun, LU Li-na, ZHOU Xue-ping , WU Jian-xiang
    2014, 13(9): 1943-1951.  DOI: 10.1016/S2095-3119(13)60533-X
    Abstract ( )   PDF in ScienceDirect  
    Rice ragged stunt virus (RRSV) is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein (CP) gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21 (DE3) using the pMAL-C2X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody (MAb) against RRSV was obtained by fusing mouse myeloma cells (Sp 2/0) with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay (ACP-ELISA), a dot enzyme-linked immunosorbent assay (dot-ELISA), and immunocapture-RT-PCR (IC-RT-PCR) assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1:40 960, 1:1280 and 1:655360 (w/v, g mL-1), respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1:12800 and 1:1600 (an individual planthopper μL-1), respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.
    Population Genetic Analysis of Blumeria graminis f. sp. tritici in Qinghai Province, China
    XU Zhi, DUAN Xia-yu, ZHOU Yi-lin, GUO Qing-yun, YAO Qiang , CAO Shi-qin
    2014, 13(9): 1952-1961.  DOI: 10.1016/S2095-3119(13)60591-2
    Abstract ( )   PDF in ScienceDirect  
    To gain more precise information about molecular genetic variation for wild populations of Blumeria graminis f. sp. tritici from Qinghai Province, China, 38 single-colony isolates were purified from samples collected from Haidong District, Xining City and Hainan Tibetan Autonomous Prefecture in 2010. The virulence of 21 isolates among them was tested at seedling stage on 34 wheat cultivars (lines) carrying known powdery mildew (Pm) resistant genes. The results showed that V1a, V3a, V3c, V3e, V5a, V6, V7, V8 and V19 had high virulence frequencies (>75%), indicating a wide distribution; and V1c, V5b, V12, V13, V16, V21, VXBD, V2+6, V2+Mld and V4+8, with less distribution, appeared to be lower in frequencies (0-20%). The Nei’s gene diversity (H), Shannon’s information index (I) and the percentage of polymorphic loci (P) were 0.23, 0.35 and 67.65%, respectively, which revealed a virulent diversity. The results from single nucleotide polymorphisms (SNPs) of 38 isolates showed that three housekeeping genes were found to contain a total of 9 SNP sites. 10 haplotypes (H1-H10) were inferred from the concatenated sequences, with 1 haplotype (H1) comprising of over 55% of Qinghai population. Phylogenic analysis did not show obvious geographical subdivision between the isolates. A multilocus haplotype network presented a radial structure, with H1 in the central as an inferred ancestor. Using analysis of molecular variance (AMOVA), we found 1.63% of the total variation was among populations and 98.37% within populations, with a low fixations index (FST=0.01634, P<0.05). This revealed a relatively high genetic diversity but a low genetic divergence in Qinghai population. Moreover, the molecular data on gene flow (Nm=6.32) confirmed the migration of pathogen populations among areas in Qinghai Province.
    Changes in Soil Biota Resulting from Growth of the Invasive Weed, Ambrosia artemisiifolia L. (Compositae), Enhance Its Success and Reduce Growth of Co-Occurring Plants
    LI Hui-na, XIAO Bo, LIU Wan-xue , WAN Fang-hao
    2014, 13(9): 1962-1971.  DOI: 10.1016/S2095-3119(13)60569-9
    Abstract ( )   PDF in ScienceDirect  
    Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites (heavily invaded and newly invaded) than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants (Galinsoga parviflora Cav., Medicago sativa L. and Setaria plicata (Lam.) T. Cooke.) compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only (invasion by A. artemisiifolia alone), in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion alters the soil microbial community in a way that favors itself while inhibiting native plant species, with measurable effects on performance of co-occurring plants.
    Molecular Characterization and Functional Analysis of Krüppel-homolog 1 (Kr-h1) in the Brown Planthopper, Nilaparvata lugens (Stål)
    JIN Min-na, XUE Jian, YAO Yun , LIN Xin-da
    2014, 13(9): 1972-1981.  DOI: 10.1016/S2095-3119(13)60654-1
    Abstract ( )   PDF in ScienceDirect  
    The brown planthopper, Nilaparvata lugens (Stål), is the most serious insect pest of rice. It has developed high resistance to traditional insecticides because of their intensive use. Juvenile hormone (JH) analogs have been used successfully to control this species and other pest insects. However, the molecular mechanism of JH signaling is not well understood. Krüppel-homolog 1 (Kr-h1) is a transcription factor involved in the JH pathway. In this study, the Kr-h1 cDNA was cloned and characterized from N. lugens by rapid amplification of cDNA ends (RACE) and reverse transcription PCR (RT-PCR). Its spatial and temporal expression profiles were examined by real-time quantitative PCR, and its function was also studied by RNA interference (RNAi). The open reading frame of NlKr-h1 is 1 833 bp encoding for 611 amino acids. The protein contains eight conserved zinc-finger motifs. NlKr-h1 was expressed at all life stages, with the highest mRNA level in the 4-day embryo. NlKr-h1 mRNA levels rose during each nymphal molt after the 2nd instar. In the adults, the mRNA level in males was significantly higher than that in females of either the macropterous or brachypterous type. The highest expression was observed in the female midgut. NlKr-h1 was activated by juvenile hormone III (JH III) in the 3rd-5th instar nymphs. Disruption of Nlkr-h1 expression by RNAi caused stunted wing development and malformations of both male and female external genitalia. Our findings suggest that Kr-h1 may be a useful target for pest insect management.
    Molecular Taxonomy of Conogethes punctiferalis and Conogethes pinicolalis (Lepidoptera: Crambidae) Based on Mitochondrial DNA Sequences
    WANG Jing, ZHANG Tian-tao, WANG Zhen-ying, HE Kang-lai, LIU Yong , LI Jing
    2014, 13(9): 1982-1989.  DOI: 10.1016/S2095-3119(13)60678-4
    Abstract ( )   PDF in ScienceDirect  
    Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae) was originally considered as one species with fruit-feeding type (FFT) and pinaceae-feeding type (PFT), but it has subsequently been divided into two different species of Conogethes punctiferalis and Conogethes pinicolalis. The relationship between the two species was investigated by phylogenetic reconstruction using maximum-likelihood (ML) parameter estimations. The phylogenetic tree and network were constructed based upon sequence data from concatenation of three genes of mitochondrial cytochrome c oxidase subunits I, II and cytochrome b which were derived from 118 samples of C. punctiferalis and 24 samples of C. pinicolalis. The phylogenetic tree and network showed that conspecific sequences were clustering together despite intraspecific variability. Here we report the results of a combined analysis of mitochondrial DNA sequences from three genes and morphological data representing powerful evidence that C. pinicolalis and C. punctiferalis are significantly different.
    Animal Science · Veterinary Science
    Genetic Variation of EPAS1 Gene in Tibetan Pigs and Three Low-Altitude Pig Breeds in China
    DONG Kun-zhe, KANG Ye, YAO Na, SHU Guo-tao, ZUO Qing-qing, ZHAO Qian-jun , MA Yue-hui
    2014, 13(9): 1990-1998.  DOI: 10.1016/S2095-3119(13)60577-8
    Abstract ( )   PDF in ScienceDirect  
    Endothelial PAS domain protein 1 (EPAS1), also called hypoxia-inducible factor-2, is a key regulatory factor of hypoxic responses and plays an essential role in high-altitude adaptation in mammalian species. In this study, polymorphisms of EPAS1 were detected in 217 individuals from 2 Tibetan pig populations and 3 low-altitude pig breeds by DNA pooling, PCR-SSCP, PCR-RFLP and DNA sequencing methods. A total of 14 synonymous polymorphisms were identified in the coding region. The analysis suggested that SNP1 (G963A), SNP7 (C1632T), SNP10 (G1929A) and SNP11 (G1947A) showed potential association with high-altitude environment because of their particular variation patterns in Tibetan pigs. Linkage disequilibrium (LD) of these SNPs was analyzed. One common LD block including 5 SNPs clustering in exon 12 was identified in all studied pig populations. Haplotype H1 (AGGTC) in LD block was dominant in Tibetan pigs (76.6 and 74.2% in Linzhi (LZ) and Chayu (CY) pigs, respectively) and segregated at higher frequency than that in low-altitude pig breeds (52.3, 58.7 and 56.2% in Wuzhishan (WZS), Min (M) and Laiwu (LW) pigs, respectively), indicating that H1 may relate to adaptation to high altitude in Tibetan pigs. These findings raise hope that EPAS1 gene can be a candidate gene that involved in adaptation of high altitude in Tibetan pigs.
    Mapping QTLs Affecting Economic Traits on BTA3 in Chinese Holstein with Microsatellite Markers
    QIN Chun-hua, CHU Qin, CHU Gui-yan, ZHANG Yi, ZHANG Qin, ZHANG Sheng-li , SUN Dong-xiao
    2014, 13(9): 1999-2004.  DOI: 10.1016/S2095-3119(13)60616-4
    Abstract ( )   PDF in ScienceDirect  
    It had been demonstrated that the strong and highly significant quantitative trait locus (QTL) can affect protein percentage on Bos Taurus Autosome 3 (BTA3) at the position 52 cM, near the microsatellite DIK4353, with the 95% confidence interval spanning from 25 to 57 cM in Chinese Holstein population using QTL-express, MQREML, and GRIDQTL softwares. This study herein focused on such region of fine mapping QTLs for milk production and functional traits with 16 microsatellite markers with coverage of 33 cM between the markers BMS2904 and MB099 on BTA3 in a daughter-designed Chinese Holstein population. A total of 1 298 Holstein cows and 7 sires were genotyped for 16 microsatellites with ABI 3700 DNA sequencer. The variance components QTL linkage analysis (LA) and linkage-disequilibrium (LD) analysis (LA/LD) was performed to map QTLs for 7 traits, i.e., 305-d milk yield, fat yield, protein yield, fat percentage, protein percentage, somatic cell score and persistency of milk yield. Four strong and highly significant QTLs were detected for fat yield, fat percentage, protein percentage and somatic cell score at the position 40, 30, 27 and 26 cM, respectively. Two minor QTLs for milk yield and persistency of milk yield were identified at 42 and 46 cM, respectively. These findings provided a general idea for the fine mapping of the causal mutation for milk production and functional traits on BTA3 in the future.
    Promotion and Inhibition of Ruminal Epithelium Growth by Butyric Acid and Insulin-Like Growth Factor-1 (IGF-1) in Dairy Goats
    LIU Da-cheng, ZHOU Xiang-li, LIU Guo-juan, GAO Min , HU Hong-lian
    2014, 13(9): 2005-2009.  DOI: 10.1016/S2095-3119(13)60603-6
    Abstract ( )   PDF in ScienceDirect  
    Isolated ruminal epithelia from caudal blind sacs of dairy goats were incubated with butyrate and insulin-like growth factor-1 (IGF-1) at different concentrations. Proportions of ruminal epithelium in different phases of the cell division cycle were determined by flow cytometric analysis. The proportion of epithelial cells in S phase and G2-M phase (PS&G2-M) increased significantly (P<0.01) whereas the proportion of epithelial cells in G0-G1 phase (PG0-G1) decreased after incubation with IGF-1. PS&G2-M decreased whereas PG0-G1 increased markedly (P<0.01) after incubation with sodium butyrate. PS&G2-M incubated with IGF-1 and butyrate sodium together increased more than that incubated with IGF-1 alone; PG0-G1, however, decreased significantly (P<0.01). Our results indicate that IGF-1 enhances whereas sodium butyrate inhibits the proliferation of rumen epithelial cells. Furthermore, butyrate and IGF-1, together, have a synergic effect on the proliferation of rumen epithelium.
    Immunoproteomic Analysis of Bordetella bronchiseptica Outer Membrane Proteins and Identification of New Immunogenic Proteins
    LIU Yan, QIN Feng-yan, BAO Guo-lian, CHEN Hui, XIAO Chen-wen, WEI Qiang , JI Quan-an
    2014, 13(9): 2010-2018.  DOI: 10.1016/S2095-3119(13)60618-8
    Abstract ( )   PDF in ScienceDirect  
    Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchiseptica, immunoproteomic analysis was adopted to analyse outer membrane proteins of it. The outer membrane proteins extracted from B. bronchiseptica were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the convalescent serum against two strains. Immunogenic proteins were identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF-MS), a total of 14 proteins are common immunoreactive proteins, of which 1 was known antigen and 13 were novel immunogenic proteins for B. bronchiseptica. Putative lipoprotein gene was cloned and recombinantly expressed. The recombinant protein induced high titer antibody, but showed low protective indices against challenges with HB (B. bronchiseptica strain isolated from a infected rabbit). The mortality of mice was 80% compared to 100% of positive controls. The identification of these novel antigenic proteins is an important resource for further development of a new diagnostic test and vaccine for B. bronchiseptica.
    Protective Effect of Wheat Peptides Against Small Intestinal Damage Induced by Non-Steroidal Anti-Inflammatory Drugs in Rats
    YIN Hong, PAN Xing-chang, WANG Shao-kang, YANG Li-gang , SUN Gui-ju
    2014, 13(9): 2019-2027.  DOI: 10.1016/S2095-3119(13)60619-X
    Abstract ( )   PDF in ScienceDirect  
    Non-steroidal anti-inflammatory drugs (NSAIDs) were able to produce tissue damage and oxidative stress in animal models of small intestinal damage. In this study, the putative protective effect of wheat peptides was evaluated in a NSAID-induced small intestinal damage model in rats, different doses of wheat peptides or distilled water were administered daily by intragastric administration for 30 d until small intestinal damage was caused. Before sacrificing, NSAIDs (aspirin and indomethacin) or physiological saline were infused into the digestive tract twice. Wheat peptides administration reduced edema and small intestinal damage, and significantly decreased the level of tumor necrosis factor (TNF)-α in mucous membrane of small intestine. Oxidative stress was significantly increased after NSAID infusion and was reduced by wheat peptides. Wheat peptides increased glutathione peroxidase (GSH-Px) activity in mucous membrane of small intestine. μ-Opioid receptor mRNA expression decreased more significantly in wheat peptides treated rats than in the model control group. Overall, the results suggest that non-steroidal anti-inflammatory drugs induced small intestinal damage in rats and wheat peptides administration may be an effective tool for protecting small intestinal tissue against NSAID-induced small intestinal damage and oxidative stress.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Effects of Phosphorus Application in Different Soil Layers on Root Growth, Yield, and Water-Use Efficiency of Winter Wheat Grown Under Semi-Arid Conditions
    KANG Li-yun, YUE Shan-chao , LI Shi-qing
    2014, 13(9): 2028-2039.  DOI: 10.1016/S2095-3119(14)60751-6
    Abstract ( )   PDF in ScienceDirect  
    Deep phosphorus application can be a usefull measure to improve crops’ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus (P) application at different soil layers on root growth, grain yield, and water-use efficiency (WUE) of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars: one drought-sensitive (Xiaoyan 22, XY22) and one drought-tolerant (Changhan 58, CH58). The four P treatments were no P (control, CK), surface P (SP), deep P (DP), and deep-band P application (DBP). CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments (DP and DBP) than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight (RW) and root length (RL) in deep soil layer (30-100 cm) were closely positively correlated with grain yield and WUE of CH58 (but not XY22), highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars (r=0.94, P<0.001). In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.
    Nitrogen Mineralization from Animal Manures and Its Relation to Organic N Fractions
    LI Ling-ling , LI Shu-tian
    2014, 13(9): 2040-2048.  DOI: 10.1016/S2095-3119(14)60769-3
    Abstract ( )   PDF in ScienceDirect  
    Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures (3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant (P<0.01 or P<0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.
    Effects of Chlorination on Soil Chemical Properties and Nitrogen Uptake for Tomato Drip Irrigated with Secondary Sewage Effluent
    LI Yan-feng, LI Jiu-sheng, ZHANG Hang
    2014, 13(9): 2049-2060.  DOI: 10.1016/S2095-3119(13)60692-9
    Abstract ( )   PDF in ScienceDirect  
    Chlorination is usually an economical method for treating clogging in drip emitters during sewage application. Appropriate assessment of the responses of soil and crop is essential for determining an optimal chlorination scheme. During 2008 to 2009, field experiments were conducted in a solar-heated greenhouse for tomato drip irrigated with secondary sewage effluent, to investigate the influences of chlorine injection intervals and levels on soil chemical properties and nitrogen uptake. Injection intervals ranging from two to eight weeks and injection concentrations ranging from 2 to 50 mg L-1 were used. A salinity factor and a nutrient factor were extracted from the pool of the nine soil chemical constituents using factor analysis method. The results demonstrated that chlorination practices increased the residual Cl in the soil, resulting in an increased salinity factor, especially for the frequent chlorination at a high injection concentration. Chlorination weakened the accumulation of nutrients factor in the upper soil layer. Nitrogen uptake of the tomato plants also was inhibited by the increased salinity in the upper soil layer caused by high chlorination levels. In order to reduce the unfavorable effect on soil chemical properties and nitrogen uptake, chlorination scheme with concentrations of lower than 20 mg L-1 was recommended.