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    Crop Genetics · Breeding · Germplasm Resources
    Genetic Diversity and Structure of New Inbred Rice Cultivars in China
    XU Qun, CHEN Hong, WANG Cai-hong, YU Han-yong, YUAN Xiao-ping, WANG Yi-ping, FENG Yue, TANG Sheng-xiang, WEI Xing-hua
    2012, 12(10): 1567-1573.  DOI: 10.1016/S1671-2927(00)8689
    Abstract ( )   PDF in ScienceDirect  
    A total of 408 inbred rice cultivars bred in the last decade were analyzed for 24 SSR markers. The results showed the genetic diversity of indica cultivars was higher than that of japonica cultivars, and the genetic diversity of new cultivars raised in recent years was lower. Among the six rice cropping regions (RCRs) in China, genetic diversity was the highest in the central rice region (RCR-II) and the southwest rice region (RCR-III). Genetic differences among subpopulations of japonica were more complex than those in indica. Differentiation among seasonal ecotypes and RCRs in indica populations was unclear, but differentiation between RCR-II and northeast rice region (RCR-V) was more distinct for japonica cultivars. Considering the North rice region (RCR-IV) has very low genetic diversity among the tested cultivars, it is important to broaden the genetic background for future cultivars in rice breeding programs.
    Identification and Gene Mapping of a multi-floret spikelet 1 (mfs1) Mutant Associated with Spikelet Development in Rice
    REN De-yong*, LI Yun-feng*, WANG Zeng, XU Fang-fang, GUO Shuang, ZHAO Fang-ming, SANG Xianchun, LING ing-hua, HE Guang-hua
    2012, 12(10): 1574-1579.  DOI: 10.1016/S1671-2927(00)8690
    Abstract ( )   PDF in ScienceDirect  
    In this study, a rice spikelet mutant, multi-floret spikelet 1 (mfs1), which was derived from ethylmethane sulfonate (EMS)- treated Jinhui 10 (Oryza sativa L. ssp. indica) exhibited pleiotropic defects in spikelet development. The mfs1 spikelet displayed degenerated the empty glume, elongated the rachilla, the extra lemma-like organ and degraded the palea. Additionally, mfs1 flowers produced varied numbers of inner floral organs. The genetic analysis revealed that the mutational trait was controlled by a single recessive gene. With 401 recessive individuals from the F2 segregation population, the MFS1 gene was finally mapped on chromosome 5, an approximate 350 kb region. The present study will be useful for cloning and functional analysis of MFS1, which would facilitate understanding of the molecular mechanism involved in spikelet development in rice.
    Crop Genetics · Breeding · Germplasm Resources
    Isolation and Functional Analysis of the bZIP Transcription Factor Gene TaABP1 from a ChineseWheat Landrace
    CAO Xin-you, CHEN Ming*, XU Zhao-shi, CHEN Yao-feng, LI Lian-cheng, YU Yue-hua, LIU Yangna, MA You-zhi
    2012, 12(10): 1580-1591.  DOI: 10.1016/S1671-2927(00)8691
    Abstract ( )   PDF in ScienceDirect  
    In plants, basic leucine zipper (bZIP) transcription factors play important roles in regulatory processes, including stress response, pathogenic defense and light response as well as organ and tissue differentiation. Chinese wheat landrace Pingyaoxiaobaimai (PYXBM), an original parent of drought tolerant wheat varieties grown in northern China, is significantly tolerant to abiotic stresses such as drought, cold and nutrient deficiencies. In order to isolate key stress-responsive genes and then improve stress tolerances of conventional varieties, a bZIP transcription factor gene was isolated from a cDNA library of drought-treated PYXBM using the in situ plaque hybridization method, and was designated as Triticum aestivum L. abscisic acid (ABA)-responsive element binding protein 1 (TaABP1). It encodes 372 amino acids, and contains three conserved domains (C1-C3) in the N terminal and a bZIP domain in the C terminal which is a typical protein structure for the group member of bZIP family. Transcriptional activation analysis showed that TaABP1 activated the expression of downstream reporter genes in yeast without ABA application. TaABP1 protein fused with green fluorescent protein (GFP) demonstrated that the localization of TaABP1 protein is in the nucleus. Expression pattern assays indicated that TaABP1 was strongly induced by ABA, high salt, low temperature and drought, and its expression was stronger in stems and leaves than in the roots of wheat. Furthermore, overexpression of TaABP1 in tobacco showed significant improvement of drought tolerance. Data suggested that TaABP1 may be a good candidate gene for improving stress tolerance of wheat by genetic transformation and elucidation of the role of this gene will be useful for understanding the mechanism underlying drought tolerance of Chinese wheat landrace PYXBM.
    Isolating the Mutator Transposable Element Insertional Mutant Gene mio16 ofMaize UsingDoubleSelectedAmplification of Insertion Flanking Fragments (DSAIFF)
    ZHONG Wen-juan, ZHANG Mei-dong, YANG Liu-qi, WANG Ming-chun, ZHENG Yong-lian, YANG Wenpeng GAO You-jun
    2012, 12(10): 1592-1600.  DOI: 10.1016/S1671-2927(00)8692
    Abstract ( )   PDF in ScienceDirect  
    Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (mio16) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of mio16. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and mio16 was mapped in silico onto the physical position ranged from 229 965021 to 229 965409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of mio16 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of mio16 is alternated by Mu insertion.
    Analysis of anApplied Core Collection ofAdzuki Bean Germplasm by Using SSR Markers
    WANG Li-xia, CHENG Xu-zhen, WANG Su-hua, TIAN Jing
    2012, 12(10): 1601-1609.  DOI: 10.1016/S1671-2927(00)8693
    Abstract ( )   PDF in ScienceDirect  
    Genetic diversity of 158 accessions of an applied core collection of adzuki bean (Vigna angularis) and 18 wild genotypes were assessed by using 85 microsatellite markers. With an average of 5.81 alleles per locus, 493 alleles were detected, and their distribution frequencies lower than 5% accounted for 73.02% of the total number. The distributions of alleles between the cultivated and the wild adzuki bean germplasm are different, with a higher allelic diversity in the wild germplasm than that of the cultivated ones. An obvious genetic differentiation was also observed between the wild and the cultivated adzuki beans, and SSR markers may be useful in study identification and classification of them. Among cultivated adzuki bean, the genetic similarity coefficient varied from 0.366 to 0.939. Genetic structure analysis can clearly separate the wild genotypes from the cultivated adzuki bean, and also can divide the cultivated ones into different populations, as these populations are closely agreeable with the ecological regions where they originally grow. The results of this study will be useful in arranging local breeding programs, especially in the aspect of parental combinations or identification of progenies. These SSR markers can also provide important information to explain the genetic relationship between the cultivated and wild adzuki beans, and to accelerate the wild gene resources in broadening the gene pool in breeding program.
    Effect ofAscorbic Acid and Silicium on Photosynthesis, Antioxidant Enzyme Activity, and Fatty Acid Contents in Canola Exposure to Salt Stress
    Ahmad Bybordi
    2012, 12(10): 1610-1620.  DOI: 10.1016/S1671-2927(00)8694
    Abstract ( )   PDF in ScienceDirect  
    The effects of exogenous ascorbic acid and silicium on leaf fresh weigh, seed yield, photosynthesis, changes of the activities of major antioxidant enzymes, nitrate reductase activity, proline accumulation, chlorophyll content, and fatty acid composition were investigated in salt-stressed canola. A hydroponic pot experiment was conducted based on randomized complete block design, factorial arrangement was used with 16 combinations of salinity stress (0, 100, 200, and 300 mmol L-1 NaCl), ascorbic acid (0 and 30 mmol L-1), and silicium (2 and 4 mmol L-1 from potassium silicate) with three replicates. The results showed that salinity significantly decreased leaf area and leaf fresh weight, seed yield, photosynthesis, nitrate reductase activity, chlorophyll content, and seed protein percentage. Conversely, respiration, antioxidant enzymes activity, proline accumulation, and linolenic acid percentage increased due to salt stress. Ascorbic acid application improved photosynthesis and seed yield and mitigated antioxidant enzyme activity. In addition, nitrate reductase activity and chlorophyll a and b were positively affected by ascorbic acid. Regarding silicium application, that was found that leaf area, leaf fresh weight, seed yield and photosynthesis, ascorbate peroxidase activity, nitrate reductase activity, and chlorophyll content increased, while respiration decreased. Furthermore, silicium had not significant effect on antioxidant enzyme activity. In general, ascorbic acid and silicium were involved in the defensive mechanisms against salinity stress and it can be suggested that, ascorbic acid and silicium application had positive effect on canola growth under conditions of salt stress.
    Biomass-Based Rice (Oryza sativa L.)AbovegroundArchitectural Parameter Models
    CAO Hong-xin, LIU Yan, LIU Yong-xia, Jim Scott Hanan, YUE Yan-bin, ZHU Da-wei, LU Jian-fei, SUN Jin-ying, SHI Chun-lin, GE Dao-kuo, WEI Xiu-fang, YAO An-qing, TIAN Ping-ping, BAO Tai-lin
    2012, 12(10): 1621-1632.  DOI: 10.1016/S1671-2927(00)8695
    Abstract ( )   PDF in ScienceDirect  
    To quantify the relationships between rice plant architecture parameters and the corresponding organ biomass, and to research on functional structural plant models of rice plant, this paper presented a biomass-based model of aboveground architectural parameters of rice (Oryza sativa L.) in the young seedling stage, designed to explain effects of cultivars and environmental conditions on rice aboveground morphogenesis at the individual leaf level. Various model variables, including biomass of blade and blade length, were parameterized for rice based on data derived from an outdoor experiment with rice cv. Liangyou 108, 86You 8, Nanjing 43, and Yangdao 6. The organ dimensions of rice aboveground were modelled taking corresponding organ biomass as an independent variable. Various variables in rice showed marked consistency in observation and simulation, suggesting possibilities for a general rice architectural model in the young seedling stage. Our descriptive model was suitable for our objective. However, they can set the stage for connection to physiological model via biomass and development of functional structural rice models (FSRM), and start with the localized production and partitioning of assimilates as affected by abiotic growth factors. The finding of biomass-based rice architectural parameter models also can be used in morphological models of blade, sheath, and tiller of the other stages in rice life.
    Effect of Low Light on the Characteristics of Photosynthesis and Chlorophyll a Fluorescence During Leaf Development of Sweet Pepper
    SUI Xiao-lei, MAO Sheng-li, WANG Li-hao, ZHANG Bao-xi, ZHANG Zhen-xian
    2012, 12(10): 1633-1643.  DOI: 10.1016/S1671-2927(00)8696
    Abstract ( )   PDF in ScienceDirect  
    Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY (low light-tolerant genotype) and 20078 (low light-sensitive genotype), were used to study the effects of low light (photosynthetic photon flux density, PPFD was 75- 100 μmol m-2 s-1, control 450-500 μmol m-2 s-1) on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate (PN), photosynthetic apparent quantum efficiency ( i) and carboxylation efficiency (CE) of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point (LCP) decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II (Fv/Fm) was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance ( PS II) was lower accompanied by an increased non-photochemical quenching (NPQ) in young and/or old leaves compared with mature leaves. The antenna thermal dissipation (D) was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy (Ex). Compared with 20078, ShY could maintain higher PN, PS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.
    Hydrogen Sulfide May Function Downstream of Nitric Oxide in Ethylene- Induced Stomatal Closure in Vicia faba L.
    LIU Jing, HOU Zhi-hui, LIU Guo-hua, HOU Li-xia, LIU Xin
    2012, 12(10): 1644-1653.  DOI: 10.1016/S1671-2927(00)8697
    Abstract ( )   PDF in ScienceDirect  
    Pharmacological, laser scanning confocal microscopic (LSCM), and spectrophotographic approaches were used to study the roles of hydrogen sulfide (H2S) and nitric oxide (NO) in signaling transduction of stomatal movement in response to ethylene in Vicia faba L. Ethylene treatment resulted in the dose-dependent stomatal closure under light, and this effect was blocked by the inhibitors of H2S biosynthesis in V. faba L. Additionally, ethylene induces H2S generation and increases L-/D-cysteine desulfhydrase (pyridoxalphosphate-dependent enzyme) activity in leaves of V. faba L. Inhibitors of H2S biosynthesis have no effect on the ethylene-induced stomatal closure, NO accumulation, and nitrate reductase (NR) activity in guard cells or leaves of V. faba L. Moreover, the ethylene-induced increase of H2S levels and L-/Dcysteine desulfhydrase activity declined when NO generation was inhibited. Therefore, we conclude that H2S and NO probably are involved in the signal transduction pathway of ethylene-induced stomatal closure. H2S may represent a novel component downstream of NO in the ethylene-induced stomatal movement in V. faba L.
    Seed Zone Properties and Crop Performance as Affected by Three No-Till Seeders for Permanent Raised Beds in Arid Northwest China
    HE Jin, LI Hong-wen, Allen David McHugh, WANG Qing-jie, LI Hui, Rabi Gautam Rasaily, Khokan Kumer Sarker
    2012, 12(10): 1654-1664.  DOI: 10.1016/S1671-2927(00)8698
    Abstract ( )   PDF in ScienceDirect  
    The no-till seeders of various soil opener configurations have been shown to produce various soil physical responses in relation to soil and climate conditions, thus affecting crop performance in permanent raised beds (PRB) systems. This is particularly important in arid Northwest China where large volumes of residue are retained on the soil surface after harvest. In Zhangye, Gansu Province, China, a field trial assessed the effects of three typical (powered-chopper, powered-cutter and powered-disc) PRB no-till seeders and one traditional seeder on soil disturbance, residue cover index, bulk density, fuel consumption, plant growth, and subsequent yield. In general, seedbed conditions and crop performance for PRB notill seeders seeded plots were better than for traditional seeded plots. In PRB cropping system, the powered-chopper seeder decreased mean soil disturbance and increased residue cover index compared to powered-disc and -cutter seeders. However, the results indicated that soil bulk density was 2.3-4.8% higher, soil temperature was 0.2-0.6°C lower, and spring wheat emergence was 3.2-4.7% less. This was attributed to greater levels of residue cover and firmer seedbeds. Spring maize and wheat performance in the powered-cutter and -disc treatments was better (non-significant) than poweredchopper treatment. So powered disc no-till seeder, which generally provided the best planting condition and the highest yield, appeared to be the suitable seeder in heavy residue cover conditions. Considering the precision requirements for soil disturbance and residue cover, the powered strip-chopping no-till seeder could be a suitable option for PRB cropping system in Northwest China. Although these results are preliminary, they are still valuable for the design and selection of no-till seeders for PRB cropping systems in arid Northwest China.
    Induction of Hypersensitive Response and Nonhost Resistance by a Cladosporium fulvum Elicitor CfHNNI1 is Dose-Dependent and Negatively Regulated by Salicylic Acid
    XU You-ping, CHEN Hui-ying, ZHOU Xin, CAI Xin-zhong
    2012, 12(10): 1665-1674.  DOI: 10.1016/S1671-2927(00)8699
    Abstract ( )   PDF in ScienceDirect  
    Nonhost resistance is a phenomenon that enables plants to protect themselves against the majority of potential pathogens, and thus has a great potential for application in plant protection. We recently found that CfHNNI1 (for Cladosporium fulvum host and nonhost plant necrosis inducer 1) is an inducer of plant hypersensitive response (HR) and nonhost resistance. In this study, its functional mechanism was analyzed. CfHNNI1 was a single copy gene in C. fulvum genome. The functional ORF of the CfHNNI1 cDNA was ATG3-TAG780, which showed homology with genes encoding bZIP transcription factors. The functional ORF included in frame an inner one ATG273-TAG780, which was sufficient to induce HR in plants. CfHNNI1 induced plant HR in a dose-dependent manner. CfHNNI1-induced necrosis in NahG transgenic tomato plants was significantly stronger than that in their wild type controls. However, the necrosis in Nr and def1 tomato mutants was similar to that in their corresponding wild type plants. These data demonstrate that induction of HR and nonhost resistance by CfHNNI1 is negatively regulated by salicylic acid signalling pathway but independent of ethylene and jasmonic acid signalling pathways.
    Interacted Effect of Arbuscular Mycorrhizal Fungi and Polyamines on Root SystemArchitecture of Citrus Seedlings
    WU Qiang-sheng, ZOU Ying-ning, LIU Chun-yan, LU Ting
    2012, 12(10): 1675-1681.  DOI: 10.1016/S1671-2927(00)8700
    Abstract ( )   PDF in ScienceDirect  
    Either arbuscular mycorrhizal fungi (AMF) or polyamines (PAs) may change root system architecture (RSA) of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF (Paraglomus occultum) and exogenous PAs, including putrescine (Put), spermidine (Spd) and spermine (Spm) on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus (Citrus tangerine Hort. ex Tanaka) seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits (taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots) of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd>Spm>Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs (especially Spd) to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth (shoot and root dry weight).
    Omethoate-Induced Changes of (+)-d-Cadinene Synthase Activity and Gossypol Content in Cotton Seedlings
    YANG Wen-ling, SHI Xue-yan, ZHONG Li, LIANG Pei, SONG Dun-lun, GAO Xi-wu
    2012, 12(10): 1682-1690.  DOI: 10.1016/S1671-2927(00)8701
    Abstract ( )   PDF in ScienceDirect  
    The gene expression and activity of (+)-d-cadinene synthase during cotton development and in response to stress, as well as the spatial and temporal pattern of sesquiterpene biosynthesis, constitute one of chemical defense mechanisms in cotton plants. In order to explore the effects of omethoate on the cotton defense in relation to (+)-d-cadinene synthase and gossypol, effects of omethoate treatments on activity of (+)-d-cadinene synthase and gossypol content in cotton seedlings were investigated. Cotton seedlings treated with 400 mg L-1 omethoate exhibited a significant decrease in the specific activity of (+)-d-cadinene synthase from 12 to 120 h after treating when compared to the untreated control; significantly lower (+)-d-cadinene synthase activity was also observed in cotton seedlings treated with 200 mg L-1 omethoate from 72 to 120 h after treating; but for cotton seedlings treated with 100 mg L-1 omethoate, from 12 to 120 h after treating, no significant changes were observed for activity of (+)-d-cadinene synthase. The gossypol content in cotton seedlings treated with 100, 200 or 400 mg L-1 omethoate for different time periods showed no significant changes compared to that of the control. These results indicated that the activity of (+)-d-cadinene synthase in cotton seedlings in responses to exposure of omethoate at three concentrations for different time periods followed dose- and time-dependent responses to omethoate exposure. With omethoate as a chemical stress factor for cotton seedlings, the cotton defense in relation to the activity of (+)-d-cadinene synthase in cotton seedlings may be affected by omethoate application.
    The mRNA Expression and Methylation Status in Imprinting Control Region of H19 Gene Between Cattle-Yak and Their Parents
    LI Ming-gui*, LIU Zhen-shan*, PAN Zeng-xiang, LUO Hua, XIE Zhuang; LI Qi-fa
    2012, 12(10): 1691-1699.  DOI: 10.1016/S1671-2927(00)8702
    Abstract ( )   PDF in ScienceDirect  
    The H19 gene, which is imprinted with preferential expression from the maternal allele, was one of the first identified imprinting genes in mammals. Recent studies revealed that correct imprinting of the H19 gene plays a vital role in human spermatogenesis. To investigate whether imprinting defects were associated with the hybrid sterility of male cattle-yak, the methylation patterns of the H19 imprinting control region (ICR) and H19 mRNA expression in the testes of cattle-yak, yak, and cattle were examined. The results showed that the 3rd CCCTC-binding factor (CTCF) site of the H19 ICR was significantly hypomethylated in the testes of cattle-yak compared with yak or cattle. As expected, H19 was expressed at a significantly higher level in cattle-yak than in yak or cattle. These results suggest that imprinting defects of the CTCFbinding site in the H19 ICR were possibly associated with disturbed spermatogenesis of male cattle-yak. Thus, we propose that disorders in H19 imprinting, resulting in an increased H19 mRNA expression, might contribute to the sterility of F1 male hybrids between cattle and yak.
    The Effect ofAdministration of Rutin on Plasma Levels of Estrogen, Prolactin, Growth Hormone and Gene Expression of Their Receptors in Mammary Glands in Ovariectomized Rats
    GUO Xu-dong, DIAO Qi-yu, WANG Yue-ying, TU Yan, DENG Kai-dong, WANG Xin-jian, FU Tong, YAN Gui-long
    2012, 12(10): 1700-1706.  DOI: 10.1016/S1671-2927(00)8703
    Abstract ( )   PDF in ScienceDirect  
    The development of mammary glands, endocrine hormone concentrations and the gene expression of related receptors were measured in ovariectomized virgin rats after adminstration of an estrogen-like plant extract, rutin. Thirty-two ovariectomized virgin Wistar rats were randomly assigned to 4 treatments with 8 animals each: gastric infusion of 2 mL normal saline per unovariectomized rat per day (Sham), gastric infusion of 2 mL normal saline per ovariectomized rat per day (Ova), gastric infusion of 60 mg rutin kg-1 body weight (BW) per ovariectomized rat per day (Ova+Rut), or intramuscular injection of 60 μg estradiol kg-1 BW per ovariectomized rat weekly (Ova+Est). Samples of blood and mammary glands were harvested to determine the levels of estrogen (E2), prolactin (PRL) and growth hormone (GH), and the gene expression of estrogen receptors (ER), prolactin receptors (PRLR) and growth hormone receptors (GHR) with radioimmunoassy (RIA) and RT-PCR technology, respectively. The E2 concentration in plasma and gland tissues from the rats of Ovx+Rut or Ovx+Est was higher than that of Ovx (P<0.05), but the plasma E2 concentration from the rats of Ovx+Rut was lower than that of Sham (P<0.05). The order of the PRL concentration in plasma and gland tissues was Ovx
    Genomic Analysis of Mitochondrial Carrier Genes in the Bombyx mori
    CAO Jun, SHI Feng
    2012, 12(10): 1707-1713.  DOI: 10.1016/S1671-2927(00)8704
    Abstract ( )   PDF in ScienceDirect  
    This study is performed to investigate the mitochondrial carrier gene family in silkworm genome. In total, 30 genes are identified and claded into eight well-conserved groups. Gene duplication contributes to the expansion and complexity of this family. Diverse expression patterns suggest their functional differentiation. Analyses of the sitespecific profiles reveal critical amino acid residues for functional divergence. This study highlights the molecular evolution of the mitochondrial carrier gene family in silkworm and may provide a starting point for further experimental verification.
    Characterization of blaCTX-M Gene in One Klebsiella pneumoniae Isolate from Sick Chickens in China
    HU Gong-zheng*, HU Han*, LIU Bao-guang*, YUAN Li, LIU Jian-hua, PAN Yu-shan, WU Hua, CHEN Yu-xia
    2012, 12(10): 1714-1720.  DOI: 10.1016/S1671-2927(00)8705
    Abstract ( )   PDF in ScienceDirect  
    Two Klebsiella pneumoniae isolates (Kpc1 and Kpc2) were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A b-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried blaTEM-1 and tet(A) genes. The ESBL-producing strain Kpc1 exhibited multidrug resistant phenotype and harbored blaTEM-1, blaCTX-M-14, tet(A), tet(B), and rmtB genes. K. pneumoniae Kpc1 contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried blaTEM-1 and blaCTX-M-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The blaCTX-M-14 gene was flanked upstream by an ISEcp1 insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The blaCTX-M-14 gene was associated with an upstream ISEcp1 insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type b-lactamase in China.
    Anti-Recombinant Gametocyte 56 Protein IgY Protected Chickens from Homologous Coccidian Infection
    DING Jun, LIU Qiao-rong, HAN Jin-peng, QIAN Wei-feng, LIU Qun
    2012, 12(10): 1721-1728.  DOI: 10.1016/S1671-2927(00)8706
    Abstract ( )   PDF in ScienceDirect  
    Coccidiosis is caused by intra-cellular infection of Eimeria spp., which goes through a complex life cycle in the intestinal mucosa of infected hosts. Specific immunoglobulins (IgY) could be produced in egg yolk by immunizing hens with specific antigens. In the present study, we cloned the E. maxima gam56 gene, expressed the GST-GAM56 fusion protein and raised IgY to GST-GAM56 in hens. The anti-GST-GAM56 IgY antibody was isolated and used to treat chickens infected with E. maxima oocysts. Intramuscular injection of the antibodies provided minimal protection against parasite infection. However, oral dosing of the IgY 3 or 5 d after oocyst inoculation significantly improved body weight gain, reduced oocyst output and intestinal lesion score were reduced at 3 or 5 d after oocyst challenging, compared to the untreated control group. Our findings suggest that the IgY to gam56 could be an effective prophylactic or therapeutic agent against E. maxima infection in chickens and should have a practical application value.
    Geostatistical Assessment of the Spatial Distribution of Some Chemical Properties in Calcareous Soils
    Asma Najafian, Mahmood Dayani, Hamid Reza Motaghian, Habibolah Nadian
    2012, 12(10): 1729-1737.  DOI: 10.1016/S1671-2927(00)8707
    Abstract ( )   PDF in ScienceDirect  
    Spatial patterns of soil fertility parameters and other extrinsic factors need to be identified to develop farming practices that match agricultural inputs with local crop needs. Little is known about the spatial structure of nutrition in Iran. The present study was conducted in a 132-ha field located in central Iran. Soil samples were collected at 0-30 cm depth and were then analyzed for total nitrogen (N), available phosphorus (P), available potassium (K), available copper (Cu), available zinc (Zn), available iron (Fe) and available manganese (Mn). The results showed that the contents of soil organic matter, Cu and Zn in Marvdasht’s farms were low. The spatial distribution model and spatial dependence level for soil chemical properties varied in the field. N, K, carbonate calcium equivalent (CaCO3) and electrical conductivity (EC) data indicated the existence of moderate spatial dependence. The variograms for other variables revealed stronger spatial structure. The results showed a longer range value for available P (480 m), followed by total N (429 m). The value of other chemical properties values showed a shorter range (128 to 174 m). Clear patchy distribution of N, P, K, Fe, Mn, Cu and Zn were found from their spatial distribution maps. This proved that sampling strategy for estimating variability should be adapted to the different soil chemical properties and field management. Therefore, the spatial variability of soil chemical properties with strong spatial dependence could be readily managed and a site-specific fertilization scheme for precision farming could be easily developed.
    VarietalDifferences in PlantGrowth, PhosphorusUptake and Yield Formation in Two Maize Inbred Lines Grown Under Field Conditions
    CHEN Fan-jun, LIU Xiang-sheng, MI Guo-hua
    2012, 12(10): 1738-1743.  DOI: 10.1016/S1671-2927(00)8708
    Abstract ( )   PDF in ScienceDirect  
    Selection for phosphorus (P)-efficient genotypes and investigation of physiological mechanisms for P-use efficiency in maize has mainly been conducted at the seedling stage under controlled greenhouse conditions. Few studies have analyzed characteristics of plant growth and yield formation in response to low-P stress over the whole growth period under field conditions. In the present study, two maize inbred lines with contrasting yield performances under low-P stress in the field were used to compare plant growth, P uptake and translocation, and yield formation. Phosphorus accumulation in the P-efficient line 154 was similar to that of line 153 under high-P. Under low-P, however, P uptake in line 154 was three times greater than that in line 153. Correspondingly, P-efficient line 154 had a significantly higher yield than P-inefficient line 153 under low-P conditions (Olsen-P=1.60 mg kg-1), but not under high-P conditions (Olsen-P=14.98 mg kg-1). The yield difference was mainly due to differences in the number of ears per m2, that is, P-efficient line 154 formed many more ears under low-P conditions than P-inefficient line 153. Ear abortion rate was 53% in the P-inefficient line 153, while in line 154, it was only 30%. Low-P stress reduced leaf appearance, and delayed anthesis and the silking stage, but increased the anthesis-silking interval (ASI) to a similar extent in both lines. The maximum leaf area per plant at silking stage was higher in P-efficient line 154 than in P-inefficient line 153 under both P conditions. It is concluded that low-P stress causes intense intraspecific competition for limited P resources in the field condition which gives rise to plant-toplant non-uniformity, resulting in a higher proportion of barren plants. As soon as an ear was formed in the plant, P in the plant is efficiently reutilized for kernel development.
    Tomato Yield and Quality and Emitter Clogging as Affected by Chlorination Schemes of Drip Irrigation Systems Applying Sewage Effluent
    LI Jiu-sheng, LI Yan-feng, ZHANG Hang
    2012, 12(10): 1744-1754.  DOI: 10.1016/S1671-2927(00)8709
    Abstract ( )   PDF in ScienceDirect  
    Chlorination has been recognized as an efficient and economically favorable method for treating clogging in drip emitters caused by biological growth during sewage application. Further important criteria for determining an optimal chlorination scheme are the different responses of crops to the chloride added into the soil through chlorination. During two seasons in 2008 and 2009, field experiments were conducted in a solar-heated greenhouse with drip irrigation systems applying secondary sewage effluent to tomato plants to investigate the influences of chlorine injection intervals and levels on plant growth, yield, fruit quality, and emitter clogging. Injection intervals ranging from 2 to 8 wk and injection concentrations ranging 2-50 mg L-1 of free chlorine residual at the end of the laterals were used. For the 2008 experiments, the yield from the treatments of sewage application with chlorination was 7.5% lower than the yield from the treatment of sewage application without chlorination, while the yields for the treatments with and without chlorination were similar for the 2009 experiments. The statistical tests indicated that neither the chlorine injection intervals and concentrations nor the interactions between the two significantly influenced plant height, leaf area, or tomato yield for both years. The qualities of the fruit in response to chlorination were parameter-dependent. Chlorination did not significantly influence the quality of ascorbic acid, soluble sugar, or soluble acids, but the interaction between the chlorine injection interval and the chlorine concentration significantly influenced the levels of soluble solids. It was also confirmed that chlorination was an effective method for reducing biological clogging. These results suggested that chlorination is safe for a crop that has a moderate sensitivity to chlorine, like tomato, and can maintain a high level of performance in drip irrigation systems applying sewage effluent