Argonaute （AGO） protein is a highlyconserved family with many members, containing three conserved domains, PAZ，MID and PIWI. Arabidopsis AGO comprises 10 proteins named from AtAGO1 to AtAGO10, which are grouped into three classes with AtAGO1, AtAGO5 and AtAGO10; AtAGO2, AtAGO3 and AtAGO7; and AtAGO4, AtAGO6, AtAGO8 and AtAGO9 as one class respectively. Some members of AGO family proteins have been found to bind small RNAs, which are generated through the function of DCLs, to form a RNAinduced silencing complex (RISC), leading to RNA silencing at either transcriptional or posttranscriptional level, thus results in alternation in development, abiotic and biotic stress resistance. However, the detailed molecular mechanism of AGO function is still largely unknown. To provide some insights into the mechanism of Arabidopsis AGO function, subcellular localization of all Arabidopsis AGO members
was predicted using bioinformatics methods, and that of one member, AtAGO2, was further experimentally identified using a transient GFP reporting system in this study. Finally, effect of jasmonic acid (JA) and benzothiodiazole （BTH）, two wellknown disease resistance regulatory molecules, on subcellular localization of AtAGO2 was examined in order to obtain a hint for possible role of this Arabidopsis AGO in regulation of plant disease resistance. Bioinformatics analyses using Signal P3.0 by algorithm of both Neural networks and Hidden Markov models revealed that all ten AtAGOs did not carry signal peptide, indicating that they were not secretory proteins. Analysis using PredictProtein software showed that AtAGO1, AtAGO2, AtAGO3, AtAGO4 and AtAGO9 contained nuclear localization signals (NLS), although differing in sequence, demonstrating that they might be localized in cell nucleus. To experimentally confirm the bioinformatics prediction, the fulllength cDNA sequence of AtAGO2 was cloned and the expression vector pCHF3eGFP∷AtAGO2 in which AtAGO2 was fused with eGFP reporter gene was constructed to identify the subcellular localization of AtAGO2. AtAGO2 was transiently expressed by Agrobacteriummediated method in leaves of Nicotiana benthamiana. Results of detection of green fluorescence signal by confocal laserscanning microscope showed that AtAGO2 was localized in cytoplasm, plasma membrane and nucleus. Comparative analysis revealed that treatment with 0.2 mmol/L JA, but not 0.38 mmol/L BTH, rendered AtAGO2 was distributed discontinuously in plasma membrane and gathered as bright “granules” in and around plasma membrane. Data in this study revealed that Arabidopsis AGOs were not secretory proteins; AtAGO1, AtAGO3, AtAGO4 and AtAGO9 might be localized in cell nucleus, while AtAGO2 was localized in cytoplasm, plasma membrane and nucleus. Treatment with JA, but not BTH, altered localization of AtAGO2 in plasma membrane and cytoplasm, indicating that AtAGO2 might play a role in regulating disease resistance in JA pathway.

Verticillium wilt, caused by Verticillium dahliae (VD), is the most disastrous pathogen in cotton fungal diseases, which causes huge monetary losses by inducing vascular wilt and exists widely in China cotton planting area. For a long time, scientists are engaged for identifying resistant genes against this pathogen, but can not find any one in tetraploid cotton varieties (Gossypium hirsutum). However, antimicrobial peptide can be chosen as an ideal candidate because of its good features of broadspectrum antibacterial activity，strong thermal stability and immunogenicity，and small molecular weight. Therefore, 20 novel antimicrobial peptides were designed and synthesized to analyze their inhibitory activities against the VD pathogen. After the preliminary screening, 3 peptides (D4E1, D51, D28) were selected out from 20 synthetic peptides and were used to compare with 2 natural antimicrobial peptides (Decoralin, Pseudin). Among these 5 peptides, two synthetic peptides, D4E1 and D51, showed stronger resistance than the natural peptides, which could inhibit the growth of E. coli and V. dahliae and even kill 100% of conidia at very low peptide concentration, such as 20 μg/mL. The reason for this huge difference might be hydrophobicity of antimicrobial peptides which had been recognized as one of the major parameters influencing the antimicrobial activity of peptides. Two methods, Protein Identification and Analysis Tools on the ExPASy server and Reverse Phase High Performance Liquid Chromatography (RPHPLC), were used to determine their mean hydrophobicity of these peptides. The result revealed that the RPHPLC retention time could be better to understand the relationship between the peptide hydrophobicity and their antimicrobial activities. This study suggested that the synthetic peptides may be stronger in antimicrobial activity than the natural peptides if a good design were taken, and that the amino acid sequence of synthetic peptides with ideal activity, such as D4E1 and D51 in this research, can be deduced into the nucleotide sequence which could be an effective resistant gene against the cotton wilt disease in the transgenic cotton developed by the genetic engineering.

Rhizoctonia solani is an important plant pathogenic fungus with a wide host range and worldwide distribution, and the sclerotia are the main source of infection for the diseases caused by this pathogen. The mechanism of formation and development of sclerotia of Rhizoctonia solan had been investigated by some researches, but they were mainly focused on the relationship between the sclerotium formation and the nutrition or environmental factors. There is still lack of the knowledge on the molecular basis of sclerotium formation of R. solani, and little is known about the sclerotium formationrelated genes.
Subtractive cDNA library of differentially expressed genes during the sclerotium formation of R. solani AG1 IA (GD118 strain) was constructed previously by using suppression subtractive hybridization (SSH) technique in our laboratory. The hyphal and sclerotium mRNA was used as the driver and tester, respectively. In the screening, some specific sclerotium formationrelated gene fragments were identified and sequenced. According to the principle of hybrid SSH, the obtained gene fragments should be hyphal or sclerotium specific, but there were five gene fragments, we named them as A, B, C, E, F, respectively, detected both in hyphae and sclerotia. Bioinformatic analysis showed that these five gene fragments were correspondent with the genes putatively coding twocomponent response regulator, macrophage activating glycoprotein, extracellular elastinolytic metalloproteinase, Cyclophilin, and ERderived vesicles protein ERV29. In this study, realtime quantitative PCR (QRTPCR) was applied to further detect the gene expressions of A, B, C, E, F in different growing stages of R. solani by using the total RNAs as the templates and the 18S rRNA as the reference gene.
The five gene expressions were determined by the QRTPCR and calculated by the relative quantitative method (2-ΔΔCT). The results showed that: all of the five gene expressions decreased gradually from the initiation of sclerotium formation, but increased quickly at near maturation of sclerotia, then remained a constant level after maturation of sclerotia. Moreover, it was shown that these five gene expressions altered significantly among different growing stages of R. solani.
According to the previous reports, the decrease of the expression of these five genes could repress the normal cell metabolism and result in the cell death, suggesting that the death of a large numbers of sclerotium outer cells during the sclerotium formation of R. solani may be associated with the expression levels of these five genes induced by external stresses. Obviously, complex metabolism and signal transduction pathways are involved in the cell death and the sclerotium formation, the detailed functions of these five genes in the signal transduction pathways leading to the sclerotium formation are still unclear and need to be studied deeply in the future.

The banana burrowing nematode, Radopholus similis, is a migratory endoparasite plant nematode and severely harms many tropical and subtropical crops. It is the most important invasive species to banana worldwide, and is listed as a quarantine pest in many countries. Nematicide have been used as the main approach to control R. similis. However, due to the high toxicity, nematicide has led to many environmental problems. Now, gene targeting has become a new sustainable strategy to control plant nematode. Cathepsin B is a lysosomal cysteine protease, and it occurs in a wide range of parasitic and freeliving nematodes. It has been demonstrated that cathepsin B plays a very important role in egg hatching, development, reproduction, invading host, inducing host pathogenesis and immune evasion in parasites. To our knowledge, there are few studies on plant parasitic nematode cathepsin. Until now only one cathepsin B gene from Bursaphelenchus xylophilus (GenBank: GU130153) has been cloned, but the detail gene function is still unclear.
The R. similis cathepsin B gene was cloned and analyzed, to provide a scientific basis for the further research on the function of plantparasitic nematodes cathepsin B, and also for developing new control strategies.
A cDNA library of R. similis was constructed by switching mechanism at 5′ end of the RNA transcript（SMART）technique. The fulllength cDNA sequence of the cathepsin B gene was obtained by the method of splicing leader (SL), and then sequenced. The homolog sequences of cathepsin B were analyzed to generate a phylogenetic tree. The threedimensional structure and the function of the cathepsin B protein were also analyzed and forecasted by bioinformatics technology.
A mixed stages of R. similis complementary cDNA library was constructed by SMART. Altogether 76 expressed sequence tags (ESTs) were analyzed by Blast in NCBI. Of the 76 ESTs, one 600 bp EST sequence showed high homology to the cathepsin B gene of Caenorhabditis elegans. Based on the 600 bp EST sequence, a 1 257 bp cDNA fulllength sequence of the cathepsin B gene from R. similis was cloned by SL, and named as Rscb1 (GenBank accession No:GU360972). A phylogenetic tree was constructed based on the cathepsin B gene sequences of various organisms. The complete Rscb1 ORF is 1 071 bp, and encodes a polypeptide with 356 amino acids (the protein molecular weight is 41.4 ku). The multiple sequence alignment between Rscb1 and the cathepsin B gene of other parasites showed that Rscb1 had the closest genetic relationship with the cathepsin B gene of C. elegans. The function analysis showed that the protein coded by Rscb1 was mainly for cell external secretion protein. The protein was subcellular located in the microbody (peroxisome), the endoplasmic reticulum membrane and the endoplasmic reticulum antrum. A 25 amino acids’ transmembrane section was found at the C terminus of the protein. The protein surface charge was polarity distribution. Threedimensional structure of the protein was drawn by SWISSMODEL. The structure was consistent with the biological function of cathepsin B gene.
Rscb1 was the first record about cathepsin B gene from R. similis. Based on the analysis and forecast, it may have the important biological functions.

Promoter is a key element on gene expression regulation, and it is an emphasis of plant transgenic research. Now, detailed analysis about flowerspecific promoters such as chalcone synthase gene promoter from petunia and lily has been made. Enhancer is another kind of regulatory element usually placed at upstream of promoter sequence. In order to precisely regulate gene expression in plant genetic engineering, scientists put forward a method of designing artificial promoter to avoid homologydependent gene silencing caused by repeatedly using a same promoter sequence. In addition, in order to decrease the size of foreign gene and conform to the trend of multiple genes transformation, the method of using bidirectional promoter was proposed by scientists. According to the previous studies, the present study use core sequence of petunia flowerspecific promoter pPCHS and lily flowerspecific promoter pLCHS, CaMV 35S enhance sequence, OCS enhance sequence to design and construct two enhanced plant flowerspecific bidirectional promoters. We wish to provide some promoters with practical value when we try to use multiple genes transformation method to precisely regulate ornamental traits of some important flower species such as petunia and lily.
In this research, according to the procedure of overlap extension PCR method and sequences of petunia flowerspecific promoter pPCHS, lily flowerspecific promoter pLCHS, CaMV 35S enhancer, OCS enhancer, 10 primers were designed and synthesized firstly. In the first round of PCR process, plasmids which contain abovementioned four sequences were templates; six fragments with overlapping areas were amplified using overlapping primers. These six fragments were named as pPCHS12, pPCHS13, 35S45, OCS67, pLCHS810, pLCHS910. Moreover, Prime StarTM HS DNA Polymerase was used in this PCR process and these six products were all bluntended. In the second round of PCR process, the mixture of products pPCHS12, 35S45, pLCHS810 was a group of template, the mixture of products pPCHS13, OCS67, pLCHS910 was another group, the upstream primer of pPCHS sequence and downstream primer of pLCHS sequence formed a pair of primers. Two products fused with various 3 fragments were produced after overlap extension in this PCR process. Ordinary DNA amplification enzyme was used in the second PCR process; products were cloned through TA clone method and then transferred into E. coli TOP10 for sequencing and preservation.
After final sequencing, two fragments pPCHS35S enhancerpLCHS and pPCHSOCS enhancerpLCHS obtained via overlap extension PCR method were of the same length as our designed two bidirectional promoters, mutation or mismatch did not happen in their sequences, especially some important cisacting elements. So we successfully acquired two enhanced plant flowerspecific bidirectional promoters.
In our opinion, selection of promoter with practical value is a basic work in transgenic research, how to design and construct artificial promoters maybe a considerable area and the study of artificial bidirectional promoters are a new area in the research of promoter. Two enhanced plant flowerspecific bidirectional promoters were rapidly and simply constructed through overlap extension PCR method in this work, we hope they become available molecular tools in ornamental plant genetic engineering.

The BIO organs (BIO) gene is located on the short arm of Chromosome Ⅳ in Lotus japonicus. The bio mutant is obtained from a large scale EMS mutagenesis screen. Gene sequencing have proved that a stop coden appeared earlier in the transcripts of BIO by a retrotransposon insertion, which led to a truncated protein. Morphological analysis showed that the bio mutant displayed enlarged plant organs and a better symmetry in flower. It has been speculated that LjBIO regulate organ morphology and plant size in Lotus japonicus. However, the function and regulation mechanism of LjBIO still remains unclear. Petunia hybrida is a good material for genetic engineering and molecular biology research, due to its short lifecycle, simple growing conditions and mature transgenic system mediated by agrobacterium infiltration. Calli tissues are induced from P. hybrida QL01 explants as transgenic materials in order to gain further information about the function and possible mechanism of LjBIO. The tissue culture and regeneration system of P. hybrid was refined. Different explants from P. hybrida QL01 were chosen and several concentration gradients of 6BA and NAA were tested for selecting the best tissue culture and regeneration system. Agrobacterium mediated gene transformation was used to induce BIO and the mutant gene bio into the calli of QL01. The 35SBIOGFP and 35SbioGFP vectors were transferred into agrobacterium GV3101 by freezing and defreezing immediately using nitrogen and water bath. The target agrobacteria clones were verified by PCR and were cultured overnight into large volume. The agrobacterium were resuspended in MS liquid medium, used to infiltrate the precultured explants for 8 minutes and cocultured for another 3 days in dark. Transgenic plants were obtained and confirmed with hygromycin screening and RTPCR detection. The phenotypes of transgenic plants were recorded and analyzed to
obtain more information about the gene function. Results showed that MS medium with 01 mg/L 6BA was suitable for the growth of P. hybrid and the proliferation of calli from the excised stem. MS medium with 10 mg/L 6BA and 01 mg/L NAA was best for the bud regeneration. 03 mg/L hygromycin was used for resistance screening and 20 different resistant plants were obtained for both BIO and its mutant gene bio respectively. PCR detection of gene expression showed that 15 35SBIO and 17 35Sbio transgenic plants had been successfully obtained. Morphological analysis displayed that both 35SBIO and 35Sbio transgenic plants had abnormal leaves with irregular margins, some of them even showed a tendency that one leaf would be divided into two. In 35SBIO transgenic plants, certain blades had smaller size and became thinner than the wildtype and a few of them only had main veins left. Detailed data showed that leaf surface area and lengthwidth ratio altered obviously. The ectopic and overexpression of LjBIO and Ljbio in P. hybrida revealed that this gene affected not only the size of plant and the symmetry of floral organs, but also influenced the development and morphology of leaf. The study illustrated the essential role of LjBIO gene in maintaining leaf morphology, and displayed that the 3′ end of LjBIO had its unique function worthy of further research according to the different leaf phenotypes between 35SBIO and 35Sbio transgenic plants. This work also provided experimental basis for the further study of regulatory mechanism of LjBIO gene.

There are hundreds of sources of heavy metal pollution, including the industries of coal, natural gas, paper, and mining. Toxic heavy metals, such as mercury, cadmium and lead, in air, soil, and water are global problems that are a growing threat to humanity. Rice is an important food crop in world, the rice polluted with heavy metal is seriously harmful to people’s health. There are many methods to detect the heavy metal, such as inductively coupled plasmamass spectrometry (ICPMS), inductively coupled plasmaatomic emission spectrometer (ICPAES), inductively coupled plasma optical emission spectrometry (ICPOES), atomic absorption spectrometry (AAS), X ray fluorescence spectrometry (XRF), atomic fluorescence spectrometry (AFS) and so on. Although there are many advantages in the above technologies respectively, they are timeconsuming, highcost and sometimes require considerable analytic skill. Nowadays, as near infrared spectroscopy (NIR) responds to molecular energy transitions associated with hydrogen bonds of organic, while inorganic salts are not expected to directly influence NIR spectra. To our interest, several studies have described useful NIR calibrations for minerals analysis. NIR spectra with supposed NIRtransparent minerals may be due to the association of cations with organic or hydrated inorganic molecules. Thus, in order to develop the fast detective technology on heavy metal polluted rice leaves, NIR was combined with pattern recognition to discriminate the mercury, cadmium and lead in polluted rice leaves. The rice was grown in paddy field polluted by mercury, cadmium and lead, the concentration of which was 1.5, 1 and 500 mg/kg respectively. After 50 days growth, the absorbance of near infrared spectroscopy of back of flag leaf was detected with Nicolet Nexus 870 (Thermo Corporation USA) and the data was collected with the software of Omnic 7.0. The acquired spectra of leaves with different heavy metal treatments were firstly pretreated with wavelet transform and then input in pattern recognition models of back propagation neural network (BPNN) and radical basis function neural network (RBFNN). It was shown that the rice could grow, blossom and bear fruit in mercury, cadmium and lead polluted paddy field, the concentration of which was 1.5, 1 and 500 mg/kg respectively. The spectra of rice leaves were firstly pretreated with wavelet db2 function at 05 level, and then calculated with back propagation neural network (BPNN) and radical basis function neural network (RBFNN) model. It was shown that the pretreatment of db2 function at 3 level combined with RBFNN model was best. And the correct classification rates of rice in mercury, cadmium and lead polluted soil and control soil were 95.5%, 81.8%, 91.3% and 100.0% respectively. Our results indicated that it should be feasible to develop useful calibration models for the prediction of heavy metal in rice leaves. The performance of RBFNN model was best in the prediction of heavy metal (mercury, cadmium and lead) polluted rice leaves. It has also provided a basis of NIR on the recognition of heavy metal polluted rice, and then ensure the safety of plant environment.

The dried root and rhizome of Salvia miltiorrhiza Bunge (Lamiaceae, Salvia), one of the popular traditional Chinese medicine (TCM), is officially listed in Chinese pharmacopoeia under the name of Danshen. S. miltiorrhiza have been widely used for treatment of coronary heart disease, cerebrovascular disease, neurasthenic insomnia, bone loss, liver fibrosis, hepatocirrhosis and chronic renal failure. Waterlogging is abiotic stress that influences species composition and productivity in numerous plant communities worldwide. For most crops, excess water is a major constraint to productivity in many regions and situations, and the inability of crops to withstand low oxygen conditions in the root zone will lead to yield losses. Zhongjiang County was the genuine producing areas with a long history
for the plant of Danshen. But now, the effect mechanism of water stress on S. miltiorrhiza was little known. The objective of this study was to elucidate the physiological responses of different S. miltiorrhiza under water stress. The finite element method can be used as academic base for flooding resistance mechanisms, and provide evidence for breeding S. miltiorrhiza varieties and
improving the cultivation technology of resistance to waterlogging. The experiment was conducted in 2010—2011 at the experimental station of Sichuan Agricultural University, Ya′an, Sichuan Province, China. Bigleaf dwarf S. miltiorrhiza, bigleaf tissue cultured S. miltiorrhiza, tetraploid lobular S. miltiorrhiza, tall bigleaf S. miltiorrhiza, Zhongjiang wild S. miltiorrhiza, lobular tissue cultured S. miltiorrhiza were obtained from Zhongjiang County, Sichuan Province. All materials were grown in pots containing a 2:1 mixture of garden soil and vermiculite without any added fertilizer, and were maintained in a rain shelter. The waterlogging treatment was mimicked by treating pot plants with flooding. Investigations were carried out on the changes of malondialdehyde (MDA) content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities and proline (Pro) content of six S. miltiorrhiza varieties. The result indicated that waterlogging stress of 5 days was the optimum condition for the simulation of waterlogging stress. Each variety had different physiological and biochemical response to waterlogging stress. Under the flooding stress, SOD and CAT activity of tissue cultured bigleaf S. miltiorrhiza was the highest, and that of tissue cultured lobular S. miltiorrhiza was the lowest; POD activity of dwarf bigleaf S. miltiorrhiza was the highest, and that of tissue cultured lobular S. miltiorrhiza was the lowest; Tetraploid lobular S. miltiorrhiza contained the most contents of Pro and MDA, while Zhongjiang wild S. miltiorrhiza contained the least content of Pro; Tissue cultured bigleaf S. miltiorrhiza, tall bigleaf S. miltiorrhiza and Dwarf bigleaf S. miltiorrhiza contained the same content of MDA which was lower than the other three varieties. Correlation analysis showed that there was no prominent correlation among all these indexes. Actually, they have independent functions. Therefore, each one can be regarded as physiological index of water tolerance for S. miltiorrhiza. In conclusion, the research results suggested that: i) Waterlogging stress of 5 days was the optimum condition for the simulation of waterlogging stress. ii) Each variety of S. miltiorrhiza had different physiological and biochemical response to waterlogging stress. iii) Each index can be regarded as physiological trait of water tolerance for S. miltiorrhiza seedlings.

Melanose (Diaporthe citri), black spot (Guignardia citricarpa) and greasy spot (Mycospharella citri) of citrus have been becoming more and more serious and widespread, causing significant losses to the Chinese citrus industry by reducing yield and fruit quality in recent years. Although the improvement of cultural practices has the positive effect, application of fungicides is still the primary and effective means to control these diseases. Difenoconazole（belong to 14αdemethlylation inhibitors，DMIs) is a fungicide recently registered for use on citrus in China. ZJ0712 (belong to strobilurin, QoI), developed independently by our country, has a high potential in controlling citrus fungal diseases. The objective of this study was to establish the baseline sensitivity of these citrus fungal pathogens to these fungicides prior to their widespread use.
Fortyeight singlespore strains of D. citri, 46 strains of G. citricarpa and 50 strains of M. citri were collected from main citrusproducing regions in China. The effective dose to reduce mycelial growth or spore germination by 50% (EC50 values) of each strain was determined by using eight different concentrations of fungicides. The results demonstrated that the baseline sensitivities for mycelial growth of D. citri, G. citricarpa and M. citri to ZJ0712 were 0003, 0011 and 0035 μg/mL, respectively; to difenoconazole were 0149, 0008 and 0970 μg/mL, respectively. The baseline sensitivities for conidial germination of D. citri to ZJ0712 was 0001 μg/mL, but > 25 μg/mL to difenoconazole.
These results above indicated that the populations of D. citri, G. citricarpa and M. citri were sensitive to ZJ0712, and the populations of G. citricarpa and M. citri were sensitive to difenoconazole, implying widely potential usage of these fungicides in controlling the diseases above. Determination of the baseline sensitivities of D. citri, G. citricarpa and M. citri should also facilitate the detection and verification of pathogen resistance development to ZJ0712 and difenoconazole.

Bud dormancy is an adaptive developmental process for perennial deciduous fruit trees to survive under the adverse environmental conditions, which is released when both the chilling requirement and growth temperature are achieved. Prolonged dormancy is considered to be the major obstacle to economic production of temperate fruits in warm winter regions. In Southern China, due to warm winter temperature, dormancy release becomes a major factor for production of Pyrus pyrifolia cv. Cuiguan. The irregular blossoming and delayed flowering behavior present in this crop may cause negative influence on pear industry of this region. In view of limiting factor in particular regions, the need for artificial means to compensate for lack of natural chilling for maintaining economic production of pear crop. Chemicals likewise hydrogen cyanamide (HC) and thiourea is widely used to overcome the bud release problem of insufficient chilling for deciduous fruits. P. pyrifolia is a good early maturing cultivar and commercially grown in the region of Southern China. Now, Hydrogen cyanamide (HC) was used as a dormancy breaking agent for P. pyrifolia. Different concentration of hydrogen cyanamide (HC) was used to release floral buds from dormancy and duration of dormancy releasing periods of buds, to analyze the variation in endogenous hormones and carbohydrates.
Survey was made during the phenological periods including floral bud breaking, flowering and fruit maturing and investigation were made by enzymelinked immunosorbent assay（ELISA） for the occurrence of changes in endogenous hormone contents including gibberellin (GA3), abscisic acid (ABA) and zeatin riboside (ZR) and the data was recorded for carbohydrate conversion between starch and soluble sugar in floral bud. Data regarding phenological phase were analysed statistically. Results presented indicated that
higher concentration of hydrogen cyanamide treatment (2%) was significantly proved better for early bud break and also in florescence period (both the initial flower stage and fullblossom stage).
However, all the level of HC treatment did not affect significantly on frutescence period, the fruit firmness and total soluble solid content. As far as endogenous hormone content changed in floral bud after hydrogen cyanamide treatment, gibberellins contents showed the tendency like ‘ascentdecentascent’, in early days of application, while after twenty days, at 2% concentration, HC caused a significant increase in endogenous GA3, those were higher level as compared to non treated sample (control). Obtained results further depicted that the maximum contents of abscisic acid (ABA) was yielded as a result of hydrogen cyanamide
treatment as compared to other endogenous hormones. The rise in endogenous hormones (ABA and GA3) as a result of the higher HC dose may be due to direct stimulation of ABA and GA3 synthesis by HC.
Keeping the presented results in view, it might be presumed that abscisic acid would play an important role in dormancy release after hydrogen cyanamide treatment. Moreover the conversion from starch to soluble sugar in floral bud indicates that the activity of meristem is increased with the dormancy release.
Therefore, on the basis of obtained results it is concluded that hydrogen cyanamide treatment could overcome the problem of prolonged dormancy and shorten the bud dormancy release period without affecting the fruit quality i.e. firmness, sugar content and total soluble solid.

In recent years, with the increase of peach cultivation area and yield, the techniques for the peach postharvest disease control need to be improved. Since the 1980s, due to a variety of advantages, such as safety, effectiveness and without causing antibiotics resistance, biological control has become more and more important for fruits and vegetables postharvest preservation. Although many kinds of biological control agents have been developed, antagonism yeasts still have wide application prospects because of their convenient use. This study aimed at systematic classification and identification of the yeast strain A822 and studied the antagonism effect on peach soft rot diseases Rhizopus stolonifer. To study the inhibitory effect of strain A822 on R. stolonifer, four different experiments were designed, including the antifungal test on plates, the mixed strains culture experiments, the antibacterial test using fermentation broth and inhibitory studies on peach fruit in vivo. Regarding to classification and identification of strain A822, we used general classification methods such as observation of the yeasts morphology, and characterization of physiology and biochemistry, supplemented with molecular biology methods to analyze 26S rDNA sequence. First of all, using four different antifungal experiments stepbystep demonstrated the obvious inhibitory effect of yeast A822 on R. stolonifer. The inhibitory test of yeast A822 on plates showed the notably antagonistic action on R. stolonifer; the mixed strains culture experiments indicated the inhibitory effect of yeast A822 on R. stolonifer growth and there is obviously positive correlation with concentration of yeast A822; the suppressive test of yeast A822 fermentation broth demonstrated that there was no antifungal substance secreted outside yeast A822 cell, and further investigation results showed that the inhibitory action was achieved through nutritional competition and spatial competition between strain A822 and R. stolonifer, rather than yeast A822 producing any antifungal substances to inhibit the growth of R. stolonifer; In vivo studies showed that the 1×108 cfu/mL concentration of yeast A822 has a significant inhibitory effect on peach fruits which were inoculated with the 1×105 spores/mL concentration of R. stolonifer. Secondly, through general classification methods including observation of the yeasts morphology, and characterization of physiology and biochemistry, it was found that the characteristics of the strain A822 was closest to Pichia sp. Furthermore, molecular methods was used to analyze the 26S rDNA sequence of strain A822, and by sequence comparison in GenBank, the antagonistic yeast A822 was ultimately determined as Pichia anomala. As safe and effective antagonistic fungi, yeasts have been highly concerned, researchers have been discovered many yeast species with biocontrol effect. However, at present there is no report that P. anomala had antagonistic effect on R. stolonifer. This study firstly identified that P. anomala A822 had an inhibitory effect on R. stolonifer, and its inhibitory mechanism was clarified. Based on the above results, we concluded that P. anomala A822 significantly inhibited R. stolonifer, therefore it has an important application potential in biological control and post harvest preservation of fruit and vegetable.

Assessment of tea quality is mainly achieved by sensory evaluation currently, which is easily affected by people’s subjective factors and environmental factors. So an objective assessment method for evaluation of tea quality is necessary. Aroma of tea is one of the most important factors determining its quality. In recent years, there were many reports on the analysis of tea aroma related to the quality of tea using gas chromatographmass spectrometer (GCMS) technology, but most of the GCMS techniques were limited in the identification of aroma components. Another kind of study of the tea quality was using chemometrics analysis on the data of nearinfrared spectra, electronic nose, electronic tongue and so on. In fact, the data of nearinfrared spectra, electronic nose, electronic tongue was the total indication of the tea aroma or taste and no relationship between the tea quality and its components were obtained. It is well known that the chemical components of tea is in good relation with its quality, but until now there are few reports on the quality analysis of tea products using chemometrics based on the chemical components information. In this work, GCMS and chemometric analysis was combined to study the possibility to classify different kinds of tea samples and evaluate their qualities. The experiment was carried out as follows. Tea aroma components were collected by headspace solidphase microextraction (extraction temperature is 50 ℃, extraction time is 50 min, tea amount is 3.0 g and water volume is 30 mL) and then subjected to GCMS analysis. Aroma components were identified through mass spectra library and published references. The GCMS data of the aroma components was analyzed by principal component analysis (PCA) and partial least squares regression (PLSR) analysis. The quality of tea were judged predictively combined with sensory evaluation. Results showed that Dafolongjing, Xihulongjing, jasmine tea, Dianhong and Qihong can be discriminated by PCA, the recognition accuracy for 10fold crossvalidation and back substitution were both 100%; The grade of Dafolongjing, jasmine tea, Dianhong and Qihong were predicted well by PLSR on the GCMS data, the correlation of predicted value and actual value were 0.98, 0.94, 0.99, 0.98 respectively, indicating that there is a nice prediction for grade (price) of Dafolongjing, jasmine tea, Dianhong and Qihong. It was concluded from the study that good classification of different kinds of tea, and predication of tea samples according to the quality could be obtained from chemometrics analysis based on GCMS data, indicating that chemometrics analysis based on the chemical components was possible. This method could be furthered in the fingerprint analysis of tea products.

China is a big producing country of fruits and vegetables, but the export price is quite low due to the lack of suitable grade classification technologies.
Domestic academics have been dedicating themselves to ameliorating the detection technology to change this situation. Xray computed tomography (CT), making use of the specific penetrativity, can acquire an accurate faulted image which contains many internal quality information of fruit.
In order to detect the character of apples quickly without damaging the sample simultaneously, a model was established based on the faulted image and some effective information related to the internal quality.
Although the average CT number of pulp area in an apple profile has a good linear relationship with the quality, it is of little practical value when popularized. We intend to make CT nondestructive detection method much more useful in the prediction of the apple quality. Firstly, the window/level number of CT image should be unified at an appropriate level, before building the model between CT numbers and gray level values. Secondly, the atactic pulp area should be separated from the faulted image by means of a segmentation algorithm named Otsu, which is an adaptive threshold method. Thirdly, the weighted mean of pixel numbers in this area should be calculated and converted into CT average numbers according to the relationship built before. Finally, the model of the relationship between the CT number and the internal quality in the area was developed. The model can be used to predict and analyze the apple quality. Generally, we had an arbitrary scale with air defined as having a CT number of -1000 HU and water of 0 HU. In our experiment, we detected the CT numbers of apple pulp ranging from -380 HU to 20 HU, which was will corresponded to the internal structure of apple. For the significant influence emerged by the window/level number in the process of converting the DICOM (digital imaging and communications in medicine) image into gray level image in BMP format, the window/level number must be unified. In comparison, we can get the clearest image at 430/-210. Then a regression model was set up between the CT numbers and the gray level values, which showed a good linear relationship with the R2 reaching 0.970 8. In consideration of the results obtained by some image segmentation algorithms, Otsu (maximum between clusters variance method) was put into use. It had different segmentation thresholds by computation, ranging from 71 to 91. At the same time, the weighted mean of pixel number can also be acquired from each gray level image by Otsu, and then the CT average numbers were converted from the pixel numbers. Finally the models between CT average numbers and the apple internal quality parameters were established, showing good linear relationships between CT number and the main under as sugar, titratable acidity and moisture, with the R2 values of 0.8464, 0.8233, 0.9075, respectively, and the prediction error can be controlled within 50%, 74%, 38%. It can be concluded that the internal quality of apple can be predicted by the CT faulted image quickly and nondestructively. We also found that the window/level number in the picture format of DICOM would significantly affect the gray level in BMP format, but in a fixed number, the two had a good linear relationship. The pulp area can be well separated from the whole image by Otsu, as well as figuring out the CT average numbers. At last we build three linear regression models between the number and the sugar, the titratable acidity, and the moisture separately, with good related coefficients and low forecast errors.

Diarrhea in preweaning and postweaning piglets is still a frequently occurring disease on
scaled farms, and result in great economic losses. Enterotoxigenic Escherichia coli (ETEC) is a major cause, and
the virulence factors are the key to its pathogenicity. The traditional and commonly detected pili of ETEC are F4（K88），F5（K99），F6（987P），F18 and F41, and the enterotoxins include heatstable STa and STb，heatlabile enterotoxin LT and Stx2e. However, new reports
have shown that ETEC strains lacking of recognized fimbriae are becoming increasingly common, which may be linked to the use of vaccines incorporating fimbriated strains, providing selection pressure for the acquisition and carriage of novel, unrecognized virulence genes. Recently, EAST1 (enteroaggregative Escherichia coli heatstable enterotoxin 1）， PAA (porcine attaching and effacingassociated factor), AIDAI (adhesin involved in diffuse adherence）and intimin encoded by eae （Escherichia coli attaching and effacing） have been reported. Nevertheless, few related data have been available in China; furthermore, the prevention strategies have been devised largely based on the virulence factors. In order to gain more insight into the pathogenesis of colibacillosis in piglets and control the disease, it is of significant importance to track the changes of E. coli virulence factors and antimicrobial resistance, and elucidate the possible relationship between them.
Samples were collected by rectum swabs from diarrheal piglets on intensive pig farms of Zhejiang Province. A total of 124 pathogenic isolates were obtained after bacteria isolation, purification, and identification based on the combination of morphology and PCR techniques. The virulence factors were verified by PCR with specific primer pairs. Susceptibility testing was carried out by KB method, and analyzed by Whonet software. The correction between antibacterial resistance and virulence factors was evaluated by Logistic regression analysis. The PCR results showed that fimbriae positive (F4+ and F41+) amounted to 7.26% (9/124). EAST1, PAA and AIDAI were detected for the first time in the region. EAST1 turned out to be as high as 19.68% (24/124) of the isolates, whereas only 4.84% (6/124) and 2.42% (3/124) of the isolates harbored PAA and AIDAI, respectively. Isolates were highly resistant to oxacillin (100%), cotrimoxazole (97.6%), rifampicin (97.6%), doxycycline (96%), carbenicillin (93.5%), ampicillin (93.5%) and amoxicillin (93.5%). In addition, streptomycin showed serious crossresistance with ampicillin (75.45%), enrofloxacin (65.45%), gentamicin (78.18%), doxycycline (96%) and florfenicol (50.91%). Besides, all isolates were multidrug resistant among them, the majority
were resistant to 1416 antibacterial agents (43.31%).Moreover, virulence
factor eae was found to be corrected with amoxicillin/clavulanic acid (P=0.046) and doxycycline (P=0.020) resistance, respectively. Similarly, there was a significant correction between EAST1 and polymyxin B (P=0.004), EAST1 and chloramphenicol (P=0.013), respectively. This investigation demonstrated that prevalent virulence factors had largely changed compared with previous studies, and resistance
was still on the increase, furthermore, there existed a correlation between them. Further research is required to better understand the complicated virulence factors, bacterial resistance and its subtle correction.

Traditional Chinese medicine is rich in resources and has the characteristics of low prices and lowtoxic side effects, which is widely used in the treatment of animal diseases, including viral diseases. Duck plague virus (DPV) is an acute, contagious herpesvirus infection of duck, geese, and swans of all ages and species. This disease has been responsible for significant economic losses in domestic and wild waterfowl as results of mortality, and decreased egg production. There is no effective drug on the therapy of this virus disease.
We attempted to screen out a few of effective traditional Chinese medicines on DPV from eighteen kinds of traditional Chinese medicines. The methods were as follows. At first, the cytotoxic effect of the water extracts and alcohol extracts of the traditional Chinese medicines on DEFs monolayer were determined by the method of cytopathic effect (CPE). All the concentrations of extracts used in antiviral activity assays were below the maximal noncytotoxic concentration (MNCC). In the antiviral activity assay, the method of CPE was used in preliminary screening for the effective extracts. The virus inhibitory ratios of the effective extracts against DPV were tested by the method of ［3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide, MTT］
colorimetric analysis. The results showed that the virus inhibitory ratios against DPV were 7650% and 4891% with the concentrations 00625 mg/mL and
00078 mg/mL of Rhizoma polygoni cuspidati and Radix rubiae.
Additionally, the 50% inhibitory concentration of Rhizoma polygoni cuspidati and Radix rubiae were 00227 mg/mL and greater than 00078 mg/mL respectively. The result above indicated that the alcohol extracts of Rhizoma polygoni cuspidati and Radix rubiae showed the antiviral activities at varying degrees in vitro and the Rhizoma polygoni cuspidati, whose antiviral activity is better than Radix rubiae, might be a potential agent in the prevention of DPV infections.

Chromium as a beneficial element was occasionally indicated by more and more investigations reported. Trivalent chromium Cr(Ⅲ) has been accepted as an essential element for 30 years which can affect the growth performance, carcass characteristics, pork quality, reproduction and tissue deposition of domestic animals that were fed with Cr(Ⅲ) supplementation in diet through changes protein, nucleic acid and lipid metabolism. Chromium is found in GTFlike forms in the livers of mammals given inorganic chromium, but this could reflect the manifold effects of insulin rather than further biochemical roles for chromium. Moreover some
other reports indicated Cr(Ⅲ) appeared not to be an essential element, and its potential effects on domestic animals might be considered pharmacological. Limited research is available for addressing the effect of Cr on meat quality of broiler elucidated by determining the fiber muscle density, total antioxidant capacity and amino acid content. Thus, the purpose of present experiment was to evaluate the effects of three different sources of chromium (yeast chromium, chromium picolinate and methionine chromium) on meat quality and amino acid content of Arbor Acres (AA) broilers. Seven hundred and ninetytwo onedayold Arbor Acres broilers were randomly allocated to six dietary treatments. Each treatment had four replicates (cages) with thirty three broilers per cage, respectively. The dietary treatments were: 1) cornsoybean meal basal (B: according to NRC, 1994), 2) B + 02 mg/kg of Cr (as yeast chromium), 3) B + 02 mg/kg of Cr (as chromium picolinate), 4) B + 01 mg/kg (as methionine chromium;Ⅰ), 5) B + 02 mg/kg (as methionine chromium;Ⅱ), 6) B + 06 mg/kg of Cr (as methionine chromium; Ⅲ). The fiber density, fiber areas and its antioxidant index of leg muscle, as well as amino acids content of muscle were determined. The results showed that the fiber density of breast muscle and fiber areas of leg muscle were reduced (P<005) in broilers fed with yeast chromium diets, fiber density of breast muscle was reduced (P<005) in broilers fed with methionine chromium（Ⅱ） diets, fiber areas of breast muscle and leg muscle were reduced (P<005) in broilers fed with methionine chromium (Ⅰ) diets compared with broilers fed with the control diets. Protein content of breast muscle was reduced (P<005) in broilers fed with chromium picolinate diets, and fat content of breast muscle was reduced (P<005) in broilers fed with methionine chromium (Ⅱ) diets. Antioxidant index of breast muscle and leg muscle were not affected (P>005) by treatments, with the exception that, total antioxidant capacity (TAOC) of leg muscle from broilers fed with methionine chromium (Ⅱ), total antioxidant capacity (TAOC) of breast muscle and catalase (CAT) of leg muscle from broilers fed with methionine chromium (Ⅲ), all of these had an increased (P<005) than broilers fed with the control diets. Main amino acids of muscle were not affected (P>005) among treatments, with the exception that the alanine content of breast muscle in broilers fed with chromium picolinate reduced (P<005) compared with that of broilers fed with the control diets. These suggested that dietary supplementation of yeast chromium or methionine chromium in broilers had a significant effect on muscular tissue structure and oxidation resistance of muscle; however, the main amino acids of muscle were not affected by treatments.