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25 March 2015, Volume 27 Issue 3 Previous Issue    Next Issue

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Study on seed germination and stress\|responsive gene expression of tobacco seedlings from different areas and altitudes SONG Bi\|qing1，2，*，WANG Sha\|sha3，*，ZHENG Yun\|ye1，2，MA Wen\|guang1，2，** 2015, 27(3):  321.  Abstract ( 417 )   PDF (993KB) ( 1251 )   Seed germination rate， stress\|related gene expression and seedling growth rate in tobacco seeds of MS K326 were determined， which produced in different areas with different altitudes. The results indicated that seed germination percent of tobacco from low altitude was the highest at 4th day. After 5th day， there was no significant difference in germination percent of seeds produced from different altitudes. Differences in expression levels of genes involved in multiple stress\|responsive pathways， including antioxidant system， osmotic adjustment and transcription factors were observed at 7th day， and then the difference decreased at 14th day， and there was no significant difference at 21st day. In six production areas， the seedling emergency time were a little different among the tobacco seeds from different altitudes， but the seedling time were the same. Accordingly， the germination percent and stress\|related gene expression of MS K326 seeds， which produced in different altitudes， showed no significant difference after 14 days germination. Related Articles | Metrics

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Detecting the rice blast resistance genes and brown planthopper resistance genes by gene functional marker ZHAO Xiao\|yan1，2， YE Sheng\|hai2， LI Xiao\|hua2， YU Peng1，2， CHEN Lei2， ZHAI Rong\|rong2， JIN Qing\|sheng2， ZHANG Xiao\|ming2，* 2015, 27(3):  327.  Abstract ( 394 )   PDF (532KB) ( 1234 )   Breeding and utilizing resistant rice cultivars is an effective method for controlling rice blast and brown planthopper. The rice blast resistance genes Pi\|b， Pi\|k， Pi\|ta and brown planthopper resistance genes bph2， Bph3 of 2 male sterile lines and their 16 restorer lines were detected by gene functional marker. The results showed that 11 tested materials contained gene Pi\|b， 13 tested materials contained gene Pi\|k， 9 tested materials contained both gene Pi\|b and Pi\|k， and 3 tested materials contained gene bph2. It laid the foundation for the gene pyramiding and breeding the excellent rice cultivars with broad spectrum and durable resistance to rice blast and brown planthopper by molecular identification to related resistance genes of rice cultivars. Related Articles | Metrics

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Preparation and identification of monoclonal antibodies against recombinant porcine interfer\|α ZHOU Xiao\|li1，2， YUAN Xiu\|fang1， DU Xiao\|li1，3， LI Jun\|xing1， XU Li\|hua1， WANG Yi\|cheng1，* 2015, 27(3):  332.  Abstract ( 367 )   PDF (776KB) ( 1202 )   By the fermentation reactor and Pichia pastoris expression system， the expression of recombinant porcine interfer\|α （rPoIFN\|α） was induced with methanol. The rPoIFN\|α was purified by ammonium sulfate precipitation， Q\|Sepharose fast flow chromatography and gel filtration in turn. 6\|week\|old BALB/c mice were immunized for three times with purified rPoIFN\|α， then mouse myeloma cells and the spleen cells of the BALB/c mice were fused. Five hybridoma clones secreting antibody against rPoIFN\|α were obtained by screening with the indirect ELISA and 3-5 times of subcloning. The five McAbs belonged to IgG I isotype， and showed specificity reaction to rPoIFN\|α by Western\|blot. ELISA showed that their antigen binding sites were the same. This paper is beneficial to study the applications of monoclonal antibody（McAb） against rPoIFN\|α in immunology and disease diagnosis. Related Articles | Metrics

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Associations between three SNPs in 3′ UTR of the bovine IL8 gene and milk performance traits of Chinese Holstein cow FANG Yuan\|yang1，2， SONG Xue\|mei2， JIANG Jun\|fang1， JIANG Yong\|qing2，* 2015, 27(3):  338.  Abstract ( 376 )   PDF (646KB) ( 1201 )   In order to clarify interleukin 8 （IL8） gene in the genetic variability of different domestic cattle populations， we detected IL8 gene 3′ untranslated region mutations among Chinese Holstein， Wenling humped cattle and Wenzhou buffalo by application of PCR\|SSCP technique. One haplotype block， containing g. 2831A/G， g. 2904 T/C， and g.3030 G/A was identified in 3′ UTR of IL8 gene by PCR\|SSCP and DNA sequencing in Chinese Holstein and Wenling humped cattle， while Wenzhou buffalo individuals were homozygous for the “mutant allele” in the same loci. The effect of IL8 gene 3′ UTR polymorphisms on Chinese Holstein 305\|day corrected milk yield fat percentage， protein percentage and somatic cell score was assessed by general liner mode. Three mutations in IL8 gene 3′ UTR were significantly associated with Chinese Holstein 305\|day corrected milk yield （P<001） and fat percentage （P<005）. Related Articles | Metrics

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Analysis of relationships between nucleic acid and protein concentration and orphological characters and body weight of Crucian carp TONG Xue\|hong1，2，YAO Li\|hong2 2015, 27(3):  343.  Abstract ( 365 )   PDF (432KB) ( 1207 )   Morphological characters and biochemical indicators， including body thickness （BT）， body height （BH）， body length （BL）， total length （TL）， body weight （BW） and concentrations of RNA， DNA and total protein in the muscle of Crucian carp， were determined. The relationships among above indicators were also analyzed. Data revealed that five indicators of BT， BL， TL， DNA concentration and protein/DNA had significant correlation with BW （P<005）. The direct effect of BT on BW was the highest （0587）， while the direct effect of DNA concentration on BW was negative， which influenced BW mainly through BT. The order of decision coefficients among above indicators with BW was DBT＞DRNA/protein＞DDNA. The codetermination effects on BW was the maximum（0313） for BT and DNA concentration， and the minimum （0007） for DNA concentration and RNA/protein. The relation between weight and morphological characters and biochemical indicators was established by multiple regression analysis. The results showed that power function relationship between DNA concentration and BW， exponential function relationship between protein/DNA and BW， and multiple regression relationship among the other indicators and BW were observed， respectively. Related Articles | Metrics

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Separation， purification and in vitro activity of antioxidant peptides from Whitmania pigra YIN Na1， LIN Xiao\|qing2， YANG Yue\|wei1， XU Hai\|sheng2，* 2015, 27(3):  348.  Abstract ( 315 )   PDF (659KB) ( 1200 )   Separation of antioxidant peptides from enzymatic hydrolysates of Whitmania pigra and their antioxidation activity were studied. Ratio of solid to liquid， enzyme dose， temperature and hydrolysis time were selected as factors to optimize the hydrolysis parameters with four factors and three levels of the orthogonal experiment. Antioxidant peptides were separated and purified from the crude enzymatic hydrolysates by CM Sepharose Fast Flow and Sephadex G\|25 gel chromatography. The antioxidant capability of each component and distribution of molecular weight were determined. Results showed the optimum condition for the enzymatic hydrolysis was as follows: ratio of solid to liquid 1∶4， enzyme dose 7 500 U·g-1， temperature 40℃， time 4 h and primary pH value 85. The scavenging effects of antioxidant capability of each component on hydroxyl radical and ABTS radical were obvious and stronger than that of ascorbic acid. Whereas， their scavenging effects on superoxide anion radical were weaker than that of ascorbic acid. Moreover， the results indicated that molecular weight of these antioxidant peptides was mainly in the range of 13096-33034 u. Related Articles | Metrics

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Cultivation， molecular identification and microscopic observation of Balantidium coli isolated from pig SHI Tuan\|yuan1， FU Yuan1， BAO Guo\|lian1， SUO Xun2， HAO Li\|li3， WANG Yi\|cheng1， LI Jun\|xing1， ZHOU Yong\|xue1 2015, 27(3):  354.  Abstract ( 403 )   PDF (1638KB) ( 1295 )   Balantidiosis is a cosmopolitan parasitic zoonosis. In the study， a Balantidium coli was isolated from the cecum of a severely diarrheal pig in Zhejiang province of China. RPMI1640 medium was used to cultivate the trophozoites of B.coli. Trophozoites grew well in the RPMI1640 medium at 28℃ or 37℃ and the maximum growth density of 818×103 and 231×104cells·mL-1 was gained on the fifth and fourth day post the inoculation， respectively. Cytostome， cytopyge and food vacuole were obviously observed under the light microscopy in the trophozoites. Macronucleus obviously showed dumbbell\|like after DAPI staining. Two different types of trophozoites， large one and small one， existed in B.coli. And two different sequences of 18s rRNA gene were gained for the B.coli after the PCR and DNA sequencing. Divergence between the two sequences was 06%. The two sequences formed a single branch separated from the reference 18s rRNA gene sequences of B.coli in the phylogenetic tree. In addition， a lot of microorganisms were seen at high magnification of microscopy in the B.coli. Species for these microorganisms were unknown. Three novel sequences of 16s rRNA gene was gained after the PCR with B.coli culture as the template. Relationship between the three novel sequences and the endocytobionts was needed to be further confirmed. Related Articles | Metrics

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Construction and evaluation of yeast two hybrid library of Cymbidium goeringii during flower development QIN De\|hui， XIANG Lin， LI Xiao\|bai， WU Chao， SUN Chong\|bo* 2015, 27(3):  360.  Abstract ( 354 )   PDF (1190KB) ( 1230 )   A yeast two hybrid cDNA library of Cymbidium goeringii during flower development was constructed using the CloneMinerTM cDNA Library Construction Kit. Purified plasmid DNA and linear vector （pGADT7\|Rec2\|DEST） were co\|transformed into yeast strain Y187. The results showed that the primary library contains 147×107 independent clones and the yeast two\|hybrid library contains 254×107 independent clones. The sizes of most inserts were 1\|2 kb in length. These results showed that the library was high quality， which is suitable for the screening of flower development related up\| and down\|regulated genes and provide an important foundation for the studies on the molecular mechanisms involved in flower development of Cymbidium goeringii. Related Articles | Metrics

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Effect of towel gourd as rootstock on thermal tolerance of cucumber seedlings HAO Ting*，DING Xiao\|tao*，YU Ji\|zhu**，ZHANG Hong\|mei，JIN Hai\|jun 2015, 27(3):  365.  Abstract ( 601 )   PDF (718KB) ( 1249 )   Under hydroponic culture， effects of high root\|zone temperature， high air temperature and the above temperature interaction （overall high temperature） on relative chlorophyll content （SPAD value）， chlorophyll fluorescence and photosynthesis parameters in leaf， the content of malondiadehyde （MDA）， proline， soluble protein and total sugar of “Wuyexiang” towel gourd rootstock grafted seedlings and self\|rooted cucumber seedlings in leaf and root were studied. Towel gourd rootstock grafted seedlings showed higher SPAD values， excitation energy capture efficiency of photosystem （PSⅡ） reaction center （Fv′/Fm′）， actual photochemical efficiency of PSⅡ （ΦPSⅡ）， leaf net photosynthetic rate （Pn）， transpiration rate （Tr） and photochemical fluorescence quenching coefficient （qP） than self\|rooted seedlings. And the former ones in roots had lower MDA content and higher proline content than the latter ones. The contents of soluble protein and total sugar in leaf and root also changed under the above three treatments with different rootstocks. The results indicated that grafting could relieve the heat stress of cucumber in some extent by changing the content of some substances in roots and leaves under different heat treatments. Related Articles | Metrics

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Screening of salt tolerance germplasms and tagging of the tolerance gene（s） using RAPD and SSR markers in pumpkin WANG Ying\|er1， GAO Xu1，2， WANG Yu\|hong1，*， SONG Hui1， YING Quan\|sheng1， ZHANG Xiang\|qin1， YAN Lei\|yan1， ZHANG Yan\|yu1，2 2015, 27(3):  372.  Abstract ( 446 )   PDF (985KB) ( 1247 )   In this study， salt\|tolerant pumpkin NM083 and salt\|susceptive pumpkin XBZM were screened by salt tolerance test， and the seedling emergence rate and salt injury index were used as the salt tolerance identification index. The F2 segregated population originating from a cross between pumpkin inbreed NM083 （male parent， salt\|tolerant） and XBZM （female parent， salt\|susceptive） was constructed. Among 600 RAPD and 44 SSR primers， a total number of 18 markers （10 RAPD and 8 SSR） showed the polymorphism between two parents， and the ratio of polymorphism RAPD markers and SSR markers in two parents was 043% and 43%， respectively. Among 18 markers， one RAPD primer（P597） was screened out， which could amplify a polymorphic locus （685 bp） between two parents and between salt\|tolerant and salt\|susceptive bulks.The salt\|tolerant test in 160 F2 segregated populations showed that the polymorphic locus （685 bp） appeared in salt\|tolerant F2 segregated population but not in salt\|susceptive F2 segregated population. It could be concluded that this band was the RAPD marker closely related with salt tolerance of pumpkin， which could be used as the effective marker in molecular assisted selection of new varieties breeding of salt\|tolerant pumpkin. Related Articles | Metrics

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Study on optimization of micro\|propagation system of Dendrobium officinale Kimura et Migo LU Zhong\|hua1，2，3,WU Xue\|li2， WANG Hui\|zhong4 2015, 27(3):  380.  Abstract ( 492 )   PDF (720KB) ( 1242 )   In order to optimize the micro\|propagation system of Dendrobium officinale， the aseptic seedlings were used to study the effects of minimal medium， banana amount， activated carbon concentration， NAA concentration， light source， illumination time and temperature on the growth of seedlings through single\|factor experiments. The results showed that the best strengthening medium for seedling growth of Dendrobium officinale was the B5（or improved MS2） with 70 g·L-1 banana， 03 g·L-1 activated carbon， 15 mg·L-1 NAA and 30 g·L-1 sucrose， and the optimum culture condition was at red LED light source， illumination time of 16 h·d-1， and the temperature of （25±1）℃. Related Articles | Metrics

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The sensitivity of Aenasius bambawalei to chlorpyrifos and imidacloprid and its detoxification enzyme activities DU Liang1，HUANG Fang2，WANG Fei\|fei2，LU Yao\|bin1，2，* 2015, 27(3):  387.  Abstract ( 375 )   PDF (921KB) ( 1217 )   In this paper，LC50 of chlorpyrifos and imidacloprid to Aenasius bambawalei were estimated by spray and leaf\|dipping methods，the individual development together with parasitization efficiency and some relative detoxification enzymes of the parasitoids were determined by spray method. The results showed that 1） by spray，LC50 to chlorpyrifos was 2595 μg·L-1，and imidacloprid was 0115 mg·L-1；2） by leaf dipping method，chlorpyrifos was 0112 μg·L-1，and imidacloprid was 0234 mg·L-1；and 3） the lethality of chlorpyrifos was higher than imidacloprid. These two pesticides had significant effects on the parasitization efficiency of the parasitoid，but no effect on the hind tibia length of the adults. Activity of AchE after chlorpyrifos treatment was inhibited by 764%，while activities of CarE and MFO in the imidacloprid treatments were inhibited by 853% and 322%. Related Articles | Metrics

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Isolation and identification of Purpureocillium lilacinum and its pathogenicity against Diaphorina citri DU Dan\|chao， LU Lian\|ming， HU Xiu\|rong， HUANG Zhen\|dong， ZHANG Li\|ping， CHEN Guo\|qing* 2015, 27(3):  393.  Abstract ( 541 )   PDF (1105KB) ( 1324 )   One fungal strain was isolated from Diaphorina citri and named as ZJPL08. Cultural and morphological characteristics of strain ZJPL08 were examined， its rDNA ITS gene sequence was coloned and analyzed， and the pathogenicity of conidial suspensions at different concentrations against D. citri was determined. The results showed as follows: the color of strain ZJPL08 colony on potato dextrose agar （PDA） plate was pale purple to deep purple， and powdery conidia were produced abundantly on the colony; phialides developed at the end of the conidiophore were in whorls of 3～5， and in size of （75-90） μm×（18-30） μm; Conidia was oval or fusiform and in size of （15-28） μm×（13-25） μm. The rDNA ITS sequence of strain ZJPL08 shared 100% similarity with corresponding sequences of some Purpureocillium lilacinum strains deposited in GenBank. Based on the morphology and its rDNA ITS sequence， strain ZJPL08 belonged to P. lilacinum. Under the same concentration of conidial suspension， the mortality of D. citri gradually increased with the culture time prolonged. At the same culture time， with the increase of the conidial suspension concentration， the mortality of D. citri gradually increased. Related Articles | Metrics

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Identification of blueberry mycorrhizal fungi and its effect on blueberry growth ZHAO Ying1， YANG Tao1， SUN Jin\|jie2， YANG Zhen1， WANG Hong1， XIAO Jun1，* 2015, 27(3):  400.  Abstract ( 428 )   PDF (1744KB) ( 1323 )   The taxonomic status of a mycorrhizal fungi strain， which could significantly promote blueberry growth， was determined by combined morphological and molecular methods. The inoculation effect of the strain on blueberry growth was studied systematically in physiological and biochemical aspects at different growth stage. Morphological observation of 18S combined with rDNA sequencing results showed that the species is Coprinus micaceus. After inoculating the bacteria， the plant height of blueberry plantlets and acclimated seedlings were 300%， 561% higher than the control， and ratio of diameter to height of the potted seedlings was 3454% higher than the control. The hormone content of blueberry top leaves was 23 times higher than the control; and N， P absorption rate of the blueberry increased significantly by 128% and 153%, respectively. The inoculation of Coprinus micaceus strain can significantly promote the blueberry growth. In conclusion， the strain has a good application prospect， and could be preserved for agricultural production. Related Articles | Metrics

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Relationship between initial seed orientation and maize leaf spatial distribution YANG Fen\|tuan1，2， CAO Qing\|jun1， JIANG Xiao\|li1， Lamine Dallio3， LIANG Yao1， LI Gang1，* 2015, 27(3):  406.  Abstract ( 618 )   PDF (1175KB) ( 1365 )   To testify the feasibility of ordered construction of maize population and provide foundation for seeding machinery design， four experimental treatments of different oriented initial seeds in sowing season with two varieties of maize （Xianyu335， compact type with density of 75 000 plant·hm-2， and Jidan50， flat type with density of 55 000 plant·hm-2） were carried out in this study. Leaf base azimuth and ear azimuth of maize in different treatments were investigated during growth. The relationship between initial seed orientation and spatial distribution of maize leaves were analyzed. The four treatments included: （A） Seeds with embryo plane paralleled to the ground and upward. The long axis of seeds was paralleled to the direction of row， and the tip of seeds was pointed to the north; （B） Seeds with embryo plane paralleled to the ground and upward. The long axis of the seed was perpendicular to the direction of row， and the tip of seeds was pointed to the east; （C） Seeds with embryo plane perpendicular to the direction of row and faced to the north. The tip of seed position was vertically downward; （D） Random seeding. Apparently difference was found in the azimuth of leaves at plant base between different orientation treatments， but the difference was not displayed in those leaves in the upper part of plant. Leaves tended to be more perpendicular to the direction of row in treatment B， in which seeds with embryo plane were paralleled to the ground and upward， and the long axis of the seed was perpendicular to the row direction. Therefore， ordered spatial distribution of maize leaves could be achieved to a certain extent through selecting an appropriate initial seed orientation. Related Articles | Metrics

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Influence of different fertilization treatments on nitrogen and phosphorus runoff losses from seedling land JIN Shu\|quan1， CHEN Ruo\|xia1， LUO Yan2， YAO Hong\|yan1， ZHOU Jin\|bo1 2015, 27(3):  412.  Abstract ( 402 )   PDF (509KB) ( 1261 )   Aimed at the unreasonable use of chemical fertilizers in seedling land， the present research focused on the effect of different fertilization treatments on nitrogen and phosphorus runoff losses was carried out in Simingshan Town， Yuyao City， Zhejiang Province from April 26th to June 23rd， 2013， to provide theoretical basis for non\|point source pollution control in drinking water source areas. It was shown that concentrations of nitrogen and phosphorus in the first runoff after fertilizer application were higher than those in later runoff， especially in the runoff from broadcasting compound fertilizer treatment. The influence of different fertilization treatments on TN， NH+4\|N， TP， DRP runoff losses decreased in the order of broadcasting compound fertilizer＞spot application of compound fertilizer＞broadcasting controlled release fertilizer＞spot application of controlled release fertilizer＞CK. Concentrations of TN and TP in the runoff of spot application of compound fertilizer treatment were significantly lower than those in broadcasting compound fertilizer treatment. However， concentrations of TN and TP in the runoff between spot application of controlled release fertilizer treatment and broadcasting controlled release fertilizer treatment were close. Considering the environmental impact and cost， spot application of compound fertilizer and broadcasting controlled release fertilizer were two kinds of worth promoting fertilization ways in hilly seedling land. Related Articles | Metrics

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Promoting antibiotics degradation via application of organic fertilizers XU Qiu\|tong1， GU Guo\|ping2， ZHANG Ming\|kui1，* 2015, 27(3):  417.  Abstract ( 564 )   PDF (703KB) ( 1395 )   A soil culture experiment was carried out to study the effects of different organic fertilizer rates （05%， 10%） on the degradation of four antibiotics and the influence on antibiotics uptake by vegetable plants from soil. The tested four antibiotics were oxytetracycline， enrofloxacin， sulfamethazine， and tylosin， with an initial pollution concentration of 25 mg·kg-1 soil， respectively. The results showed that the application of organic fertilizer could significantly （P<005） increase antibiotics degradation in soil at early stage during the incubation experiment. The degradation rate of the antibiotics increased with increasing application amount of organic fertilizer. At the eighth day of incubation experiment， application of 1% organic fertilizer increased degradation rates of soil oxytetracycline， enrofloxacin， sulfamethazine， and tylosin， compared with those without organic fertilizer application. The degradation rates of four antibiotics decreased in the order of sulfamethazine>enrofloxacin>oxytetracycline>tylosin. Application of organic fertilizer could reduce the uptake of antibiotics by vegetable plants. Concentrations of oxytetracycline， enrofloxacin， sulfamethazine， and tylosin in plants grown in the soil with 1% organic fertilizer application were 678%， 663%， 494% and 489% lower， respectively， than those without organic fertilizer application. Compared with the control soil in which no antibiotics were added， the biomass of vegetable plants grown in the antibiotics contaminated soil declined when no organic fertilizer was applied. However， there was no significant difference in biomass of vegetable plants among the control and organic fertilizer treatments， which indicated the beneficial effects of organic fertilizers. Related Articles | Metrics

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Pollution assessment and spatial distribution of soil heavy metals in the tobacco production area in southern Shanxi XU Yue\|qi， ZHAO Ming\|qin， TAO Jin\|jiang， LI Hui 2015, 27(3):  423.  Abstract ( 403 )   PDF (1108KB) ( 1224 )   Sixty\|eight surficial soil samples were collected from the tobacco\|planting area in Pinglu County in southern Shanxi during 2012 to 2013， and Cd， Pb， Hg， As contents in these samples were analyzed. The spatial distribution of these heavy metals was studied by Geostatistics and GIS techniques to provide theoretical basis for division of cleaning tobacco\|producing areas. It was shown that the contents of these 4 heavy metals in soils were moderately spatial\|correlated. The contents of Hg and Cd were higher in the western and eastern regions， respectively. The contents of Pb and As were relatively low in the study area. The potential ecological hazard grade of heavy metals in the study area was class Ⅱ （medium hazard degree）. Among all these 4 heavy metals， the influence of Hg on local soil environment quality was the most serious. Related Articles | Metrics

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Monitoring and evaluation for heavy metals of Dendrobium officinale Kimura et Migo and its origin environment XU Li\|hong1，ZHENG Wei\|ran1，WANG Xiao\|Li1，SONG Xian\|Shui2，WU Wen\|biao3， WU Cheng\|yong4 2015, 27(3):  429.  Abstract ( 533 )   PDF (504KB) ( 1485 )   Thirty\|four artificially cultivated Dendrobium officinale Kimura et Migo samples，27 matrix samples and 16 water samples were collected from 6 towns of Yueqing including Dajing，Danxi，Hongqiao，Xianxi，Yandang and Furong. The content of Pb，Cd，Cu，Hg in these samples had been determined and their pollution status had been evaluated by both single factor comprehensive pollution index method and Nemerow pollution index method. The results showed that indexes for Dendrobium officinale Kimura et Migo were less than 06, which indicated that Dendrobium officinale Kimura et Migo had not been polluted by heavy metals，as well as the water. Analysis showed that the subatrate was clean and met the requirement for the development of pollution\|free Dendrobium officinale Kimura et Migo，but the content of Cd should be strictly controlled. The single factor comprehensive pollution index of Cd in substrate was 133，which suggested that the substrate had been slightly polluted, while the Nemerow pollution index was 097， which almost reached the warning line. Related Articles | Metrics

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Investigation and analysis of pesticide residues for commercially available fruits and vegetables in Shanghai FENG Chun\|ye1， BAO Jia\|qin1， FANG Xiao\|ming2，*， DING Zhuo\|ping1，* 2015, 27(3):  434.  Abstract ( 437 )   PDF (1319KB) ( 1232 )   In order to carry out an overall assessment of pesticide residues of agricultural products in Shanghai， the 521 samples including commercially available fruits and vegetables were detected by high performance liquid chromatography\|tandem mass spectrometry （HPLC\|MS/MS）， and the measured data was compared with the maximum residue limits （MRLs） of GB2763\|2014， European Union and Japan， respectively. The results showed that 17 kinds of pesticides were detected， among them 941% were of moderate and low toxicity. The total frequency of pesticides detected was 481 times in this survey. The pesticide residues of agricultural products in Shanghai were generally under control， 983% of commercially available fruits and vegetables were safe. However， compared with the MRLs of European Union and Japan， there is still a gap in China at present， so the standard refinement and the monitoring of pesticide residues should be reinforced to further reduce risk level and ensure the safety of agricultural products. Related Articles | Metrics

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Optimization of liquid fermentation for cellulase production by Trihoderma viride ZHAO Lian\|di1， MENG Shun\|li1， SHI Zhao\|guo1,*， ZHANG Li2， HAN Da\|yong2， LIU Hai\|xia2， XIA Pei\|qi2 2015, 27(3):  442.  Abstract ( 397 )   PDF (612KB) ( 1222 )   Taking Trihoderma viride L4C as production strain， the influences of carbon source， nitrogen source， inoculum level， incubation time， cultivation temperature and initial pH value on cellulase activity produced by liquid fermentation were studied in this paper. On the basis of single factor tests， orthogonal test was made to study the optimal liquid fermentation conditions. The results showed that the incubation time had the largest effect on the yield of cellulase. The optimal condition was listed as follows: carbon source was the mixture of straw powder and cellulose powder， nitrogen source was ammonium sulfate， inoculum level was 15%， incubation time was 5 days， cultivation temperature was 28℃， initial pH value was 50. Under this condition， the activities of CMCase and FPAase were 1 31516 U·mL-1 and 1 28277 U·mL-1， respectively. Related Articles | Metrics

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Optimization and simulation of the boat\|type board of rice direct seeder TANG Yong\|li， HE Rui\|yin， LIU Tao 2015, 27(3):  448.  Abstract ( 332 )   PDF (2618KB) ( 1203 )   In the present paper， the flow field of the liquid under the boat\|type board of rice direct seeder was simulated and analyzed via the module FLOTRAN CFX in the finite element analysis software ANSYS， and the flow line of the liquid at different section thickness was compared considering the viscosity of water and mud sliding resistance. The computation results showed that the depth of the boat\|type board exhibited varied effects to the flow field and liquid flux. Compared with the traditional test methods， the present research method would fully and directly reflect the overall flow status under the boat， and consequently save costs and improve efficiency. Under the given conditions， it was shown that a 60 mm depth of the boat\|type board had the best effects on flow field and flux. Related Articles | Metrics

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Design and optimization of LED assembled light source used for plant light supplement in greenhouse LI Zheng\|ming， YU Hui， JI Jian\|wei* 2015, 27(3):  454.  Abstract ( 312 )   PDF (1916KB) ( 1321 )   The combination of appropriate chosen red and blue LED could be a kind of light source which is similar as the absorption peak of light spectrum of plant photosynthesis and morphogenesis. It is significant to make sure the uniform distribution of irradiation of the light source. Two combinations of array were designed through the point light source model. Array 1: The proportion of red LED and blue LED was 1∶1， the array was evenly spaced. Array 2: the proportion of red LED and blue LED was 4∶1， every four red LED took the four corners of the square， and one blue LED took the center. The calculation and simulation of the TracePro software showed that: the uniformity of array 2 was better than array 1. The array 2 was progressed as follow: increase the distance of the LED array. With this progress， the uniformity of the proportion of R/B in its radiate area increased， which was beneficial for the weld of circuit board and overall heat dissipation of LED array. In order to meet the needs of supplementary lighting of plants， intensity of light was controlled through changing the working current. Modularized design could make the install， exchange and expandability rapid， and keep the uniformity of the light in the radiated area. Related Articles | Metrics

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Numerical optimization of micromixer during CPA loading for oocyte YANG Yun， ZHOU Xin\|li*， ZHOU Nan\|feng， SHAO Wen\|qi， TAO Le\|ren 2015, 27(3):  460.  Abstract ( 292 )   PDF (842KB) ( 1321 )   In order to minimize osmotic and toxic damage to oocytes during cryopreservation， microfluidic device has been applied to the continuous loading and unloading of cryoprotective agents （CPAs）. In this study，a micromixer model based on S\|shaped channel was established for the process of CPA loading， the effects of channel geometrical and operating parameters on the fluid mixing performance were investigated， and theoretical optimization was carried out for them. Results showed that the fluid mixing performance increased with the increase of height and decrease of width of the mixed channel. When the Reynolds number was in the range of 004～112， the two\|fluid was mixed only by the molecular diffusion at a laminar flow state， and with the increase of Reynolds number， the diffusion time decreased and the mixing length increased; the secondary flow from curve channel played an important role in the fluid mixing， significantly improved the mixing efficiency. Meanwhile， the curve channel will not increase local resistance of fluid flows. These conclusions have the certain reference values for the optimal design of the micro mixer and later oocyte cryopreservation experiment. Related Articles | Metrics

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Analysis on economic benefit of straw concentrated ditch\|buried returning field using machine ZHA Liang\|yu1， LI Yi\|nian1， WANG Zhao\|ye1， ZHANG Lei1， WANG Shu\|huan1，QIN Qin1， BIAN Xin\|min2，* 2015, 27(3):  467.  Abstract ( 363 )   PDF (856KB) ( 1202 )   A field experiment was carried out with three processing methods to all the straw in the field （at the rate of 210 and 105 kg·m-1 with rice and wheat straw， individually）， with ditch depth of 20 cm （D2）， 30 cm （D3） and conventional field （CK）. The relationship between cost and income and ecological compensation of wheat and rice crops from sowing to harvest was analyzed in the whole process from farmland in order to evaluate economic effect of straw concentrated ditch\|buried returning field using machine from rice\|winter wheat rotation field. The results indicated that cost input of material was 15 42380， 18 68689， 21 58556 yuan·hm-2·a-1， while the total income was 43 03824， 47 89057， 45 72198 yuan·hm-2·a-1under CK， D2 and D3 for experimental field during rice\|winter wheat rotation system， respectively. The value of ecosystem services and ecological compensation was 37 96075， 51 62185， 40 63234 yuan·hm-2·a-1and 19768， 77097， 52521 yuan·hm-2·a-1，whose economic total benefit was 27 81230， 29 97466， 24 66164 yuan·hm-2·a-1under CK， D2 and D3 during rice\|winter wheat rotation system， respectively. Straw concentrated ditch\|buried returning field using machine had a greater cost input than CK. Through the establishment of ecological compensation mechanism for ecological compensation，straw concentrated ditch\|buried returning field using machine with the depth of 20 cm had the best economic revenue and net profit. Straw concentrated ditch\|buried returning field using machine ditch with suitable ditch depth can bring higher economic benefits than that of CK. Related Articles | Metrics

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Sustainable livelihoods evaluation of reservoir resettlement from Yili Valley based on fuzzy matter\|element HUANG Xing， PU Chun\|ling*， MA Xu， YAN Zhi\|ming， LIU Zhi\|you， WEI Zhen 2015, 27(3):  477.  Abstract ( 386 )   PDF (841KB) ( 1373 )   To establish the livelihood evaluation system and quantitative standard of reservoir resettlement， the sustainable livelihoods of reservoir resettlement from Yili Valley was evaluated using fuzzy matter\|element model， together with analytic hierarchy process and statistical analysis. The results showed that the livelihood of reservoir resettlement in Yili Valley was almost the same as before， and there was still a big gap from sustainable development， this was mainly caused by the economic base and policy guarantee. Then it could be concluded that income， land output， employment， occupation skill and the local life integration affect the sustainable development of reservoir resettlement. Finally， we can promote the sustainable livelihoods of reservoir resettlement in Yili Valley through improving the mechanism of reservoir resettlement management organization， increasing the acceptance and strengthening the security system of the late stage support. Related Articles | Metrics

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Non\|linear income effect of low\|carbon products application in China： Taking solar water heater in rural area as an example MA Ben， DU Qian\|qian*， FANG Guo\|bin 2015, 27(3):  484.  Abstract ( 355 )   PDF (690KB) ( 1178 )   This paper aimed to explore the impact of income on the application of low\|carbon product in China， and non\|linear income effect was revealed by panel threshold model. Based on provincial panel data during 2004\|2010， this paper analyzed the influencing factors of solar water heater application in rural China using cross\|sectional consistency estimator. Through establishing panel threshold models， structural changes on income effect affected by natural and social economic factors were analyzed empirically. Results showed that besides income level， energy endowments， housing conditions and population mobility could also affect the application of solar water heater directly. When energy endowments， educational level， population mobility， and temperature overtook their corresponding threshold values， the income effect would experience structural change nonlinearly. Therefore， it was beneficial to improve peasants housing conditions， cultivate their energy\|saving and low\|carbon awareness， and strengthen propaganda of low\|carbon product to promote the application of solar water heater in rural China. All the suggested measures should be in accordance with rural population mobility and temperature characteristic in the process of raising peasants purchasing power. Related Articles | Metrics

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Comparison on practical patterns of rural lands cooperative shareholding systems between Jiangsu and Zhejiang CHEN Tian\|yuan， ZHANG Cheng\|qiang 2015, 27(3):  490.  Abstract ( 321 )   PDF (996KB) ( 1226 )   In the present paper， the background of the rural lands cooperative shareholding system development in Jiangsu and Zhejiang was briefly introduced as well as limitations of related studies. Then， the development status， main approaches， performances and associated problems of Wenling and Suzhou model were refined. It was found that there were noticeable differences in terms of operation types， key elements of being a shareholder， stock equity management; while there were also similarities in terms of formative motivations， basic practices， practical effects. According to the implementation status of the rural lands cooperative shareholding system， development countermeasures were proposed such as establishing linkage mechanisms between Jiangsu and Zhejiang， bolstering co\|development between rural cooperative economic organizations, strengthening internal governance structures， developing counselor training courses of rural lands cooperatives, and specializing regulations for the rural lands cooperatives. Related Articles | Metrics

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Evolutionary tendency and income gap of county residents in Yangtze River Delta： Based on Kernel density estimation method BAI Cai\|quan1，2， WANG Xiu\|mei2，3， XIE Yue\|qing2，3， ZHANG Li\|na2，3， SONG Wei\|xuan4，* 2015, 27(3):  498.  Abstract ( 381 )   PDF (570KB) ( 1236 )   Using the estimation of kernel density method， the article focused on the data of 74 counties in Yangtze River Delta from 1991 to 2011， and estimated the per capita disposable income of urban residents and the per capita net income of rural residents by nonparametric method， and on this basis， we analyzed the evolutionary tendency and income gap of county residents in Yangtze River Delta. The results proved that both the urban and rural incomes of county residents in Yangtze River Delta increased year by year. Nevertheless， whether in urban or rural areas， the income gap between high and low earners was increasing. At the same time， the income gap between high and low earners in urban residents was significantly greater than the rural residents. In addition， the income gap between the urban and rural residents was also increasing. The polarization of income distribution and the huge income gap between urban and rural residents will become one of the important reasons hindering the economy development of the Yangtze River Delta. In consequence， its necessary to adopt some measures to slow down the polarization of income distribution and narrow the income gap between urban and rural areas. Related Articles | Metrics

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A plan model of medium and small\|scale agricultural production with time flexibility （四川理工学院，四川 自贡 643000） 2015, 27(3):  504.  Abstract ( 393 )   PDF (838KB) ( 1398 )   Considering the time flexibility of agricultural production， the medium and small\|scale agricultural production plan was studied to maximize the income in the production cycle. Firstly， 0\|1 integer programming was used to build the mathematical model of agricultural production plan， which was translated into the network model based on graph theory. Then the Dijkstra algorithm was applied to solve the network model， and find the optimal strategy， namely an agricultural production plan. Finally， with the help of practical examples， the process to make an agricultural production plan was annotated. The results showed that the plan model helped to make scientific and reasonable decision for rural economic entities， such as farmers professional cooperatives， agricultural enterprises and so on. Related Articles | Metrics

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Progress on sequence variation of avirulence genes in the rice blast fungus Magnaporthe grisea JIANG Hua1， YU Huan1，2， WANG Yan\|li1， SUN Guo\|chang1，* 2015, 27(3):  512.  Abstract ( 553 )   PDF (686KB) ( 1280 )   Magnaporthe grisea is one of the most devastating pathogens of rice. The specific interaction between rice and M. grisea follows the gene\|for\|gene hypothesis， and the cognate genes in M. grisea were called AVR genes. When the corresponding host gene， known as resistance （R） genes recognize the products of the cognate AVR genes， the immune responses of rice which are always associated with hypersensitive response are trigged. During the interaction between M. grisea and its host， AVR genes always exhibit the characterization of instability. The mutation of AVR genes usually result in the loss of resistance of rice. The mutations of AVR genes involve several mechanisms， including point mutations， deletions, insertion, duplication and frame\|shift mutation. The mutation mechanisms of AVR1\|CO39， PWL， AVR\|Pita are well studied， the mutation pattern of other AVR genes including ACE1， AvrPiz\|t， AVR\|Pia， AVR\|Pii and AVR\|Pik/km/kp are less known and need further research. Related Articles | Metrics