GONG Jing , TIAN Sha , HOU Yong , ZHAO Huanhuan , ZHU Yong
2017, 38(2):1-5. DOI: 10.7671/j.issn.1001-411X.2017.02.001
Abstract:【Objective】To investigate the diapause prevention mechanism of silkworm (Bombyx mori),and compare a series of changes of eggshell surface after diapause prevention by HCl or DMSO treatment. 【Method】The eggs were treated with HCl or DMSO at 20 and 12 h after oviposition respectively. Scanning electron microscope (SEM) was used to observe the changes of eggshell surface and aeropyle at different time points after treatment. 【Result】Both HCl and DMSO treatments successfully prevented the occurrence of egg diapause, and the average hatching rates were 93.37% and 87.81% respectively. SEM observation showed clear etching effect and “lipid” shed on eggshell surface, and the aeropyle diameter increased gradually under both treatments. The above observations were more obvious for the HCl treatment compared with the DMSO treatment. 【Conclusion】Eggshell surface changes may be related to the diapause prevention of silkworm.
LI Ting , DU Bingwang , QI Ziye , ZHANG Zhuming , WANG Zhang , ZHANG Quan , ZHANG Li
2017, 38(2):6-11. DOI: 10.7671/j.issn.1001-411X.2017.02.002
Abstract:【Objective】To provide basic data for selective breeding and improving of reproduction performance of Guinea fowl.【Method】The growth and development patterns of one to nine-week-old G. fowl were studied. Three different models including Logistic, Gompertz and Bertalanffy models were compared to identify the best model fitting G. fowl growth. 【Result】Growth traits including body mass, keel length, shank length and shank girth showed no significant differences between male and female G. fowl (P>0.05) and exhibited similar trends. The growth rate of body size was the highest with a straight ascending trend at the age of two weeks. The body mass of G. fowl was positively correlated with its body size. For male ones, the correlation coefficent (r =0.752, P<0.01) between body mass and shank length was the largest. For female ones, the correlation coefficent (r =0.600) between body mass and keel length was the largest, followed by the correlation coefficent (r =0.509) between body mass and shank length. In addition, the correlation (r =0.477) between shank length and keel length was significant (P <0.01). All three models could be used for fitting G. fowl growth, among which the Gompertz model was the best for body mass and the Bertalanffy model was the best for body size.【Conclusion】There are similar trends in growth and development of body mass and body size between male and female G. fowl. The Gompertz and Bertalanffy models are the best for fitting body mass and body size, respectively. Improving the shank length of G. fowl may help to increase its keel length, pectoral production as well as body mass.
HU Shuaishuai , WANG Wenzhou , YAN Xiaorong , ZHAO Bohao , ZHU Jie , HAO Ye , CHEN Yang , WU Xinsheng
2017, 38(2):12-17. DOI: 10.7671/j.issn.1001-411X.2017.02.003
Abstract:【Objective】To analyze Myh6 gene expression and its correlation with the muscle fiber traits of New Zealand white rabbits, and explore the role of Myh6 gene during the development of muscle fibers. 【Method】Density, area, long and short diameters for back and leg muscle fibers were measured for 2-, 4-, 6-, 8-, 10- and 12-week-old New Zealand white rabbits using the frozen section technique. Myh6 gene expressions in back and leg muscles of rabbits at different ages were estimated using qRT-PCR. The correlations between Myh6 gene expression and muscle traits were analyzed. 【Result】 The density of various muscle fibers gradually decreased, but the area, long and short diameters of muscle fibers increased from two to eight weeks, except for the short diameters of white muscle fibers increased from two to six weeks. The expression level of Myh6 gene was the highest in 4-week-old rabbit. The expression level of Myh6 gene was significantly (P <0.01) negatively correlated with the red muscle fiber area of male rabbit back muscles, and significantly (P <0.01) positively correlated with the red muscle fiber density of male rabbit leg muscles. 【Conclusion】Myh6 gene expression is closely related to type and growth of muscle fibers.
LI Qiang , XIE Shun , ZENG Songqing , LI Jie , XU Youfa , ZHANG Shen , HUANG Xianhui
2017, 38(2):18-21. DOI: 10.7671/j.issn.1001-411X.2017.02.004
Abstract:【Objective】 To investigate the pharmacokinetics and bioavailability after oral administration of the coccidiostat, robenidine hydrochloride in rabbits. 【Method】 A total of 16 healthy New Zealand white rabbits were allotted to two groups and received single intravenous administration of robenidine hydrochloride at the dose of 2.00 mg·kg-1 and single oral administration at the dose of 100.00 mg·kg-1 respectively. Blood samples were collected and analyzed by high-performance liquid chromatography (HPLC) using UV. Pharmacokinetic parameters were estimated using the WinnonlinTM software package and the curve of time and concentration was obtained using SPSS 16.0. 【Result】After i.v. injection, area under the concentration-time curve (AUC) was 1.72 μg·h·mL-1, plasma clearance (CI) was 1.17 L·h-1·kg-1, the volume of distribution was 2.87 L·kg-1 and the halflife of elimination (t1/2) was 1.72 h. After oral administration, t1/2was 8.94 h and AUC was 6.33 μg·h·mL-1. Statistical analysis showed that there were significant differences between pharmacokinetic parameters of intravenous and oral administration (P<0.05), and the bioavailability following oral administration was low (7.36%). 【Conclusion】The volume of distribution following robenidine hydrochloride was high, suggesting that the drug was widely distributed in rabbits and eliminated rapidly; Robenidine hydrochloride for oral administration was rarely absorbed into the blood or blood circulation, and the residues in vivo was low.
BA Cuiyu , ZHANG Peijun , ZHAO Fuguang , DU Xiaoyan , JIAO Xue , LI Yuehong
2017, 38(2):22-26. DOI: 10.7671/j.issn.1001-411X.2017.02.005
Abstract:【Objective】 To discover a new pathogen of Gibel carp (Carassius auratus gibelio), and to provide a theoretical basis for the disease prevention and control. 【Method】 Gibel carps suspected having hemorrhagic disease were collected from a farm in Jilin Province. Tissues were observed for bacterial infection and parasite contamination. PCR was used to detect Cyprinid herpes virus-2. Artificial infection was conducted, the infection filtrate was vaccinated to the carp epithelial tumor cells (EPC), and the EPC were observed by an electron microscope. The virus genome was analyzed by SDS-PAGE and identified by RT-PCR and sequencing. 【Result】 Neither bacterial nor parasitic infection was detected. Cyprinid herpes virus-2 specific bands were not detected by PCR. After healthy Gibel carps were infected with tissue filtrate of sick fish, the mortality rate reached 86.7% within seven days. Clear cytopathy was detected after four generations via blind passage. The virus particles were observed by an electron microscope after negative staining, the particle was spherical with around 70 nm in diameter and with no envelope. The virus was initially determined as a reovirus strain (temporarily named JL-4). The SDS-PAGE results showed that JL-4 possessed 11 segments of dsRNA, which was the typical characteristic of Aquareovirus genome. Cluster analysis for the sequences of the RT-PCR amplification product showed that S6 sequences from JL-4 and reovirus HZ08 had 99% similarity, confirming that JL-4 was reovirus. 【Conclusion】 One reovirus strain was isolated and identified from Gibel carp.
ZENG Li , HUANG Shifeng , LIU Siling , WANG Jing , LIU Jianhua
2017, 38(2):27-31. DOI: 10.7671/j.issn.1001-411X.2017.02.006
Abstract:【Objective】To understand the contamination status and antimicrobial activity of Escherichia coli in retail meat sold in Guangzhou.【Method】We collected 310 meat samples including 253 retail pork and 57 chicken meat from markets and supermarkets in Guangzhou from July to August, 2011. E.coli strains were isolated and identified using the selective media. The susceptibilities of E.coli strains to 19 common antibiotics represented by the minimum inhibitory concentrations (MIC) were tested using the agar dilution method.【Result】Totally 213 E.coli strains were isolated from 310 meat samples with the detection frequency of 68.7%, including 117 pork isolates and 36 chicken meat isolates. More than 75.0% isolates were resistant to sulfamethoxazole/trimethoprim, streptomycin and tetracycline, 10.0% to 60.0% isolates were resistant to ampicillin, nalidixic acid, chloramphenicol, neomycin, florfenicol, fosfomycin, ciprofloxacin, apramycin, enrofloxacin, gentamicin and cefazolin, and the isolates were sensitive to cefoxitin, ceftriaxone, ceftazidime, colistin and amikacin with below 5.0% being resistant strains. Isolates from chicken meat showed significantly higher resistance to cefazolin, cefoxitin, ceftriaxone, ceftazidime and fosmycin compared to pork isolates(P<0.01). There were 82.2% multi-drug resistant strains of 213 E.coli strains.【Conclusion】Retail meat sold in Guangzhou were severely contaminated by multi-drug resistant E.coli, and chicken meat isolates showed higher resistance compared to pork isolates.
BAO Lingfeng , LIN Gang , ZHAO Deming , WANG Li , HE Bing , JIANG Qingshan , ZHANG Jie
2017, 38(2):32-37. DOI: 10.7671/j.issn.1001-411X.2017.02.007
Abstract:【Objective】 To study the appropriate sowing time of different rice varieties, and ensure high quality and yield of rice. 【Method】 Six restorer lines and their 12 combinations were used as materials sowed on four dates (6 d intervals). The two-factor two-data without repeated observation model and LSD test were used to analyze differences of grain yield, grain filling stage, processing quality and appearance quality among different sowing dates and harvest periods. 【Result】 Sowing date significantly influenced brown rice rate of restorer line and had no significant effects on grain yield, grain filling period, milled rice rate, head milled rice rate, chalkiness rate and chalkiness. There was no significant difference among grain yields of II-you combinations sowed on different dates. Yixiangyou combinations were significantly influenced at the 4th period, but weren’t at the 1st-3rd period. Sowing date significantly influenced rice milling and appearance quality of hybrid combinations. Sowing delay reduced the brown rice rate, chalkiness rate and chalkiness degree, but didn’s influence the total milled rice rate and head rice rate. Harvesting delay increased the brown rice rate, chalkiness rate and chalkiness degree, but reduced the total milled rice rate and head rice rate at the 4th period. 【Conclusion】 After March 27, sowing delay significantly decreased yield of restorer lines and hybrid combinations in Southern Sichuan Province, but not the ratio of length to width. The yield most significantly decreased for rice sowed from early to middle of April. Compared with restorer lines, sowing date has more influence on filling stage, rice milling quality and appearance quality of hybrid combinations. Delaying harvest time will cause poor processing quality and appearance quality of hybrid rice grains.
ZHAO Quan , LIU Changmin , ZHANG Yu , SONG Yuxue , WANG Yu , KONG Dezhang , LIANG Chenggang , HUANG Kaifeng
2017, 38(2):38-42. DOI: 10.7671/j.issn.1001-411X.2017.02.008
Abstract:【Objective】To explore the source-sink relationship in buckwheat(Fagopyrum esculentum Moench). 【Method】The common buckwheat cultivar Fengtian 1 was selected as material. Treatment(cutting the unopened flowers and inflorescences) was conducted at the 7th day after flowering, and non-treatment was used as control. The major agronomic characteristics and metabolite contents were measured, and the grain filling process was evaluated with Richards mathematical equation. 【Result】There was no significant difference in the contents of soluble sugar and chlorophyll between sink-limiting treatment and control during the early-middle grain filling, as well as the plant height, branch number, node number at maturity. The carbohydrate accumulation was accelerated during the early-middle grain filling under sink-limiting treatment. However, there was no significant difference in the grain number per plant and grain weight per plant between sink-limiting treatment and control. Compared with control, the yield of treatment significantly decreased. The determination coefficients (R2)of treatment and control were 0.996 and 0.992 respectively, which showed that the Richards growth curve well reflected buckwheat grain filling process.【Conclusion】The Richards growth curve is suitable for estimating buckwheat grain filling process. The insufficient source or unreasonable distribution of photosynthate is an important limiting factor for buckwheat yield improvement. Adjusting photosynthate synthesis and allocation should be effective to increase buckwheat yield.
ZHANG Hongna , SU Zuanxian , CHEN Houbin
2017, 38(2):43-47. DOI: 10.7671/j.issn.1001-411X.2017.02.009
Abstract:【Objective】 To investigate the diurnal patterns and photosynthetic characteristics of the leaves of litchi (Litchi chinensis) at full-bloom stage, and provide references for cultivation and management of litchi at flowering stage.【Method】Under natural conditions, the photosynthetic parameters of three litchi cultivars including ‘Feizixiao’,‘Guiwei’ and ‘Nuomici’ at full-bloom stage were measured using a LI-6400 portable photosynthesis system. 【Result】The curves of diurnal changes in net photosynthetic rate (Pn) had two peaks and clear midday depression for all three cultivars, the first peak was measured at 10:30, and the second peak was at 13:30. The average daily Pn of ‘Nuomici’ (3.76 μmol·m-2·s-1) was significantly higher than those of ‘Feizixiao’ (2.38 μmol·m-2·s-1) and ‘Guiwei’ (2.41 μmol·m-2·s-1). Pn of three cultivars were significantly positively correlated with photosynthetic available radiation (PAR). In addition, Pn of ‘Guiwei’ was significantly positively correlated with air temperature (θa), and Pn of ‘Nuomici’ was significantly positively correlated with stomatal conductance (Gs).【Conclusion】PAR is the primary ecological factor influencing Pn of the three litchi cultivars, and the effects of other factors on photosynthesis of litchi leaves vary among different cultivars.
LIU Fang , DU Yaqin , ZHANG Lidan , FAN Xiaolin
2017, 38(2):48-54. DOI: 10.7671/j.issn.1001-411X.2017.02.010
Abstract:【Objective】 To study effects of longevity of controlled-release fertilizer (CRF) on mitigation of N2O emission from bare soil and banana-planted soil, and to provide references for further research on mitigation of N2O emission from the field.【Method】Using static chamber-GC technique, pot experiment was conducted to study N2O fluxes and cumulative emission from bare soil and banana-planted soil fertilized with CRF of 1, 3 and 5 months longevity (marked as CRF 1Mon, CRF 3Mon and CRF 5Mon respectively). 【Result】CRF longevity significantly affected the number of emission peaks, maximum emission peak flux, cumulative emissions and global warming potential of N2O from bare soil and banana-planted soil. There were 5, 3 and 3 N2O emission peaks of CRF 1Mon, CRF 3Mon and CRF 5Mon from bare soil in the middle and later stages. Maximum emission peak flux decreased in order of CRF 1Mon > CRF 3Mon > CRF 5Mon. The cumulative emissions of CRF 3Mon and CRF 5Mon were significantly lower than that of CRF 1Mon. There were 1 and 3 N2O emission peaks of CRF 1Mon and CRF 3Mon from banana-planted soil only in the early stage. N2O cumulative emissions decreased in order of CRF 1Mon>CRF 3Mon > CRF 5Mon. Prolonged CRF application was more effective on reducing N2O emission from banana-planted soil than that from bare soil. The cumulative emission decreased by 24.06% to 52.81% in bare soil, and decreased by 54.22% to 75.34% in banana-planted soil. 【Conclusion】Prolonged CRF application and crop planting can help effectively reduce soil N2O emission and the greenhouse effect.
WANG Nan , XU Junping , ZHAO Zhiyi , XU Weichen , WANG Shuai
2017, 38(2):55-62. DOI: 10.7671/j.issn.1001-411X.2017.02.011
Abstract:【Objective】To study changes in microbiological characteristics of Albic soil by regulating nitrogen application levels during the critical periods of maize growth. 【Method】 Different levels of nitrogen (0, 150, 200 and 250 kg·hm-2) were applied to the maize field. The dynamic changes in the microbial biomass carbon, microbial biomass nitrogen and the activities of urease, alkaline phosphatase, protease and catalase from typical Albic soil in mid-temperate zone of eastern China under different nitrogen levels during the maize production process were studied. 【Result】Urea application increased urease activity in Albic soil at seedling stage by activating microorganisms related with urease release. Higher nitrogen level increased alkaline phosphatase activity at seedling stage. With the growth of maize, phosphatase activity clearly decreased under different nitrogen levels, however, phosphatase activity increased with no nitrogen added. Urea addition at the initial stage was not beneficial for the improvement of catalase activity, but with the growth of maize, catalase activity increased under different nitrogen levels. At seedling stage, protease activity increased with the increase of nitrogen level, but decreased when the nitrogen level reached 250 kg·hm-2. When the maize was mature, no nitrogen or low amount of nitrogen application was more beneficial for the improvement of protease activity. Urea as a base fertilizer reduced microbial biomass carbon (MBC) content at seedling stage, while with the growth of maize, nitrogen application helped the preservation and stability of MBC. No nitrogen or excessive nitrogen application increased microbial biomass nitrogen (MBN) content, while appropriate amount of nitrogen promoted MBN to turnover and convert into available nutrients for plants.【Conclusion】The concentrated and excessive application of urea is not helpful to the preservation of soil biological fertility. Considering maize yield and soil fertility improvement, the appropriate amount of nitrogen application level in Albic soil is 200 kg·hm-2.
LI Ya , JIA Aolin , BAO Minli , XU Meirong , DENG Xiaoling
2017, 38(2):63-68. DOI: 10.7671/j.issn.1001-411X.2017.02.012
Abstract:【Objective】To study gene expression and enzyme activities of polyphenol oxidase (PPO) from periwinkle(Catharanthus roseus)infected by Candidatus Liberibacter asiaticus.【Method】The gene fragment of periwinkle PPO (PwPPO) was obtained using PCR technique. Primers were designed according to the sequence similarity of PPO genes from different species. Expression and enzyme activities of PwPPO were analyzed in leaves, center stems and roots of C. roseus infected by Ca.L. asiaticus at different days after inoculation using qRT-PCR and physiological and biochemical methods. 【Result】The expressions of PwPPO were upregulated 4.23, 12.64 and 33.80 fold respectively in leaves, center stems and roots at 30, 35 and 40 days after inoculation. The time and extent of the upregulated expressions of PwPPO in different tissues were different. The PPO activities in leaves, center stems and roots of periwinkle infected by Ca. L. asiaticus were 2.87, 2.10 and 1.89 times respectively of healthy control at 30, 35 and 45 days after inoculation respectively. 【Conclusion】Gene expression level of PwPPO is proportional to PPO activity, and is related closely to the resistance ability of host periwinkle against Ca. L. asiaticus invasion.
YANG Meiying , LU Dongxue , SUN Hemei , WU Zhihai , YUE Shengtian , FU Li
2017, 38(2):69-74. DOI: 10.7671/j.issn.1001-411X.2017.02.013
Abstract:【Objective】To clone and identify GADH small subunit gene ga2dh. 【Method】 Changes in soluble phosphorus content, GADH activity and ga2dh gene expression level during the phosphate solubilizing process of Serratia sp. NDW3 from rice rhizosphere were studied. The ga2dh gene was cloned and expressed in Escherichia coli BL21, and bioinformatic analysis was performed. 【Result】The relative expression of ga2dh gene in the process of phosphate solubilizing by Serratia sp.NDW3 reached maximum at 12 h, GADH activity reached maximum at 24 h, and the soluble phosphorus content stabilized after 36 h. The ga2dh gene sequence of 781 bp was obtained from Serratia sp.NDW3 by cloning. The similarity between ga2dh gene and Serratia sp.SCBI sequences was 99.62% based on bioinformatic analysis. The protein encoded by ga2dh belonged to the superfamily of gluconate dehydrogenase subunit 3 and was composed of three α-helices. The amino acid sequence was consisted of intracellular, extracellular and transmembrane regions. The expression of ga2dh gene in E.coli BL21 significantly increased GADH activity. 【Conclusion】The main mechanism of phosphate solubilizing by Serratia sp. NDW3 is through the direct oxidation pathway. The small subunit encoded by ga2dh gene not only plays an important role in GADH activation, but also is part of the transmembrane structure of GADH.
LIU Huan , DENG Shuzhen , ZHAO Xiaofeng , CAO Fengqin , LU Yongyue
2017, 38(2):75-80. DOI: 10.7671/j.issn.1001-411X.2017.02.014
Abstract:【Objective】To study the external morphology, internal microstructure and photoreception mechanism of compound eye of the oriental fruit fly (Bactrocera dorsalis).【Method】The external morphology of compound eye of B. dorsalis adult was observed using a scanning electron microscope. The microstructure of compound eye and the structural change of ommatidia under different monochromatic lights were observed using histological biopsy.【Result】The compound eyes were hemispheric, smooth, and located on the lateral upside of head. The gaps among ommatidia were covered with interommatidial hairs. Each ommatidium was comprised of a cornea, a crystalline cone, retinula cells, a rhabdom and a basement membrane. There were abundant pigment granules in the retinular pigment cells, and in the surroundings of the crystalline cone and rhabdom. The pigment granules in accessory pigment cells moved longitudinally under different monochromatic lights. They were distributed uniformly along the longitudinal axis in the ommatidium under white, green and yellow light, while mainly clustered in the distal of retinular cells and proximal of cornea under violet, blue and red light.【Conclusion】There are no difference in external morphology and internal microstructure of compound eyes between male and female of B. dorsalis, and the compound eyes of both sexes are apposition eyes. Their compound eye adapts to environmental light changes by the mechanism of pigment granules moving longitudinally. This research can provide a theoretical basis for screening sensitive lights of B. dorsalis adult for light trapping.
MENG Hengling , ZHANG Wei , LU Bingyue , SU Yilan , XUE Chunli
2017, 38(2):81-85. DOI: 10.7671/j.issn.1001-411X.2017.02.015
Abstract:【Objective】 To clone soluble acid invertase (SAI) gene in Dendrobium officinale, and perform bioinformatics and spatio-temporal expression analysis.【Method】The full length cDNA of SAI gene in D. officinale was cloned based on homologous sequences, the sequences were analyzed using bioinformatics tools, and the tissue-specific expressions were analyzed using qRT-PCR. 【Result】 The full length SAI gene in D. officinale is 1 595 bp, the full length cDNA is 1 368 bp, and the Genbank accession number is KU598852.The SAI gene encodes 455 amino acids, and the protein molecular mass is 50 700. NCBI BLASTx results show that the D. officinale acid invertase gene has 77% similarity with Citrus unshiu acid invertase gene and C. sinensis acid beta-fructofuranosidase gene, and has above 68% similarity with acid invertase genes from other plants. Cluster analysis shows that D. officinale acid invertase gene has the closest genetic relationship with Zea mays vacuolar invertase gene and sugarcane (Saccharum officinarum) SAI gene. The encoded protein of D. officinale SAI gene is positioned in vacuole, and is a hydrophilic, non-transmembrane and heat-stable protein. RT-PCR results showed that the expression level of SAI gene was the highest in 2-year-old D. officinale stems, and the lowest in 3-year-old D. officinale leaves.【Conclusion】 The cloned gene is identified as the D. officinale vacuolar SAI gene. Its expression has great differences among different tissues and at different developmental stages.
CUI Huliang , HUANG Nongzhang , YAN Haichuan , LIU Jianxin
2017, 38(2):86-91. DOI: 10.7671/j.issn.1001-411X.2017.02.016
Abstract:【Objective】To analyze the variation of main phenotypic traits and yield per plant of oil peony (Paeonia suffruticosa), study the correlation between yield per plant and phenotypic traits, and determine the components of yield per plant.【Method】Twenty five peony varieties were selected. Correlation analysis, principal component analysis, multiple regression analysis and path analysis were performed on their main phenotypic traits. 【Result】The variation coefficients of all the investigated phenotypic traits ranged from 11.36% to 82.57%. Yield per plant was significantly(P<0.01) positively correlated with 10 traits including fruit mass per plant, fruit number per plant,valid fruit number per plant, seed rate, follicle width, crown area, new branch number per plant, two-year-old branch number per plant, flower number per plant and leaflet number. Yield per plant was significantly (P<0.05) positively correlated with three traits including aggregate follicle diameter, compound leaf width and compound leaf length to petiole length ratio. Yield per plant was significantly(P<0.05) negatively correlated with three traits including seed moisture content, top leaflet length and top leaflet shape index.The principal component analysis showed that there were five common factors with eigen values above 1, and the accumulative contribution rate was 69%. The multiple linear regression analysis and path analysis showed that yield per plant was significantly correlated with six traits including fruit mass per plant, fruit number per plant, valid fruit number per plant, seed rate, thousand-seed mass and top leaflet shape index. 【Conclusion】The key traits influencing yield per plant of oil peony in order were fruit mass per plant, valid fruit number per plant and seed rate. The three traits should be paid more attention in oil peony breeding and germplasm innovation.
CHU Shuangshuang , WANG Jing , TONG Xin , CHEN Xiaoyang , DENG Xiaomei , LIN Jiayi , ZENG Shucai
2017, 38(2):92-98. DOI: 10.7671/j.issn.1001-411X.2017.02.017
Abstract:【Objective】To explore effects of combined application of organic and chemical fertilizers on growth of young Neolamarckia cadamba plantation(YNCP).【Method】Impacts of combined application of pig manure, chicken manure, calcium superphosphate and potassium chloride on YNCP growth were studied by using orthogonal test.【Result】Combined application of organic and inorganic fertilizers had significant promoting effects on YNCPW growth, with height and ground diameter growth of fertilized treatments being 23.53% -109.41% and 37.99%-149.06% greater than those of control treatment, respectively. Multivariate analysis indicated that pig manure and calcium superphosphate had significant effects on height and ground diameter growth, and differences among different fertilization levels were significant, but chicken manure and potassium chloride exhibited no significant effect. According to YNCP growth and fertilizer cost, the best fertilization solution was 14 kg pig manure+1.5 kg calcium superphosphate per tree. The regression equation between pig manure (x1), calcium superphosphate(x2) and tree height (yH) was yH=1.016+0.031x1+0.221x2(R2=0.835, P=0.000), and the regression equation between pig manure, calcium superphosphate and ground diameter (yD) was yD=26.193+0.991x1+6.052x2(R2=0.83, P=0.000). 【Conclusion】Combined application of organic and inorganic fertilizers can significantly promote YNCP growth, and 14 kg pig manure + 1.5 kg calcium superphosphate per tree have the best promoting effect.
TAN Weizheng , XU Hualin , CHEN Yimin , ZHAO Wanyi , ZAN Qijie , LIAO Wenbo
2017, 38(2):99-105. DOI: 10.7671/j.issn.1001-411X.2017.02.018
Abstract:【Objective】 To reveal the succession of vegetation in Neilingding Island, and provide a scientific basis for protection of Artocarpus hypargyreus, a rare and endangered species endemic to China. 【Method】Method in community ecology was used to survey the sample plots of A. hypargyreus community in Neilingding Island, Guangdong. The community composition and structure, characteristics of geographical components and species diversity were analyzed, and were compared to those of other three plant communities in tropic or mid-subtropical regions.【Result】A total of 73 species of vascular plants belonging to 61 genera of 40 families were discovered in the A. hypargyreus community.Among them, 4 species of pteridophyta belong to 4 genera of 6 families, and 69 species of seed plants belong to 57 genera of 36 families. Tropical genera (98.18%) occupied a foremost position in this community which shows a transitional property that range from south subtropical to tropical regions. The stratification of the community was obvious: the dominant populations in the arborous layer mainly were Pterospermum heterophyllum, A. hypargyreus, Litsea monopetala and Machilus chekiangensis, with the important values of 43.86, 31.64, 12.75 and 10.39 respectively, the dominant population in the shrub layer mainly were Microcos paniculata and Psychotria rubra , and the lianas were abundant among the layers. The dominant populations in this community had clustering distribution pattern, and were characterized by stumpage of level II (DBH<2.5 cm) and level III (2.5 cm≤DBH<7.5 cm), indicating that they belonged to the increasing population except the A. hypargyreus population was declining. In this community, Simpson diversity index (E) was 0.95, Shannon-Wiener diversity index (H) was 3.27, and Pielou evenness index (EH) was 0.84. 【Conclusion】The A. hypargyreus community in Neilingding Island is a south subtropical evergreen broad-leaved forest at the middle stage of succession.
OU Yongxin , WENG Shufei , FENG Jiayi , LI Biru
2017, 38(2):106-111. DOI: 10.7671/j.issn.1001-411X.2017.02.019
Abstract:【Objective】Closing process of landscape trees in South China was studied in two years after pruning, in order to explore the closure mechanism of pruning wounds, and provide a theoretical basis for landscape tree pruning practice.【Method】Branches in three sizes from five species of landscape trees were trimmed in December 2013. Measurements of the wound closing process were taken every three months from December 2014 to December 2015. Differences in wound closure abilities caused by species characteristics, wound sizes and seasonal changes were analyzed.【Result】The wound closure rates of Michelia alba and Mangifera indica were relatively higher (94.80% and 92.38%) compared to other species,and the wounds of 20-<30 mm and 30-<40 mm diameters closed faster compared to 10-<20 mm wounds. The wound closure rates of Syzygium jambos, Bauhinia variegata and Ficus virens were relatively lower (82.23%, 64.95% and 70.99%), and the wounds of 10-<20 mm diameter closed faster. The wound closure process was generally slow from the time of pruning to March, accelerated from March to June, was the fastest from June to September, and slowed down from September to December in the first year, which was consistent with the changes in tree growth rates during annual growth periods. The wound closure process was slow in the second year. 【Conclusion】 Wound size influences wound closure rate differentially among species. Wound closure rate is closely associated with the tree growth rate.
YANG Liu , YU Pingxiang , HU Yueming , CHEN Liancheng , ZHANG Feiyang
2017, 38(2):112-117. DOI: 10.7671/j.issn.1001-411X.2017.02.020
Abstract:【Objective】Concentrated connectivity is the propulsion in current farmland consolidation, and concentrated connectivity threshold has a direct effect on engineering cost. This research focuses on studying the adjustment method of concentrated connectivity threshold based on landscape ecological indexes.【Method】Five landscape ecological indexes, which were obtained based on special processing functions in GIS platform,were used to achieve the quantitative evaluation of farmland connectivity. Based on the buffer function in GIS platform,the changes of farmland connectivity were simulated by setting different threshold dx. The curve of farmland connectivity was observed when the threshold dx was changing, and the optimal connectivity threshold d0 was identified.【Result】Taking farmland in Luoding City, Guangdong Province as an example, when the consolidation threshold ranged from 0 to 50 m, the optimal connectivity threshold d0 was 12 m. The farmlands, which separated less than or equal to 12 m, should be connected. As the experiment was repeated in Gaoming District of Foshan City, the optimal connectivity threshold was also found, which testified the feasibility of this method.【Conclusion】The method, which finds the optimal connectivity threshold based on landscape ecological indexes, is straightforward, reliable and pervasive, and can provide the technical reference for national farmland consolidation.
XU Peipei , WAN Xuefen , YANG Yi , HAN Fang , JIANG Xueqin , HU Chenfei
2017, 38(2):118-124. DOI: 10.7671/j.issn.1001-411X.2017.02.021
Abstract:【Objective】 To design hybrid wireless sensor network nodes for the field managements and tourist services of tourism-agriculture. 【Method】 Node hardware structure and mobile APP based on Android system for smart devices were designed. The planting environment was monitored and equipments were controlled by communication between host computer and ZigBee.【Result】 Tourists and field managers could quickly access the nodes in the field based on near field communication(NFC)and bluetooth techniques, and could get location, planting information, environmental monitoring and other services via the mobile devices.【Conclusion】 The hybrid wireless sensor network nodes are flexible, convenient and fast with good expansibility, and can more flexibly support multi-service engineering in tourism-agriculture.
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