2008 Vol. 25, No. 3
To probe optimal combing technologies and to design and manufacture the best possible rolls for a combing machine, sawmill slabs of Chinese fir(Cunninghamia lanceolata) were rolled radially without in cross direction. Thickness, moisture content, and compression rate were studied by forming combing processing blank using rolling pressure. Results showed that 1) thickness, moisture content, and compression rate with better rolling pressure technology meant a compression rate and moisture content about 50%. Also, 2) after rolled pressure treatment, the thickness of the slab decreased and the width increased. In addition, 3) after rolled pressure, Chinese fir cells had various distortions, for instance cell compress and a diminished cell cavity, but the cell wall was not destroyed, nevertheless, later most of the cells returned to normal.
A method for the detection of defects in the wood surface by grey histogram, which was analyzed by 25 grades for every 4×4 block pixels, was studied in the research. It judged the existence of defects in the woods according to the color break in grey-histogram. Defect pictures had double peaks in the grey-histogram and usually the subordinate peak was the defect part. However, the influential factors including motley and texture were not considered during the first step. The subordinate peak and host peak values were compared to eliminate the disturbance caused by motley. The research findings showed that the subordinate peak value indicated defect color if it was 1/10 times greater than the value of the host peak. Meanwhile, the disturbance caused by texture could also be eliminated through histogram amendment.
Dynamic bending modulus of elasticity of Mongolia scotch pine(Pinus sylvestris var. mongolica) full dimension lumber(38 mm×89 mm×4 000 mm) and Chinese fir (Cunninghamia lanceolata) plantation dimension lumber (45 mm×90 mm×2 500 mm) were tested by three non-destructive techniques, i.e. transverse vibration method, longitudinal fundamental frequency vibration method and ultrasonic wave method. At the same time, the static modulus elasticity of the above specimens were tested according to ASTM D198-99. The results showed that the value of dynamic and static modulus of elasticity followed the sequence as the following, Eusw > Efr > Etru > Etv, the relationship between dynamic and static modulus of elasticity concerning the three methods was significant at 0.01 level, indicating that all the three nondestructive methods could be used to predict the bending properties of dimension lumber. Furthermore, considering the operation of the equipment, longitudinal fundamental frequency vibration technique was the most accurate, convenient, reliable, easy and practical method. It was also found that the coefficient of determination(R2) obtained by using the three nondestructive techniques for Chinese fir plantation full dimension lumber was lower than that of Mongolia scotch pine full dimension lumber, estimating the static modulus elasticity of Mongolia scotch pine was more accurate than that of plantation Chinese fir.
To understand the growth strategies of clonal ramets from Rhus typhina, an exotic tree species, in the shrub-grassland of the hilly area of the Taihang Mountains in north China, a relevant analysis was conducted on the heterogeneous growth characteristics of R. typhina clonal ramets in two different habitats, farmland and shrub-grassland, using a continuous quadrat method. The major results for clonal ramets of R. typhina were as follows:1) the front part of the lateral root diameter was two times larger than the back, and growth rates of crown width were faster than the height;2) there was a power function relationship for crown width and tree height, with the heterogeneous growth of the front and back parts of the lateral root diameter more stable on farmland than in the shrub-grassland; and 3) ramets on farmland were 31 times greater than in the shrub-grassland ecotype. A growth strategy with much faster lateral branch and leaf growth than tree height, enabled clonal ramets of R. typhina to form a dominant synusium resulting in gradual disappearance of the native deciduous shrub and grass synusiums.
The effects of polyethylene glycol(PEG) 6000 osmotic treatments on germination of Pinus tabulaeformis seeds were studied through an orthogonal design(L934, L1645). Seeds harvested in 2002 had differing water content, and seeds harvested in 2004 were artificially aged(40 ℃, 100%RH) to different time periods. These seeds were then subjected to different pretreatment combinations of PEG solution level, treatment duration, and temperature. Next, seeds were germinated on a cotton bed, and the germination rate, germination index(GI=∑Gt(germination rate in certain days) /Dt(number of germination days) ), and vigor index(VI=GI/fresh weight of seedling) were statistically analyzed. Seeds harvested in 2002 had a water content of either 9.84% or 6.03%, were treated with a 200 g·kg-1 PEG solution, and had a treatment time of 1 d; seeds harvested in 2004 were artificially aged 0 d, were treated with a 200 g·kg-1 PEG solution, had a treatment temperature of 25 ℃, and a treatment duration of 2 d. The seed germination rate was higher(P<0.05) after treatment and seeds sprouted synchronously. The range of water content for seed germination was wide with seed germination being inhibited at lower seed water content. Seed vigor decreases due to natural aging that were simulated with artificial aging were restored with PEG treatment of the artificially aged seeds. The different content, treatment duration, and temperature of the PEG solution had a definite influence on the seeds with the PEG treatments, overall, helpful for Chinese pine seed germination.
Genetic improvement for target traits(flower head diameter, ray floret length, ray floret breadth, ray floret number and tubular disk floret number) in chrysanthemum (Dendranthema×grandiflora) was undertaken by determining the nature and amount of variability present in genotypes and the extent to which the desirable traits were heritable, as is commonly used in agronomic crops. A field experiment was conducted in Nanjing, from June 2006 to January 2007 (1) to assess the extent and pattern of diversity for 52 cut-chrysanthemum genotypes with emphasis on inflorescence traits as well as (2) to estimate their heritability in broad sense (h2B) and genetic advance from selection of the different traits using variance and correlation analysis. Results showed that the phenotypic coefficient of variability ranged from 28.66% for flower head diameter to 82.63% for ray floret number, whereas the genotypic coefficient of variability varied from 28.20% for flower diameter to 82.10% for ray floret number. Generally, the phenotypic coefficient of variability was a little higher than genotypic coefficient of variability for each trait. All inflorescence traits exhibited considerably high h2B(>96%).The highest two h2Bwere ray floret number(99.36%) and tubular disk floret number(99.07%), and there was a high genetic advance of 168.59% for ray floret number and 149.42% for tubular disk floret number. This indicated the presence of additive gene action, which suggested that direct selection was suitable for improvement of these two traits. A correlation analysis revealed a highly significant correlation (P<0.01) among the inflorescence traits investigated.
This study dealt with optimization of amplified fragment length polymorphism(AFLP) analysis based on the high quality DNA extracted by the improved cetyl trimethyl ammonium bromide (CTAB) method from the leaves of Lagerstroemia indica,L.subcostata, L. limii and L. guilinensis which were gathered in Guangxi, Yunnan and Henan Province. And their DNA were used as the template to carry on restriction-ligase reaction, then the product was diluted the certain multiple as template to take pre-amplification, finally the product was diluted and used as template to carry on selective amplification, and the best system of restriction-ligase reaction, pre-amplication and silver staining suit for L.indica had been optimized. In the AFLP system each step of response had established different reacting system. The 10 pairs of primer suit for L.indica were selected from 160 pairs of elementary primer. The result indicated that, the best systems suitable for the Lagerstroemia gene group were as follows: restriction-ligase reaction system 1; pre-amplification system 3; selective amplification system 3, in reacting system the best Mg2+ concentration was 1.2×10-6 kg·L-1.
Ostrya rehderiana is under first class national in China, only distributing in National Nature Reserve of Mount Tianmu, Zhejiang Province, and having only five wild trees(namely No.1,No.2,No.3,No.4, and No.5) in the world. The five trees were fingerprinted using random amplified polymorphic DNA(RAPD) markers with 18 primers being screened. A total of 176 DNA base pair(bp) fragments ranging from 200 bp to 2 800 bp were amplified with 88 of these bands being polymorphic(50%). Based on genetic distances, relationships among the five individuals were constructed using Unweighted Pair Group Method with Arithmetic Mean(UPGMA). Genetic distance positively correlated with geographic distance. Because No.1 was located further from the other four, it was clustered into one group alone. Therefore, more attention should be given to the tree of No.1
To explain the genetic relationship and genetic diversity of Houttuynia cordata, 24 samples from throughout China were analyzed using polymerase chain reaction(PCR) with random amplified polymorphic DNA(RAPD) molecular markers having 23 polymorphic primers screened from 160 RAPD primers. Then a cluster analysis was conducted. Results showed that 128 polymorphic bands were determined from the 165 clear bands accounting for 77.58%. From each primer, with an average of 7.1 bands, 5.5 polymorphic bands were amplified. The cluster analysis divided samples into 3 types according to their genetic distance, which got the same result with their morphological and biological characteristics. Thus, genetic diversity was high within H. cordata. These results will lay a theoretical foundation for breeding new varieties of H. cordata.
To understand drought tolerance in Mucuna sempervirens, physiological and morphological expression studies were done on three species of liana(Hedera nepalensis var. sinensis, and Euonymus fortunei) with polyethylene glycol(PEG) 6000 concentrations of 50 g·L-1 and 200 g·L-1 for 0(the control), 1, 3, and 5 d. All of the samples were two-year-old seedlings. Results showed that leaf water content and the rate of dehydration decreased, but water saturation deficit, electrolyte leakage, and free proline increased significantly(PM. sempervirens was significantly(PH. nepalensis var. sinensis and E. fortunei. Synthesize all of the indexes, drought resistance of the three lianas was E. fortunei > M. sempervirens > H. nepalensis var. sinensis. During the stressed period, proline content and SOD activity of M. sempervirens increased to resist drought and protect the cell membranes.
Growth, ion uptake, and transport of two (Taxodium distichum×T. mucronatum)×T.mucronatum ‘Zhongshansha’ breeding clones, No.146 (with relatively strong salt resistance) and No.24 (with relatively weak salt resistance), were compared under hydroponic culture conditions. A pot experiment design with treatments of clones (No.24 and No.146), NaCl concentrations of (3.0, 3.5, 4.0, and 4.5 g·L-1 with a control of 0 g·L-1), and five replication. Results indicated that compared with the control, total dry mass and aboveground weights of the two T. ‘Zhongshansa’ breeding clones treated with NaCl decreased. Other results included: 1) root dry mass of No.24 decreased significantly(PP-1); 2) compared with the control, the root-shoot ratio increment of No.146 treated with NaCl at lower concentrations (3.5 g·L-1) was larger than No.24; 3) relative growth of No.146 decreased at lower concentrations (3.0 and 3.5 g·L-1), but not as much as at high concentrations; and the relative growth of No.24 was opposite of No.146. In treatments with NaCl, root selectivity toward K+ of No.146 was stronger significantly(P+ in leaves and the Na+/K+ value of No.146 were lower significantly(P+ were important reasons why clone No.146 had a stronger salt resistance.
To explore the association between dominant plant populations, the interspecific associations of dominant tree and shrub populations together with niche plants in an evergreen broadleaf forest of Shiyang Forestry Center, Zhejiang Province were studied based on a 2×2 contingency table using percentage of co-occurrence(C) and association coefficient(D). Results showed that in the tree layer Schima superba, Cyclobalanopsis glauca, Rhododendron ovatum, and Rhododendron latoucheae had higher associations with a majority of the other populations, whereas as Carpinus viminea, Symplocos stellaris, Choerospondias axillaris, Neolitsea aurata, Castanopsis tibetana, and other species had relatively weak associations. Nevertheless, the entire community was relatively stable. In the shrub layer 83.4% of the total 253 species pairs, had a co-occurrence of less than 10%, while 59.3% had association coefficients(D) less than -30%. Most of the shrub species pairs showed weak or no interspecific association. Also, greater intensities of association had larger niche overlap values, whereas weaker associations had smaller niche overlaps.
The habitat of forest musk deer(Moschus berezovskii) in Fengxian County,Shaanxi Province, was analyzed using remote sensing(RS), geographic information system(GIS) and Fragstats. With the model of landscape connectivity, constructed on the fuzzy evaluation of connectivity, several aspects such as the connectivity level,suitability assessment and fragmentation status of the musk deer habitat in the area were analyzed, and a habitat model of forest musk deer was built up. The results showed that the most suitable areas for the forest musk deer covered 168 km2, only 5.28% of all the research area (3 187 km2). The most suitable areas were extremely fragmentized. According to the related landscape index, the most suitable areas were all small in the region, narrow and long in figure and separated from each other. All the results showed that the habitat was not suitable for the further development of the musk deer population.
In order to monitor the carbon sink of Cunninghamia lanceolata(Chinese fir) in the key fir production area of Zhejiang Province, the research integrated previous research achievements such as site quantified model, quantitative thinning technology, yield models and biomass models to establish a methodology for monitoring Chinese fir carbon sink to predict the carbon density, carbon storage and net carbon dioxide absorption amount of Chinese fir stand. The monitoring methodology was divided into two stages, i.e., project programming stage and stand growth stage, to predict the above-mentioned three indexes. The research selected the easily determined carbon pool as monitoring object and used conventional measurement factor to predict the biomass and carbon sink amount which are difficult to measure. The monitoring methodology is not only scientific, accurate, and effective and quick, but also cheap and efficient.
To improve ecological restoration of soil physical properties, soil hydrology, before and after application of four ecological restoration measures(afforestation on barren slopes, supplemental plantings on open forest land, prohibiting access to terraced slopes being revegetated, and prohibiting access to barren slopes being revegetated) was studied in central Shandong Province with typical sample plot method for three replication. Then infiltration models including Horton's infiltration model, and universal infiltration model were tested to determine the best model. Results showed that with all four restoration measures the average fine-grained soil particles increased 9.44%, average sand content was a low 9.45%, soil fractal dimension increased about 1.7%, soil porosity increased 6.8 mm, soil density was a low 0.63 g·cm-3, soil water-holding increased, and soil infiltration increased about 1.32 mm·min-1. Improvement was greatest for afforestation on barren slopes, intermediate for both supplemental planting on open forest land and prohibiting access to terraced slopes being revegetated, and lowest with prohibiting access to barren slopes being revegetated. With each ecological restoration type the Horton infiltration model was superior.
Microcapsules of glyphosate were made by the method of in-situ polymerization with urea-formaldehyde resin as the outer membrane. The effects of reaction parameters on particle size, distribution and structure were studied. Encapsulation efficiency and controlled release were characterized. Optimal reaction conditions were as follows: acidification time being 4 h, endpoint pH being 2.0, curing temperature being 70 ℃, curing time being 2 h, mixing rate being 2 000 r·min-1, acid catalyst being NH4Cl and suitable emulsion being styrene maleic anhydride(SMA). Under those conditions, solid, spherical microcapsules were formed with decentralization of 1-10 μm, the encapsulation efficiency was 91.9% and it had excellent controlled release properties. These results suggested that the microcapsules could fully meet the needs of practical applications.
The last research showed the husk of Carya cathayensis contained compounds which can control fungi and bacteries. The antifungal and antibacterial activity of methanol extract from the husk of Carya cathayensis was tested with Botrytis cinerea, Alternaria solani, Fusarium oxysporum f.cucumerinum, Colletotrichum lagenarium, Fusarium oxysporum f.vasinfectum, Pyricularia oryzae, Exserohilum turcicum, Bipolaris maydis, Valsa mali, Fusarium graminerum, Rhizoctinia solani, Sclerotinia sclerotiorum, Sclerotinia sclerotiorum, Venturia nashicola and Phytophora capsici by growth speed rate method. Results showed that the extract from the husk of Carya cathayensis in a concentration of 100 g·L-1 had 100% inhibition rates on hyphae growth of Colletotrichum lagenarium, Sclerotinia sclerotiorum, Valsa mali, Phytophthora capsici, whereas, except Bipolaris maydis, there was greater than 69% inhibition rates on the other 10 fungi. The virulence test for six of the 15(Sclerotinia sclerotiorum,Fusarium graminerum,Rhizoctinia solani, Pyricularia oryzae, Exserohilum turcicum, Botrytis cinerea) tested plant pathogens showed that the antifungal activity of the methanol extract from the husk of C. cathayensis was the highest against Rhizoctinia solan with a median effective concentration required to induce a 50% effect (CE50) of 29.8 g·L-1; next was against Botrytis cinerea(CE50 of 31.1 g·L-1), and the lowest was against Exserohilum turcicum(CE50 of 46.2 g·L-1). Thus, research and development of botanical fungicides using the husk of Carya cathayensis should be studied further.
The antimicrobial activity of ethanol, acetone, and aqueous extracts from Pinus massoniana needles on four bacteria(Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Sarcina ventriculi) and three mold fungi(Trichoderma viride, Penicillium chrysogenum, and Aspergillus niger) was evaluated by agar-diffusion bioassasy. Filter paper discs impregnated with extracts at concentrations of 100.0, 50.0, 25.0, 12.5, 6.3, 3.1, 1.6 g·L-1 were placed on the agar surface. Reversal of the antiviral activity of mycophenolic acid was indicated by virus breakthrough in those cells in close proximity to the filter paper disc. All extracts, depending on their concentrations, showed different resistances to bacteria; however, their resistance to fungi differed. The assay showed that a 100.0 g·L-1 ethanol extract concentration of P. massoniana needles had a 25.6 mm diameter zone of inhibition against E. coli. For the three kinds of extracts, ethanol had the highest resistance and aqueous the lowest.The results shows that the extracts of P. massoniana needles have antimicrobial activity.
The insect, Mictiopsis curvipes, is a major pest of the host plant, Michelia yunnanensis. To control this pest, the insect's biological characteristics were studied through field observations from March of 2004 to August of 2007 in the campus of Southwest Forestry College and laboratory rearing. There were two, overlapping generations for M. curvipes each year with the adults overwintering in the litter layers on the ground. Two damage peaks, from mid July to mid September, were observed each year. The most serious damage period appeared when adults and nymphs emerged together. An effective method to control the pest was topping and pruning the host in mid May and early August.
There are three generations per year of the Opogona sacchari at Cixi City in Zhejiang Province. Twenty-five hosts belonging to 14 families were damaged by the moth. The larvae spent the winter in the host. The adult moths appeared from the late April to the early June, from the early July to the mid-August, from the early September to the late November. The periods for larva damage were from the early May to the early August, from the early July to the mid-October, from mid-September to late November. The emergence and activity of the adults happened in the night, and the nutrition must be supplied for the adults. The larva had 7 instars and the larvae could be fed by the fresh potato as artificial diet in the laboratory. The behavior of mutually massacres of the larvae was observed. It was an effective way to control the larvae that using 10 percent of imidacloprid diluted 700 times or 1.8 percent of avermectins diluted 1 500 times for spraying plants. When taking 1.8 percent of avermectins diluted 1 000 times to soaking injured Dracaena fragrans,death rate of Opogona sacchari was 97.1% after three days.
The relationship between Chinese and Japanese bamboo cultures, the status quo and phenomena of Japanese bamboo culture were studied and analyzed to reveal its connotations from the origin of the word “bamboo”. In the process of its formation and development, the Japanese bamboo culture absorbed the contents of the Chinese bamboo culture, and formed its uniqueness. Different from the Chinese bamboo culture, the Japanese bamboo culture was involved in more cultural aspects. It embodied not only Yamato living habits, psychological quality and aesthetic sentiment but also their inner world and spiritual pursuits. Bamboo played important roles in both daily life and spiritual life.
Because of advances in science and technology as well as the need for ecological and environmental development, research on root reinforcement of soil within the last 30 years has become a new multidisciplinary field. Thus, this article summarizes the progress of the preceding 3 decades and future considerations for research direction concerning root reinforcement in soils. Early studies on soil bioengineering stabilization mainly concentrated on root anti-tensile strength, its anchoring force, and the root-soil composite for increasing shear strength. However, future study should focus on: 1) quantitative analysis of cellulose and hemicellulose in the root system, 2) discussion on elasticity of different plant root systems, 3) differences in stretch resistance and stress-strain relationships, 4) the theory behind balancing water and soil conservation of plant species, and 5) the efficiency of root reinforcement in soils from the aspect of different mechanical characteristics. For slope stability, areas of study should include: 1) stress field, 2) stability of the slope to be afforested, and 3) for the slope to be planted, selection of the best tree species and planting density for optimum production.
The effects of climate, soil and topography factors on growth and fruit characters of Torreya grandis ‘Merrillii’ were reviewed to find out its favorable environment conditions and the existing problems in the previous research. Given the existing research on the favorable environment conditions of Torreya grandis ‘Merrillii’, it was found out that longtime quantitative observation research on environmental factors and macro analysis research based on global position system(GPS), remote sensing(RS) and geographic information system(GIS) were the topics needing further research.
The building of the government-oriented and farmer-participatory agricultural technology extension system is an important basis for the development of modern agriculture and building of the new socialist countryside. Based on the review of the status quo of the agricultural technology extension in Lin'an City, the paper analyzed the existing extension problems and put forward the corresponding solutions. The solutions are as follows:(1) strengthen the agricultural technology system construction, improve the service mechanism;(2) rely on the cooperative organizations to improve agricultural technology service level and broaden the service scopes;(3) organize and implement the extension programs to accelerate the application of technological achievements;(4) strengthen the education of professional knowledge, improve the quality of agricultural technology workers;(5) improve rewards and stabilize the team of agricultural technology extension;(6) intensify training to improve the farmers' level of science and technology and culture.
In order to optimize the distribution pattern of park green lands in Zhuji City, and also give some theoretical ideal for the distribution pattern of park green lands for other citys, this paper investigates park green lands in Zhuji by means of field data collection and analysis, analyzes and assesses its status quo distribution from the perspectives of classifying criteria, landscape ecology and landscape reachability, pointing out the problems of the lack of network architecture for overall distribution, the lack of distributional rationality for small green lands, and the failure to include all types of green lands. Finally, with a view to the features of Zhuji City, 6 pieces of advice for improvement are offered in terms of a balance in the distribution of various types of green lands, construction of big green lands, inclusion of all types of green lands, an overall network architecture of the distribution of green lands, emphasis on the balance on and the reachability of the distribution of green lands, and enhancement of social cultural values and local features.
Bambusa oldhami f. striata is a forma of Bambusa oldhami, having good ornamental value. This aim is to establish a tissue culture system for its commercial propagation. The new tender lateral bud were taken as the explants, Murashige and Skoog(MS) medium +30 g·L-1 sugar + 2.5 g·L-1Gelrite was the basic medium, and 6-Benzylaminopurine(BA) (0, 0.30, 1.00, 3.00, 10.00 mg·L-1) and thidiazuron(TDZ) (0, 0.01, 0.10, 1.00 mg·L-1) were added respectively to determine suitable concentration for tissue culture. The results showed that the shoot proliferation rate gradually increased with the concentration increasing of BA or TDZ, the effect of TDZ was better than BA, but the height growth of shoot was suppressed. 3.00 mg·L-1 BA+0.10 mg·L-1 TDZ was the best combination for shoot proliferation and shoot height growth. Declining or removing the cytokine could promote rooting.
Using available materials from local waste, such as peat soil, pearlite, wood chips, and rice husks, a suitable media for growing container seedlings of Ficus concinna var. subsessilis was selected. The experimental design was the Scheffe trial way for single-shaped barycenter mixture, and it was used to evaluate diameter at the root collar, underground biomass, and total biomass. The comprehensive multi-objective decision-making method was used for the analysis. Results showed that the most desirable growing medium was a mixture of 46% peat soil, 27% pearlite, and 27% wood chip husks.