2016 Vol. 33, No. 2

Oligomeric status of the SOC1 gene from Phyllostachys violascens and Arabidopsis thaliana
SHI Quan, CHEN Xiaopei, LIN Xinchun, XU Yonghan, XU Yingwu
2016, 33(2): 183-190. doi: 10.11833/j.issn.2095-0756.2016.02.001
[Abstract](1928) [PDF](858)
MADS-box genes are a super family, which can form different polymers to mediate the development of floral primordia and floral organs. The important one of MADs-box genes, SOC1 [suppressor of overexpression of cytochrome oxidase 1], determine the flowering time. The MADS-box transcription factor, SOC1 contains four different functions domains: MADS, I, K, and C. The K domain controls the homologous or heterologous protein polymer formation. The I domain could stabilize the MADS-box proteins binding the DNA. In order to control the floral development, MADS-box proteins can form different complex. Visible difference in floral timing is demonstrated in Phyllostachys violascens and Arabidopsis thaliana. A. thaliana is certain in floral timing while Phyllostachys violascens is not. Though we cannot compare the difference in floral timing with the difference in SOC1 complex formation, it is still interesting. MADS-box genes such as SOC1 containing four different functions: MADS, I, K and C, control floral timing. To determine whether SOC1s from different species demonstrated similar patterns in forming a complex, this study analyzed the differences of polymer formation for SOC1 that originated from Phyllostachys violascens and Arabidopsis thaliana using a yeast two-hybrid assay. Results of the assay showed that the full-length AtSOC1 gene from A. thaliana formed strong homo-polymers with the I and K domains being the main regions for formation of the interaction. However, the full-length SOC1 from Phyllostachys violascens (PvSOC1) did not form a homodimer. Thus, even though the K protein domain could form a homodimer, the presence of the I protein domain disrupted the dimer meaning the I domain could be a key factor in SOC1 polymer formation; the role of the I domain in floral timing should be verified with a plant transgene study.[Ch, 5 fig. 2 tab. 29 ref.]
Cloning of the PmPIP1 gene from Pinus massoniana and its expression with drought stress
CAI Qiong, DING Guijie, WEN Xiaopeng
2016, 33(2): 191-200. doi: 10.11833/j.issn.2095-0756.2016.02.002
[Abstract](1863) [PDF](742)
The aquaporin (AQP) gene plays an important role in plants adapting to abiotic stresses. To predict the AQP gene function and provide basal data for mechanism of Pinus massonianas drought resistance, the sequence characteristics of the AQP gene from P. massoniana were analyzed and its expression profiling was studied after drought-stress treatment. The AQP gene was cloned using reverse transcription-polymerase chain reaction (RT-PCR) and rapid-amplification of complementary deoxyribonucleic acid (cDNA) ends (RACE). The expression of the AQP gene was then performed using quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). The full-length cDNA of the AQP gene from P. massoniana, designated PmPIP1 with a registered number in GenBank KF582038, was obtained. Results of the sequence analysis showed that the size of PmPIP1 was 1 301 bp, containing an 867 bp open reading frame that encoded 288 amino acid residues with 30.86 kDa molecular weight and an 8.48 isoelectric point, a 99 bp 5 terminal untranslated regions (UTR), and a 335 bp 3 terminal UTR. The PmPIP1 3D structure had a strong similarity to Spinacia oleracea (2b5fA). PmPIP1 exhibited a typical structure with six transmembrane domains, and had the consensus sequence HINPAVTFG of membrane intrinsic protein (MIP) family and two highly conserved peptides Asn-Pro-Ala (NPA). The evolutionary analysis revealed that PmPIP1 shared a 95% identity with Picea abies and belonged to PIPs. The PmPIP1 expression patterns with drought conditions showed that drought did induce PmPIP1. In conclusion, cloning of the PmPIP1 gene from P. massoniana enriched the plant aquaporin gene database, and the RT-qPCR analysis indicated that the PmPIP1 gene may be involved in the response related to drought stress. [Ch, 8 fig. 1 tab. 39 ref.]
Identification and characterization of salt-responsive transcription factors in roots of southern type alfalfa
MA Jin, ZHENG Gang, PEI Cuiming, ZHANG Zhenya
2016, 33(2): 201-208. doi: 10.11833/j.issn.2095-0756.2016.02.003
[Abstract](1659) [PDF](764)
Transcription factors (TFs), which can regulate downstream gene expression, play an important role in plant stress responses. In order to investigate the molecular mechanism of salt tolerance, the TFs of southern type alfalfa, in this study with 250 mmolL-1 NaCl stress, Illumina RNA-sequencing was performed to evaluate the expression spectrum of transcription factors in roots of the southern alfalfa cultivar Millennium. Then to verify the expression of four randomly selected genes, Quantitative Reverse-Transcriptase Polymerase Chain Reaction (qRT-PCR)(three repeated) was used. Results showed 31 907 differentially expressed genes, 2 758 of which showed a difference of over two fold. Among these genes, 199 transcription factors belonging to 38 TF families were up-regulated and 95 were down-regulated. Genes from the MYB family were observed most, followed by AP2-EREBP, bHLH, WRKY, NAC, and GRAS. The qRT-PCR assay of four randomly selected genes confirmed the results of RNA-Seq analysis. In addition, candidate genes such as MsERF-2b,MsbHLH, MsbZIP, MsC2H2, MsGRAS, MsNAC, MsMGT-3a, and MsWRKY that may be involved in salt stress responses were identified. This study indicated that multiple TF families were involved in salt stress responses in the root of southern alfalfa types, and it provided new information for further study of the mechanism of a plants response to salt stress.[Ch, 3 fig. 3 tab. 36 ref.]
Chloromycetin effects on pigment content and chlorophyll fluorescence in Phyllostachys edulis seedlings
WU Xingbo, CHEN Dengju, MA Yuandan, GAO Yan, WEN Guosheng, ZHANG Rumin
2016, 33(2): 209-215. doi: 10.11833/j.issn.2095-0756.2016.02.004
[Abstract](1924) [PDF](536)
To determine the effects of antibiotics on plant growth, three-year-old Phyllostachys edulis seedlings were used as experimental materials. Then pigment content and chlorophyll fluorescence with different concentrations of chloromycetin (CAP) were determined using a non-modulated chlorophyll fluorometer (Yaxin-1161) and the JIP-test data analysis method. Results showed that chlorophyll a, chlorophyll b, and total chlorophyll content of the leaves significantly decreased (P<0.05) with the CAP treatment. A significant decrease (P<0.05) was found with the probability that a trapped exciton moved an electron into the electron transport chain beyond Quinone A (QA)(ET0 /TR0), with quantum yield for electron transport (ET0 /ABS), with maximum quantum yield for primary photochemistry (P0), and with performance index on absorption basis (PIABS). This suggested that CAP suppressed leaf photosynthetic characteristics. [Ch, 1 fig. 3 tab. 29 ref.]
Water vapor flux features of an evergreen and deciduous broadleaf mixed forest in Mount Tianmu area
NIU Xiaodong, JIANG Hong, FANG Chengyuan, CHEN Xiaofeng, SUN Heng
2016, 33(2): 216-224. doi: 10.11833/j.issn.2095-0756.2016.02.005
[Abstract](2366) [PDF](373)
Evapotranspiration (ET) is an important component of ecosystem water and energy balances, and subtropical evergreen and deciduous broadleaf forests play an important role in regional water cycles and budgets. To enhance prediction of climate change impact on the terrestrial ecosystem an improved understanding of the water and energy fluxes between vegetation and the atmosphere is needed. In Mount Tianmu area of Zhejiang Province, a subtropical evergreen and deciduous broadleaf mixed forest observation tower was set up in December 2012 with a three dimensional ultrasonic anemometer, a H2O/CO2 infrared analyzer, and conventional meteorological instruments for measuring a multi-layer gradient of temperature and humidity, windspeed, and radiation. Based on data observed from July 2013 to June 2014, water vapor flux features of the ecosystem were analyzed, and the net radiation responses to water vapor flux were determined. Results showed that annual water vapor flux was positive with distinct diurnal and seasonal variations. The maximum monthly water vapor flux occurred in July with a maximum daily 0.115 gm-2s-1; the lowest was in January with a maximum of only 0.029 gm-2s-1. The maximum quarterly water vapor flux occurred in summer, and the lowest was in January. The annual total ET was 721.25 mm (about 51.5% of the annual precipitation). The annual net radiation (Rn) for this ecosystem was 3 305.65 MJm-2. Also, Rn was the main driving force of ET and was a key factor in energy balance. Thus, water vapor flux being positive meant that the ecosystem was the source of water vapor. [Ch, 6 fig. 2 tab. 28 ref.]
Phytolith-occluded organic carbon accumulation and distribution in a Dendrocalamopsis oldhami bamboo stand ecosystem
YANG Jie, XIANG Tingting, JIANG Peikun, WU Jiasen, KE Hejia
2016, 33(2): 225-231. doi: 10.11833/j.issn.2095-0756.2016.02.006
[Abstract](1960) [PDF](623)
Phytolith-occluded organic carbon (PhytOC) has been shown to have an important role in carbon-silicon biogeochemical cycling. To understand the characteristics of PhytOC accumulation, different organs (leaf, branch, and culm), litter, and soil samples were collected in different age stands of 1-3 year old Dendrocalamopsis oldhami bamboo ecosystems from Cangnan County, Zhejiang Province in December 2014. Then, silicon, phytoliths, and PhytOC were analyzed with a correlation analysis. Results of silicon, phytoliths, and PhytOC mass fraction showed that PhytOC content (in gkg-1) of aboveground litter was (4.28)>leaf (3.16)>branch (0.28)>stalk (0.04). The total accumulation of PhytOC was 22.64 kghm-2 with an order (in kghm-2) of leaf (13.22)>litter (5.74)>branch (2.71)>stalk (0.96). Also, reserve stocks of PhytOC were 1 302.60 kghm-2 in the 0-100 cm soil depth. A highly significant correlation (P<0.01, R2=0.96) was found between silicon and phytolith concentration; a significant correlation (P<0.05, R2= 0.62) was revealed for phytolith and PhytOC concentration in plants; and a highly significant correlation (P<0.01, R2= 0.80) was shown with PhytOC and total organic carbon in soils. This results shows that the content of PhytOC depend on silicon and phytolith in plants, and related to total organic carbon in soils. [Ch, 4 fig. 3 tab. 33 ref.]
Climate changes affecting regional landscape patterns at Xanadu
WU Luyi, YUE Yongjie, LIU Guohou, GAO Runhong, SU Zhicheng
2016, 33(2): 232-238. doi: 10.11833/j.issn.2095-0756.2016.02.007
[Abstract](1768) [PDF](520)
To study the effects of climate change on landscape patterns at sites in Xanadu, wavelet transformation and remote sensing were used to analyze the climate change rules from 1981-2010 for landscape pattern dynamics in three different periods: 1990, 2000, and 2010. Results showed that the annual temperature had a rising tendency over the nearly 30 years with an interannual variation of 0.065a-1 years. Zone temperature changes alternated between a low frequency of 30 years and high frequency of 10 years. Annual precipitation declined slightly with interannual variation of 0.07mma-1 . The low frequency of 25 years experienced drought; whereas, the low frequency of 10 years alternated between wet and dry. Dominance of the grass landscape declined on this site. Structural landscape changes included a decrease in grasslands, water areas, wetlands, and swamps; while farmland, woodland, residential places, and sandy areas increased. For instance, sandy areas increased 9.55 km2 in nearly 20 years. Over this 30 year period, climate change was not the dominant factor that changed the landscape pattern; climate change associated with sandy and grassland areas were greatest. As regional development and relevant eco-engineering being the main factors contributing to reduce stability of these landscape sites. [Ch, 4 fig. 3 tab. 19 ref.]
Plant community and species diversity in rocky desert areas of Southern Hunan
WU Linshi, CAO Fuxiang, PENG Jiqing, CAO Jiwu, XU Yongfu, DONG Xujie, XU Wen
2016, 33(2): 239-246. doi: 10.11833/j.issn.2095-0756.2016.02.008
[Abstract](1496) [PDF](601)
The diversity of plant species in 21 plots (5 000 km2) from Southern Hunan area was determined by calculating the indices of species diversity, richness, evenness, and dominance. Analysis included and diversity analyses with the Simpson (S), Shannon-Wiener (SW), Cody (C), and Jaccard (J) Index. For rocky desert treatment and searching the regularities of growth and distribution of plant in rocky desert, applied with random quadrat sampling method and analysis by synthesis method. Results show there are overall presence of 63 families, 131 genera, and 173 species of vascular plants, 1) This included 15 families, 21 genera, and 24 species of trees; 34 families, 60 genera, and 74 species of shrubs; 32 families, 54 genera, and 63 species of herbs; 13 families, 22 genera, and 33 species of interlayer. 2) The shows that rocky desert area with low species richness (S = 0.796 9-0.936 1, SW = 2.104 7-3.274 6) and a simple community structure with individual species having a relatively uniform distribution but a higher community diversity. Species composition for the tree layer was greatest in the potential rocky desert area(S = 3.274 6 and SW = 0.936 1). At the community level, most of the trees were in the potential rocky desert. 3) The showed that environmental differences between different sample plot. The C Index revealed that, form light to severe desert area has different numbers species, the similarity coefficient of different rocky desert spot decreased. The J Index of different level rocky shows the maximum is of 7.29 times to the minium. Conclusion which plants species are suitable in rocky desertification areas, contain the expansion trend of rocky desertification, improve the environment.[Ch, 1 fig. 3 tab. 25 ref.]
Analysis on phytocoenosis association of tree species composition in ecological gardens of winter cities
YU Botao, YANG Tianqi, LI Chen
2016, 33(2): 247-256. doi: 10.11833/j.issn.2095-0756.2016.02.009
[Abstract](2213) [PDF](490)
Due to the unique climate in the winter cities, the association among tree species in these cities is special. Taking Heilongjiang province as an example, this paper surveyed the diseases and insect pests of common garden tree species, and analyzed the disease and insect pest-resistant ability of different tree species. In addition, it analyzed inter-specific association of tree species applying 2 statistical magnitude and association coefficient, and conducted research on intra-specific association of tree species as per negative density restriction effect on the same tree specie; and obtained three groups of tree species with good association and strong resistance to disease, which can be used as the basic plant communities of ecological garden. On the basis of association research, it conducted research on the optimum abundance of tree species, and obtained two tree species with significant advantages-Betula platyphylla and Fraxinus mandschurica, which can be used as the dominant tree species of ecological garden. [Ch, 2 fig. 7 tab. 22 ref.]
Soil fauna community structure in Cryptomeria fortunei artificial stands at different slope elevations in summer
XIAO Jiujin, LIN Honggui, ZHOU Xin, YOU Hua, LI Yun, ZHANG Jian
2016, 33(2): 257-264. doi: 10.11833/j.issn.2095-0756.2016.02.010
[Abstract](1787) [PDF](542)
Soil fauna, an important component of soil ecosystems, plays an important role in decomposition of biological remains, affects soil properties, and enhances material recycling and energy conversion in the soil. Understanding the impacts of slope elevation on soil fauna is essential to achieve sustainable Cryptomeria fortunei artificial stand management and biodiversity conservation; therefore, an investigation on soil fauna was carried out in Cryptomeria fortunei plantations. Three sample plots were set at three slope elevations (Plot Ⅰ-1 088 m, Plot Ⅱ-987 m, and Plot Ⅲ-830 m). Macrofauna samples (n=3) were picked up by hand in each sampled slope with the area of 50 cm 50 cm(0.25 m2). After recording the types of soil fauna, the samples were put into a container with alcohol and transported to laboratory for detailed classification to family level. Mesofauna was collected by steel core (r = 5 cm, v =100 cm3) and store in soil fauna sealing black bags. The collected samples then were transported to laboratory within 12 h and subsequently separated by Baermann method (for nematodes) and Tullgren method (for mesofauna) over a period of 48 h, respectively. All collected soil fauna were calculated and classified by microscope, and identified to the family level following Pictorial Keys to Soil Animals of China. Analysis was conducted using the following indexes: Sorenson, Morisita-Horn, Shannon-Wiener, Pielou, Simpson, and Density-groups. Results showed a total of 94 soil fauna orders belonging to 5 phyla and 13 classes with an average density of 3.46 104 individualsm-2. The density and number of groups in Plot Ⅲ at lower elevation are significant higher than that in the rest of two plots (P<0.05), and there is no significant difference between the Plots Ⅰ and Ⅱ (P>0.05). Compared to Plots Ⅰ and Ⅱ, the soil fauna density in litter layer and 10~15 cm soil layer of Plot Ⅲ is significantly higher than that in Plots Ⅰ and Ⅱ (P<0.05). The vertical study showed that more than 43% of the individuals was found in the 0-5 cm layer and more than 72% of the group number was found in the litter layer in each plot. Plot Ⅲ had the highest soil fauna density for Phylum Nematoda, and Classes Insecta, Arachnida, and Diplura. The Sorenson and Morisita-Horn indexes showed that slope elevation had a stronger effect on soil fauna density than soil fauna group type. Also, the highest Shannon-Wiener, Pielou, and Density-groups indexes were found in Plot Ⅲ at the lower elevation. Thus, slope elevation affected distribution and diversity of soil fauna in Cryptomeria fortunei plantations, and to reserve litter layer is the key to keep the soil fauna diversity. [Ch, 3 fig. 5 tab. 20 ref.]
Habitat suitability evaluation for Amur tigers in northeast China based on GIS and RS
LI Yacang, FENG Zhongke, HUANG Jixia, YANG Liu
2016, 33(2): 265-271. doi: 10.11833/j.issn.2095-0756.2016.02.011
[Abstract](2234) [PDF](607)
This article researched the habitat suitability evaluation for Amur tigers in northeast China, which found the potential distribute area and provided decision-making for the establishment of Amur tiger nature reserve and the plan of getting back to nature of artificial breeding Amur tigers. The study area in northeast China included the three provinces of northeast China and the northeast region of Inner Mongolia. According to the principles of stability, independence, dominance, and comprehensiveness, the habitat suitability of Amur tigers in northeast China was assessed using the three aspects of vegetation, geographical environment, and human disturbance with vegetation type, vegetation coverage, elevation, gradient, slope direction, water source, residential areas, and main roads selected as evaluation variables. Data for each variable was collected quantitatively using geographic information systems (GIS) and remote sensing (RS). Then the Amur tiger habitat suitability evaluation classification figure was obtained using the Analytic Hierarchy Process (AHP) method to determine the weight of each evaluation factor, and using the fuzzy mathematical model for the single factor weighted superposition. Afterward, the partitioning of areas was conducted. Results showed that human disturbance and vegetation were the main factors affecting the Amur tiger distribution. The study area was classified as most appropriate (21.97%), second suitable (16.83%), generally appropriate (22.02%), and inappropriate distribution areas (39.18%). Thus, the living space that could be appropriated for Amur tigers compared to the total potential habitat area in the Northeast China was considerable approximately 48.8%. [Ch, 3 fig. 3 tab. 25 ref.]
Kinetics of Sophora japonica embryo cells in a suspension culture system CHEN Hongxian, YU Xiaoxiao, WANG Chenyang, ZHANG Min, LIU Zhonghua
CHEN Hongxian, YU Xiaoxiao, WANG Chenyang, ZHANG Min, LIU Zhonghua
2016, 33(2): 272-279. doi: 10.11833/j.issn.2095-0756.2016.02.012
[Abstract](3880) [PDF](461)
Based on the established cell suspension culture system of Sophora japonica embryos, its kinetics was investigated. The suspension cell system of S. japonica embryos influenced by inoculum size was studied with analysis during cell culture of kinetic parameters, such as cell growth; consumption of C, N, and P; as well as changes in cell fresh weight, dry weight, and flavonoid production at various stages in the culture procedure. Results revealed that. (1) the preferable inoculum size for suspension cell proliferation was 40.000 gL-1. (2) The cell suspension culture cycle lasted about 27 d with maximum biomass in dry weight reaching 9.733 gL-1 and flavonoid production attaining 53.566 mgL-1. Flavonoid production was semi-associated with cell growth of the S. japonica embryo being negatively related from 6-12 d and positively related from 12-33 d. (3) From 0-6 d sugar, N, and phosphate were absorbed quickly; after 12 d they were more than 80% absorbed. Also, NH4+ was utilized faster than NO3-. Thus, proliferation and flavonoid production of S. japonica embryo cells was closely related to the consumption of sugar, N, and phosphate. This research could provide references for the scale-up culture of S. japonica embryos cell by bioreactor.[Ch, 10 fig. 25 ref.]
Compost and vermicompost from green wastes as substrates for vegetable seedlings cultivation
GONG Xiaoqiang, LI Suyan, LI Yan, SUN Xiangyang
2016, 33(2): 280-287. doi: 10.11833/j.issn.2095-0756.2016.02.013
[Abstract](2299) [PDF](627)
To reduce the overuse of peat and to increase the recycling rate of green wastes for vegetable seedling cultivation, the feasibility of using green waste compost and vermicompost to replace peat as a growth media was evaluated. Six media were prepared by mixing green waste compost and vermicompost with peat at different rates by volume including ck (peat), T1 (compost), T2 (vermicompost), T3 (compost + peat at 1∶1 V/V), T4 (vermicompost + peat at 1∶1 V/V), T5 (compost + vermicompost + peat at 1∶1∶1 V/V). Thereafter, three vegetable species with different salt tolerance: cabbage (most salt tolerance), lettuce (moderate salt tolerance), and zucchini (less salt tolerance) were germinated and grown in the six media. The physical and chemical properties of the different growing media were determined, and the growth of seedlings was also measured. The analysis method of subordinate function was used to evaluate the pros and cons of different growing media. All treatments were replicated ten times, in a completely randomized design. Results indicated that the physical and chemical properties of T4 were all within adequate range for use as a containerized substrate in horticulture. The comprehensive evaluation index for seedlings of T4 versus the control were higher with T4: cabbage (0.52 and 0.33), lettuce (0.52 and 0.49), and zucchini (0.54 and 0.49). Additionally, the cost with T4 was 41.56% less. Therefore, this treatment could be used successfully as a medium replacing peat for production of cabbage, lettuce, and zucchini seedlings. [Ch, 7 tab. 23 ref.]
Spatial visibility of green areas of urban greenway using the green appearance percentage
ZHAO Qing, TANG Honghui, WEI Dan, QIAN Wanhui
2016, 33(2): 288-294. doi: 10.11833/j.issn.2095-0756.2016.02.014
[Abstract](2584) [PDF](664)
To understand the spatial visibility of green areas of urban greenway in urban greenway, the green-appearance percent was used to determine and analyze green areas of greenway line 1. Through the photos took by Nikon D800, the green-appearance percent was calculated with Photoshop. Results indicated that 1) the average total green-appearance percent of greenway of four Guangzhou Districts was 31.9% with Tianhe (38.2%) > Yuexiu (36.0%) > Haizhu (26.8%) > Liwan (26.7%). 2) Using one-way ANOVA, the green-appearance percent of greenway in Tianhe District was significantly greater (P < 0.05) than Yuexiu and Liwan Districts. 3) The green-appearance percent of greenway in Yuexiu and Tianhe Districts was between 24.0% and 40.0%; Whereas, in Liwan and Haizhu Districts green areas were 10.0% to 50.0%. Thus, Yuexiu and Tianhe Districts were relatively stable providing a sustained, stable green space; but Liwan and Haizhu Districts were unstable with a discontinuous, sporadic green space. The green-appearance percent cloud be used to ecaluate the visual impact of various planning and management on urban forests.[Ch, 4 fig. 4 tab. 21 ref.]
Super absorbent resin from grafting acrylic acid onto bamboo fiber
CAO Lingyan, ZHAO Wenxiang, YU Xiaoying, DONG Congyong, JIN Zhenfu
2016, 33(2): 295-299. doi: 10.11833/j.issn.2095-0756.2016.02.015
[Abstract](1612) [PDF](497)
This study was conducted to determine the effects of the degree of neutralization with acrylic acid, the quantity of initiator and acrylic acid to use, whether bamboo fiber should be added or not, and the alkalinity of the water for a super absorbent resin. The super absorbent resin was produced by grafting acrylic acid onto bamboo fibers using potassium peroxodisulfate as an initiator. Results showed the optimum grafting conditions as the following: 60.0% monomer neutralization, 300.00 gkg-1 alkalinity from a sodium hydroxide solution, 0.04 g of potassium peroxodisulfate, and 8.0 mL acrylic acid. With optimum conditions the water absorption was about 718.20 gg-1. [Ch, 1 fig. 4 tab. 12 ref.]
Cold-setting MUF resin adhesive prepared with concentrated fomaldehyde
XI Xuedong, LEI Hong, DU Guanben, WU Zhigang, CAO Ming, LIAO Jingjing
2016, 33(2): 300-305. doi: 10.11833/j.issn.2095-0756.2016.02.016
[Abstract](11056) [PDF](551)
To research the influence of high formaldehyde concentrations on synthetic copolycondensation of melamine urea-formaldehyde (MUF) resin performance, resins from a high formaldehyde concentration (MUF-H) of 50% and standard concentration (MUF) of 37% were compared. Then glulam was prepared at room temperature (20 ℃) to test its physical and mechanical properties. Also, structural characteristics and thermal mechanical properties of resins were studied using 13C-NMR (nuclear magnetic resonance), Fourier transform infrared (FT-IR) spectroscopy, and Dynamic Mechanical Analysis (DMA). Results showed that the high formaldehyde concentrations enhanced solid content and viscosity of the MUF-H adhesive, shortened curing time, and improved shear strength for 60%. The DMA test results revealed that the MUF-H resin also greatly enhanced the adhesive elastic modulus. Additionally, the 13C-NMR analysis indicated that the methylene and ether bonds of MUF-H resin ware higher than MUF. Thus, the MUF-H system had a higher reaction rate and crosslinking degree which improved the mechanical properties of the resin.[Ch, 5 fig. 5 tab. 15 ref.]
Segmentation of wood surface knots and wormholes based on an improved LBF Model
BAI Xuebing, XU Jingtao, GUO Jingqiu, CHEN Kai
2016, 33(2): 306-314. doi: 10.11833/j.issn.2095-0756.2016.02.017
[Abstract](2028) [PDF](1971)
To make wood surface defect segmentation faster and more effective, research was conducted to put forward an improved LBF (local binary fitting) Model with image segmentation based on the Chan-Vese (CV) Model. The improved LBF Model added a new level set formulation with a linear regularization term, and at the same time formed a Gaussian function as the kernel function with two local values for fitting energy. Results showed that the improved algorithm could overcome the segmentation shortcomings in the LBF Model. Also, the segmentation process was not sensitive to the size or the position of the initial contour. However, the anti noise of the algorithm was enhanced, and the image could be segmented in non-uniform gray. The experiment showed that the algorithm completely extracted the wood surface defect images with single and multi objectives, and level set evolution corresponding to the defect image could be obtained. [Ch, 21 fig, 1 tab. 15 ref.]
Preparation and performance of novel immobilized cellulase
FU Xiaoping, YAO Shanshan, WANG Ying, GUO Ming
2016, 33(2): 315-321. doi: 10.11833/j.issn.2095-0756.2016.02.018
[Abstract](1668) [PDF](801)
A novel carrier was synthesized by condensation reaction with an acid catalytic action using tetraethyl orthosilicate and KH-560 as the silica resource and coupling reagent, respectively. The composition and structure of the carrier were characterized by infrared absorption spectroscopy, 13C nuclear magnetic resonance, and X-ray diffractometry. The novel immobilized cellulase was prepared by the crosslinking-embedding immobilized method. The enzymatic characteristics of the immobilized cellulase were tested and compared with that of free cellulase. Experimental results showed that the immobilized cellulase maintained higher activity in the broader ranges of pH and temperature. The Michaelis constant (Km) of immobilized cellulase is similar as the was 1.58 gL-1 and free cellulase was 1.40 gL-1. Thus, immobilized cellulase could have a stronger affinity, reusability, and storage stability; and could provide a reference for preparing immobilized enzymes to perform better. [Ch, 9 fig. 2 tab. 20 ref.]
Chestnut browning detected with near-infrared spectroscopy and a random-frog algorithm
ZHENG Jian, ZHOU Zhu, ZHONG Shanmin, ZENG Songwei
2016, 33(2): 322-329. doi: 10.11833/j.issn.2095-0756.2016.02.019
[Abstract](2644) [PDF](565)
To develop a calibration model for rapid, accurate and nondestructive detection of chestnut browning with peeled chestnut Castanea mollissima by using near infrared spectroscopy technology. Seventy normal chestnuts and 110 browning chestnuts were prepared, and their diffuse reflectance spectrums were collected in the wavelength range from 1 000.00 to 2 500.00 nm. Spectral pretreatment methods, including standard normal variate (SNV), multiplication scattering correction (MSC), first derivative (FD), second derivative (SD), and detrend, were used and compared first. Then random-frog algorithm was applied to select effective wavelengths (EWs) from the SNV pretreated spectrum. Afterward, a partial least squares-linear discriminant analysis (PLS-LDA) and a least squares-support vector machine (LS-SVM) model were established to classify the browning chestnuts based on EWs, and the results were compared based on sensitivity, specificity and accuracy. For the validation set, the sensitivity, specificity and accuracy obtained by EWs-LS-SVM were 0.92, 1.00 and 95.00%, respectively. The results were better than those of full-PLS-LDA model,full-LS-SVM model and EWs-PLS-LDA model. Also, the random-frog algorithm effectively selected important wavelengths and simplified the discrimination model improving precision and recognition speed. The overall results demonstrate that random-frog algorithm is a powerful tool to select the efficient variables, and EWs-LS-SVM is excellent for the spectral calibration. [Ch, 4 fig. 3 tab. 22 ref.]
Bibliometric analysis and visualization map analysis of bamboo cultivation literature
WANG Xueqin
2016, 33(2): 330-339. doi: 10.11833/j.issn.2095-0756.2016.02.020
[Abstract](1653) [PDF](591)
Literature on bamboo cultivation from the Web of Science core edition between 1980 and 2014 was analyzed with bibliometric methods. The CiteSpaceⅡ software was used to conduct a visualization map analysis of authors clustering, research institutions clustering and keywords co-occurrence from the document co-citation perspective. The results indicate that: (1)China, India, Japan and the United States of America are the main nations researching bamboo cultivation; China has the absolute advantage and holds a dominating position in this field. (2)Chinese Academy of Science, Zhejiang A F University and Chinese Academy of Forestry are the institutions with the most outputs in bamboo cultivation research, Chinese Academy of Science has the most extensive international cooperation and influence; these institutions are taking an international leading position in studying bamboo cultivation. (3)Most scholars conduct research on tissue-culture, micropropagation, plant regeneration, in-vitro flowering, somatic embryogenesis, gene and cloning, growth pattern and factors. (4)Genome sequence, phylogenetic, identification of gene are the new focus and direction for the future research.[Ch, 7 fig. 6 tab. 7 ref.]
Progresses on flower bud differentiation and flower opening in Osmanthus fragrans
WANG Ying, ZHANG Chao, FU Jianxin, ZHAO Hongbo
2016, 33(2): 340-347. doi: 10.11833/j.issn.2095-0756.2016.02.021
[Abstract](2514) [PDF](792)
Osmanthus fragrans is one of the most important ornamental plants in China. Due to the difference in the requirement to the conditions of environmental factors between flower differentiation and flower opening, these two processes are relatively independent in this species. Combining the previous references on flower bud differentiation and flower opening with our researches, we summarize the progresses on flower bud differentiation and flower opening and their environmental factors, and then simultaneously analyze the corresponding mechanism, hoping to provide an overview and useful information for approaching researches. Flower bud differentiation of one-blossom genotypes (at autumn) of O. fragrans is finished under relatively high-temperature at summer, and the relative low-temperature treatment can promote this process. The flower differentiation of autumn-blossom in multi-blossom genotypes is similar with the one-blossom ones, however the mechanism of other-season blossom is obviously different. Flowers open only after the receptivity of a certain amount of chilling at autumn. The sensitivity difference to chilling requirement among different genotypes leads to the variation of flowering time. [Ch, 2 tab. 31 ref.]
Research progress on molecular regulation mechanism of grain weight formation in wheat
WEI Wei, GUO Jialian, WAN Lintao, XU Linfeng, DING Mingquan, ZHOU Wei
2016, 33(2): 348-356. doi: 10.11833/j.issn.2095-0756.2016.02.022
[Abstract](1837) [PDF](758)
Grain weight (GW), a quantitative trait determined by several genes, is one of three key wheat yield components and is sensitive to environmental variation. Researchers at home and abroad have done many studies on the genetic traits and molecular regulation mechanism of GW formation, and have made some research progress. How to make innovations to improve unit yield of wheat based on the existing research is an important work for the researchers. In this study, the latest research progresses on components, genetic traits, genetic mapping of QTLs (quantitative trait loci, QTLs), candidate gene cloning and molecular regulation of GW in wheat were reviewed, and then the problems of existing research and the future research direction involved in our recent research were also sorted out and discussed. In order to get a comprehensive knowledge about the molecular mechanism on the production of GW, researchers should pay more attention to three key items. Firstly, the variation of hormone in the development of GW should be concerned and measured. Secondly, GWAS (genome-wide association study, GWAS) together with high throughput sequencing should be adopted to exploit SNP (single nucleotide polymorphism, SNP) markets conferring to some special agricultural trait. Finally, the candidate gene should be mapped based on SNP marker-assisted selection in the mapping population, and then the candidate genes should be cloned and their function in the regulatory network involved in the formation of GW should be covered. This work will provide a good reference for further research. [Ch, 1 tab. 52 ref.]
Scientific notes
A real-time PCR method for detection of porcine circovirus 2
YU Jing, LAO Xiujie, CHEN Yanyong, HE Xiaojiang, DAI Bing, ZHAO Ayong, WANG Xiaodu, SONG Houhui
2016, 33(2): 357-363. doi: 10.11833/j.issn.2095-0756.2016.02.023
[Abstract](2185) [PDF](704)
To develop an accurate and rapid detection method for disease screening and prevention with porcine circovirus type 2 (PCV2), a single-strand DNA virus that infects pigs, primers targeted to the ORF2 fragment of the PCV2 conserved region were designed. A real time polymerase chain reaction (PCR) method was developed using SYBR Green as a fluorescent dye and serial dilutions of ORF2 recombinant plasmid to construct a standard curve for an absolute quantification. Results showed that the detection limit was obtained with 101 copy DNA per microliter. This method exhibited 1 000 times higher sensitivity than conventional PCR, only specific identification of PCV2, and better repeatability with the less than 2% variation coefficient of intra- or inter-assay experiments. A total of 34 PCV2 positive clinical samples were confirmed using this real time PCR method, demonstrating 100% agreement in comparison with the conventional PCR having only 50% agreement. This real time PCR method could provide a valuable tool for PCV2 prevention and control.[Ch, 4 fig. 4 tab. 26 ref.]
Quantifying Botryosphaeria dothidea infection causing canker disease on Carya cathayensis using real-time PCR
ZHU Zhixiang, SHI Haojie, LEI Feibin, ZHANG Chuanqing
2016, 33(2): 364-368. doi: 10.11833/j.issn.2095-0756.2016.02.024
[Abstract](2423) [PDF](683)
Canker disease caused by Botryosphaeria dothidea is the most important disease that threaten the production of Chinese hickory and has the significant characteristics of latent infection. Therefore, the development of a quantitative detection technique of B. dothidea in hickory plants is the prerequisite for its forecasting and scientific management. In this study, specific primers were respectively designed based on the conserved regions of EF1 gene of B. dothiaea. Results of both real-time PCR and common PCR showed that the specificity and sensitivity of EFRT-F1/R1 was good primer pair. A band of 230 bp could be stably amplified by the primers EFRT-F1/R1. Further study displayed that this real-time PCR technique is more sensitive (more than 100 fold) than the common one. Our molecular detection technique will provide scientific basis for forecast, and management of hickory canker disease. [Ch, 6 fig. 8 ref.]