首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The cotton whitefly, Bemisia tabaci (Genn.) (Hom., Aleyrodidae) is increasingly a very important pest on many vegetables, field crops and ornamental plants. Therefore, controlling of this pest is still needed especially under glasshouse conditions. The specialist whiteflies’ predator, Serangium parcesetosum Sicard (Col., Coccinellidae) appears to have a great potential for the cotton whitefly control. In this study, the dynamic changes in B. tabaci populations in glasshouse cabins in response to S. parcesetosum were monitored. B. tabaci were introduced to cotton plants in three cabins in average of 50 adults per plant. One and two weeks later, adult females and males of S. parcesetosum were introduced at a rate of one female and one male per plant in the first and second cabins, respectively. The third cabin was considered as a control. The results showed that the mean number of whiteflies in the control cabin was found significantly higher than that of either when S. parcesetosum was introduced 1 or 2 weeks after the infestation with the whitefly. Also, the mean number of B. tabaci was significantly higher when the predator was introduced 2 weeks rather than 1 week after B. tabaci infestation. The maximum mean weekly number of whiteflies/plant was 192.3 in the second week, whereas it was 294.6 in the third week and 1136.4 in the fifth week, in first, second and control cabins, respectively. In the last experimental week, the mean weekly numbers were 74.7, 122.9 and 684.7 whiteflies/plant in the three cabins, respectively. S. parcesetosum has been successfully fed, reproduced and established its population on B. tabaci on cotton plants. The mean weekly number of the predatory individuals increased gradually with the progress of the experimental time. The results demonstrated that the maximum reduction percentage in B. tabaci population was 90.7 and 86.5% in the fifth week after B. tabaci infestation, when the predator was introduced 1 and 2 weeks after the infestation with the whiteflies, respectively. Nevertheless, it is speculated that an earlier release of S. parcesetosum would be more effective in the biological control of B. tabaci.  相似文献   

2.
The development, longevity, fecundity and life-table parameters of the endoparasitoid Anagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae), 15 d.o. (3rd-instar nymphs) and 21 d.o. (young adult females) of the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) at 28 ± 1°C, 65 ± 10%RH and 16:8h L:D under laboratory conditions. The developmental time of female parasitoids within the host was 17.7 ± 0.39 days in 15 d.o. and 16.65 ± 0.25 days in 21 d.o. hosts; for males, development time was 16.85 ± 0.29 and 15.25 ± 0.09 days, respectively. The average number of offspring per female was 22.35 ± 1.68 in 15 d.o. and 34.8 ± 2.56 in 21 d.o. vine mealybugs. The longevity of female parasitoids was 14.8 ± 0.98 days in 15 d.o. and 15.65 ± 0.92 days in 21 d.o. mealybugs, respectively; for males, longevity was determined as 7.3 ± 0.43 and 6.7 ± 0.54 days, respectively. The mean time of pupation was 7.85 ± 0.003 days in 15 d.o. mealybugs and 8.65 ± 0.003 days in 21 d.o. mealybugs. The aggregate encapsulation rate in the parasitized 15 d.o. mealybugs was 49.73 and 60.36% in 21 d.o. mealybugs. Furthermore, effective encapsulation was 24.82% in 15 d.o. mealybugs and 37.50% in 21 d.o. mealybugs. Population growth rate (r m) for A. pseudococci was 0.0999 female/female/days in 15 d.o. mealybugs and 0.1269 female/female/days in 21 d.o. mealybugs. The mean population generation time was 23.49 days for parasitoids reared in 15-days-old and 22.39 days when reared in 21 d.o. mealybugs.  相似文献   

3.
The development of Diglyphus isaea (Walker), a parasitoid of leafminers, was studied under laboratory conditions at seven constant temperatures (10, 15, 20, 25, 30, 35, and 40°C) on Liriomyza sativae Blanchard reared on cucumber (Cucumis sativus L.). The total development period (oviposition to adult emergence) decreased with increasing temperature between 15 and 35°C. In 10 and 40°C no development rate was found in D. isaea, so that it may be claimed that these temperatures fall outside the temperature range for development. Linear regression was used to describe the relationship between development rate and temperature. For egg to adult development, males of D. isaea required 153.8 degree-days (DD) above the theoretical threshold of 9.2°C and females required 161.3 DD above 9.4°C. Data were fitted to four nonlinear temperature-dependent models. Evaluation of the models took place based on the following criteria: fit to data, number and biological value of the fitted coefficient, and accuracy on the estimation of the thresholds. It could be concluded that the Briere-1 and Briere-2 models are suitable for estimating the minimum, maximum and optimal temperature thresholds of D. isaea. Thermal requirements and temperature thresholds can be used to predict the occurrence, number of generations and population dynamics of D. isaea.  相似文献   

4.
 Parasitism by parasitoid wasps on the larvae of Epinotia granitalis (Butler), which is a wood-injuring pest in coniferous plantations, was observed for 6 years in two plantation forests of Chamaecyparis obtusa (Sieb. et Zucc.) Endl. and Cryptomeria japonica (L.f.) D. Don that were adjacent to each other and consisted of trees of almost the same size. E. granitalis larvae were collected from early April to mid-May, then reared in glass bottles, and finally examined to determine whether or not the larvae had been parasitized. Five species of parasitoids were recorded; two of them were classified in Ichneumonidae, Campoplex spp. A and B, and others in Braconidae, Iconella repleta Papp, Bassus cingulipes Nees von Esenbeck, and Bracon spp. In all 6 years, parasitism was first observed around 20 April. Species composition of parasitoids differed greatly among years and between forests. In 1 year in each forest the percentage parasitism increased significantly with the sampling date, indicating that not all parasitoids attack the same developmental stage of E. granitalis. The mean percentage parasitism per year was significantly higher in the forest of C. obtusa [11.5(%) ± 5.7(SD)] than in the forest of C. japonica (3.0 ± 4.1). These results suggest that the efficiency of parasitoid adults in finding hosts differed between the two forests. Received: September 20, 2001 / Accepted: August 5, 2002 Acknowledgments We are grateful to Dr. K. Maeto, Shikoku Research Center, Forestry and Forest Products Research Institute, and to Dr. K. Konishi, National Agricultural Research Center for Hokkaido Region, for identifying parasitoids, and to Dr. T. Miyaura, Forest Tree Breeding Center, and Dr. H. Kosaka, Forestry and Forest Products Research Institute, for their helpful advice throughout the study. Correspondence to:K. Kato  相似文献   

5.
The population dynamics of Bemisia tabaci and its parasitoids was studied on Gossypium hirsutum, Cucumis melo, Helianthus annus, Glycine max, Solanum melangena, Cucurbita pepo melopopo, Bauhinia pupurea, Morus alba, Albizzia lebbek, Lantana camara, Achyranthus aspera, and Convolvulus arvensis in cotton growing areas of Punjab, Pakistan during 2004 and 2005. Whitefly infested leaves having maximum number of second to third instar were collected and kept in glass petri dishes with lid on at 28 ± 2°C and 65 ± 3% RH. Mean population of whitefly adults that emerged per 200 cm2 leaf area per sampling period recorded was maximum on G. hirsutum (43.2), followed by C. melo (31.5), L. camara (23.0), H. annus (20.5), G. max (19.3), C. pepo melopopo (18.1), S. melangena (16.9), A. aspera (11.2), C. arvensis (9.2), B. pupurea (5.4), M. alba (5.3) and A. lebbek (5.0). Percentage parasitism was higher on G. hirsutum (44.3%), followed by C. melo (38.9%), A. aspera (38.3%), L. camara (38.1%), A. lebbek (35.3%), G. max (33.5%), C. arvensis (33.0%), M. alba (31.1%), B. pupurea (27.0%), S. melangena (24.8%), C. pepo melopopo (16.1%) and H. annus (15.2%). Overall the population of whitefly remained low during winter (November–February) and high during summer (May–August) whereas, the percentage parasitism was higher during June–September and lower during December–February. The study revealed that the availability of parasitoids could be enhanced by planting L. camara, B. pupurea, A. lebbek and M. alba in the cotton growing area.  相似文献   

6.
Serangium parcesetosum Sicard (Col., Coccinellidae) is considered one of the important predators of whiteflies. However, knowledge about its preferences for different prey stages, species and parasitized prey is still lacking in the literature. The present work investigated the preferences of S. parcesetosum for different stages of B. tabaci, different prey species and B. tabaci parasitized by Encarsia formosa Gahan (Hym., Aphelinidae) by prey consumption at different temperatures in the laboratory. Results showed that L2 and L4 predatory instars of S. parcesetosum preferred puparia to nymphs and eggs of Bemisia tabaci (Genn.) (Hom., Aleyrodidae). The mean daily prey consumption was 5.1–9.0, 4.5–6.2 and 3.6–4.3 by L2 and 6.4–9.7, 5.5–8.5 and 2.5–7.5 by L4 for puparia, nymphs and eggs, respectively. Adult females, however, indicated a significantly greater preference for both puparia and nymphs, consuming a daily mean of 6.4–7.5 puparia and 5.1–6.7 nymphs, but only 3.0–4.7 eggs. At 18 and 30 °C, all S. parcesetosum stages tested significantly preferred B. tabaci and Trialeurodes vaporariorum Westwood (Hom., Aleyrodidae) over the other three prey species offered. At both temperatures, all predatory stages preferred B. tabaci to T. vaporariorum, the L2 instar at 18 °C, showing significantly more preference for B. tabaci than T. vaporariorum. In contrast, very few individuals were consumed from Aphis gossypii Glover (Hom., Aphididae), Frankliniella occidentalis (Pergande) (Thys., Thripidae) and Tetranychus urticae Koch (Acari, Tetranychidae). At 18 °C, a daily mean of 7.5–8.0, 6.6–9.0 and 6.7–8.1 B. tabaci as well as 5.3–6.4, 5.4–7.8 and 5.6–6.3 T. vaporariorum was consumed by L2, L4 and adult females, respectively, while at 30 °C, L2, L4 and adult females consumed a mean of 9.3, 8.8–9.7 and 8.3–9.7 B. tabaci/day as well as 8.3–9.0, 7.8–9.1 and 5.5–8.4 T. vaporariorum/day, respectively. S. parcesetosum L2 and L4 instars as well as adult females and males at both studied temperatures showed a significant tendency to avoid B. tabaci puparia after 5 days of parasitism by E. formosa and preferred to feed on unparasitized whiteflies. At 18 °C, the mean daily consumption was 8.7 and 0.2 (L2), 11.1 and 0.6 (L4), 12.1 and 1.0 () as well as 10.5 and 0.2 (), while at 30 °C the means were 15.9 and 0.5 (L2), 19.8 and 1.0 (L4), 18.9 and 1.2 () as well as 17.4 and 0.6 () from unparasitized and parasitized B. tabaci puparia, respectively.This paper is gratefully dedicated to Prof. Dr. W Schwenke on his 83rd birthday, 22 March 2004  相似文献   

7.
Laboratory experiments investigated the effect of host instar, light and food on the number of mature eggs in ovaries (egg load) of the synovigenic parasitoid Venturia canescens (Grav.) (Hymenoptera: Ichneumonidae). The wasps that developed from third or fifth instar larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were exposed to food (honey) or had no food, had access to water or not, and were reared at the photoperiod 16:8 h light:dark or in continuous darkness at 25 ± 1°C, and 60–70% relative humidity. After death, the parasitoids were dissected to remove the reproductive systems, and mature eggs in ovaries were counted. A three-way ANOVA for egg number with host instar, food and light as factors revealed that egg load varied significantly. In addition, some interactions among the three factors were also found to be significant. The maximum average number (215.80 ± 8.51) of mature eggs was found when the parasitoids developed from third instar larvae, were exposed to continuous darkness and fed with honey. In conclusion, host instar, food supplement and photoperiod could have potential for improving biological control efficacy in stores. However, further studies determining the effect of these factors on egg laying behavior and fecundity should be done.  相似文献   

8.
The cutting seedlings ofLiriodendron chinense xtulipifera were treated with the different concentrations of auxin (treatment1: IBA of 50 g·kg−1+NAA of 300 g·kg−1; treatment2; IBA of 100 g·kg−1+NAA of 300 g·kg−1). The biomass nutrient element contents for different organs (root, stem, leaf) of cutting seedling ofLiriodendron chinense xtulipifera were measured by the dry method, Kjeldahl method and Atomic Absorption Spectroscopy method. The result showed that the biomass of root, stem, and leaf of the cutting seedling treated with auxin was all remarkably increased. The contents of element C in root, stem and leaf had no significant difference between the control and auxin treatments, while the contents of N, P, K and Ca in stem were much lower than that in leaf and root. Variance analysis showed that for the same organ with different concentration treatment of auxin, the four nutrient elements (N, P, K, and Ca) had no significant difference in contents, while there existed significant or very significant difference in contents of the four nutrient elements in different organs with the same concentration auxin treatment. The N, P, K and Ca contents were very low in cutting seedlings; as a result, additional fertilizer should be applied to the seedlings when they were planted in the field. Foundation item: This paper was supported by Jiangsu Province Science Foundation (BE96350). Biography: ZHANG Xiao-ping, (1972-), female, Ph. Doctor in Nanjing Forestry University. Nanjing 210037, P. R. China. Responsible editor: Zhu Hong  相似文献   

9.
We evaluated the survival and growth of Abies homolepis and Picea jezoensis var. hondoensis seedlings on Mt. Ohdaigahara, where the population of sika deer (Cervus nippon) is high and an experimental fence has been in place for 13 years. No significant differences were detected in the survival of small seedlings between fenced and unfenced plots. The growth of A. homolepis was significantly higher in the fenced plot, but growth of P. jezoensis var. hondoensis did not show significant differences between fenced and unfenced plots. Seedlings of height ≤5 cm in the forest floor vegetation of the unfenced plot were probably too small for deer to find and browse, so they survived.  相似文献   

10.
Rhyzopertha dominica (Fabricius) has developed extensive pesticide resistance in the last several decades. We have developed a supercritical fluid extraction method for Trigonella foenum-graecum L. (TFG) and studied the contact toxicities of the extracts to R. dominica. The extraction method was designed with orthogonal experiments to preserve and collect all the possible active components. Contact toxicity and efficiency of extraction were used as standard values to optimize extraction conditions, which were achieved at 55°C under 25 Mpa of pressure. The extraction efficiency for 200 g of dry sample reached 6.21% with 30 ml of 95% alcohol. Extracts loaded on filter paper showed dose and time dependent toxicities to adult R. dominica with a LC50 value of 65.02 μg/cm2 after 3 days post treatment. Our extensive in vivo studies indicated the extracts from Trigonella foenum-graecum seeds have high efficacy against pesticide resistant R. dominica. The active ingredient(s) from the extract shows promise as a novel pesticide candidate.  相似文献   

11.
The fresh pollen vitality,the effect of different storage conditions on the pollen vitality,and the difference of vitality among the species of seven species of Syringa were determined in Shenyang,China.The results indicated that the pollen vitality (81.5%) of Syringa villosa was the highest among the seven tested species,followed by S.microphylla and S.meyeri,and that of S.oblata var.affinis was the lowest.The low temperature was the best condition for storage of pollen of Syringa,and the most proper temperature for the storage was 0-2℃.The storability of S.microphylla was the best of all,and it could be stored over 60 days at the temperature of 0-2℃,next was S.villosa and S.meyeri.  相似文献   

12.
利用扫描电镜观察了忍冬（Lonicera jàponica Thunb）和华南忍冬（Lonicera confus）叶表皮形态特征,观察指标包括：气孔器、表皮毛、表皮细胞等.结果表明：气孔仅分布在下表皮,气孔器呈无规则型散生;上表皮细胞的垂周壁呈沟槽状下陷;下表皮密被表皮毛（包括腺状毛和非腺毛）,同时还分布有瘤状的草酸钙簇晶.为进一步证明这种瘤状结构是否为草酸钙簇晶,作者发现利用Fluo-3/AM（钙离子荧光指示剂）处理的活体叶片在激光共聚焦显微镜下能够发出强烈的荧光.此外,通过电子探针对瘤状物进行分析,发现其元素组成为C、O、Ca.上述叶表皮构造特征,有利于减少植物体水分散失,还有助于植物适应富钙的石灰土,从而适应我国西南岩溶区特殊的干旱、富钙的环境.电镜观察结果表明,在忍冬叶上表皮中脉处有呈线状分布的腺状表皮毛,而华南忍冬叶上表皮则无表皮毛分布,这一微形态特征可以作为二者种间特异性差别,从而为二者的合理区分提供一定的依据.  相似文献   

13.
General biology, seasonal flight numbers and ovipositional data were gathered to understand the phenology of the cherry bark tortrix, Enarmonia formosana Scopoli in Seattle, WA. Pheromone trapping during 2001 and 2002 showed a continuous flight period from May to September. During this time the greatest abundance of adults occurred during July and August. The combined seasonal egg data and larval developmental times indicate E. formosana is a univoltine species in the Pacific Northwest. Field releases of Trichogramma cacoeciae Marchal increased E. formosana egg parasitism on individual trees. During the two years, parasitism levels ranged from 72 to 74%.  相似文献   

14.
Cotton bollworm, Helicoverpa armigera Hubner selected for five generations with Bacillus thuringiensis insecticidal crystal protein Cry1Ac in the laboratory developed 12.98-fold resistance. Resistance and susceptible populations were mass crossed to study the dominance of resistance. The Cry1Ac—selected (BCR) population showed 5.8-fold resistance to Cry1Aa and 5.04-fold resistance to Cry1Ab. The degree of dominance (D) was 0.34 and 0.40 for the R × S and S × R hybrids, respectively, which indicates incomplete recessive character of Cry1Ac resistance in the population. The estimated realized heritability (h 2) and response quotient (Q) of resistance for Cry1Ac were 0.52 and 0.15, respectively. This indicated the lower phenotypic variation in the selected population. The resistance risk assessment based on h 2 indicated that the resistance would increased tenfold after <9 generations for Cry1Ac in the resistant population. The results show the ability of H. armigera to develop resistance against Cry1Ac and cross-resistance to Cry1Aa and Cry1Ab.  相似文献   

15.
The colonization preference and population trends of larval fig psylla Homotoma ficus L. were studied in Bursa, northwestern Turkey, from March 2000 to July 2001. Homotoma ficus overwintered at the egg stage on terminal buds and lenticels of shoots. Larval emergence occurred on 30th and 11th March in 2000 and 2001, respectively. Degree-day (DD) accumulations since 1st January indicate that the emergence of first larvae averaged 47 DD based on the larval developmental threshold of 10.9°C. Although the population trends of Homotoma ficus larvae were affected by temperature and rainfall, there was only significant relationship between larval abundance and temperature. The first instar larvae significantly preferred the bottom and the inside stipule of leaves. The second instar larvae distributed not only on expanding green tissues but also on both the upper and lower surface of leaves corresponding to the fig bud development period. Third to fifth instars colonized significantly greater on the bottom of leaves compared with the stipule and upper surface. In addition, significant linear relationship was found between fig phenology and cumulative larval counts. The importance of the colonization preference of larval instars and the use of fig phenology as well as DD for timing of insecticide treatments are discussed.  相似文献   

16.
Bursaphelenchus mucronatus Mamiya et Enda has been recovered for the first time from adults of the cerambycid beetle, Monochamus urussovi (Fischer), in Hokkaido, Japan. The nematode was also recovered from the inner bark of Picea jezoensis (Siebold et Zuccarini) Carrière and Abies sachalinensis (Fr Schmidt) Masters infested with M. urussovi larvae. PCR–RFLP analysis indicated that B. mucronatus in Hokkaido is the European type.  相似文献   

17.
The leaf essential oils (six samples) from three clones of Eucalyptus camaldulensis Dehnh. were characterized by gas chromatography-mass spectrometry. Radical scavenging and antioxidant properties were investigated by the 1,1-diphenyl-2-picylhydrazyl (DPPH) assay and the β-carotene bleaching test. It was found that the whole essential oil and its fractions had significant antioxidant effects when they were tested by each method. In the DPPH assay, the E. camaldulensis leaf oils showed IC50 inhibitory concentrations in the range of 1.75–12.62 mg/ml. In the β-carotene bleaching test, the IC50 valued were in the range of 14.30–118.55 μg/ml. Part of this report was presented at the 18th meeting of the Chugoku-Shikoku Branch of the Japan Wood Research Society, November 2006  相似文献   

18.
Embryo of lilacs (Syringa L) culture in vitro and the rapid propagation were studied. The orthogonal experiments, including the selection of basal medium, embryo age and other factors such as sugar, benzyladenine (BA), naphthalene acetic acid (NAA) and glutamine (Gln), were carried out. The results indicated that the optimal medium for embryo culture was Monnier medium supplemented with NAA (0.001 mg.L^-1), BA (0.1 mg.L^-1), sugar (50 g.L^-1), and Gin (400 mg.L^-1), with a germination rate of 91.7% at least; the optimal embryo age was 50 d; and Gln had significant effects on the germination rate of embryo.Moreover, the optimal medium for subculture was MS BA (2 mg.L^-1) NAA (0.001 mg.L^-1) Gln (0.5 mg.L^-1), with the propagation coefficient of 3.6 at least.  相似文献   

19.
In 2000, one-year-old seedlings of pyrenean oak (Quercus pyrenaica Willd.) and sessile oak (Quercus petraea [Matt.] Liebl) were planted in a thinned and an unthinned plot in a pinewood (Pinus sylvestris), and in a nearby clearing. In summer 2002 and 2003, water relations and gas exchange parameters were measured to address the impact of drought on the seedlings. Chlorophyll a fluorescence was also measured to explore leaf photochemistry and a possible non-stomatal limitation to photosynthesis (A). Reduction in stomatal conductance (g) in response to the decrease of predawn water potential (Ψpd) resulted the main cause affecting net carbon uptake. Water potential at midday (Ψmd) was similar in both species but Quercus petraea was more sensitive to soil water deployment occurred along summer, showing slightly lower Ψpd because worse recover of water potential during night. Rate of photosynthesis was higher in Q.␣pyrenaica probably in relation to its greater leaf mass per area (LMA) and nitrogen content per leaf area (Na). Mortality was highest in the clearing and lowest in the thinned pinewood. Throughout the summer, soil moisture was higher in the thinned area, possibly because of the reduction in tree transpiring surface and interception of rainfall. Accordingly, Ψpd of both species was higher in the thinned site.  相似文献   

20.
To clarify the biosynthetic pathway for syringyl lignans, especially syringyl tetrahydronaphthalene lignans and formation of the C2–C7′ linkage, production of (+)-lyoniresinol (LYR) and its predicted intermediates [syringaresinol (SYR), 5,5′-dimethoxylariciresinol (DMLR), and 5,5′-dimethoxysecoisolariciresinol (DMSLR)] in Lyonia ovalifolia var. elliptica was investigated by means of feeding experiments with radiolabeled precursors. Following individual administration of l-[U-14C]phenylalanine (Phe), [8-14C]sinapyl alcohol (SA), and [8,8′-14C]SYR to excised young shoots of L. ovalifolia and their subsequent metabolism, free [14C]lignans and [14C]lignan glycosides were extracted with methanol from stems and leaves and were divided into ethyl acetate-soluble fractions (lignans) and aqueous fractions (lignan glycosides), respectively. Using a combination of xylanase, cellulase, and β-glucosidase, the glycosides were hydrolyzed to liberate [14C]lignans as aglycones. l-[U-14C]Phe was incorporated into (+)-[14C]SYR [stem 0.38%, 8% enantiomeric excess (e.e.)], (−)-[14C]SYR (leaves 2.75%, 72% e.e.), (+)-[14C]DMLR (stem 0.07%, 18% e.e. and leaves 0.009%, 58% e.e.), (−)-[14C]DMSLR (stem 0.03%, 46% e.e. and leaves 0.05%, 20% e.e.), (+)-[14C]LYR (leaves 0.013%, 22% e.e.) and glycosides of (+)-[14C]LYR (stem 0.036%, 50% e.e.) in 24h. Based on the percent incorporation and enantiomeric composition of the lignans, the biosynthetic pathway of (8R,8′R)-(+)-LYR was proposed as follows: a nonselective dehydrogenative dimerization of sinapyl alcohol yields (±)-SYR, which is reduced with low specificity to give (8R,8′R)-(+)-DMLR. This is cyclized to directly give (+)-LYR as well as reduced again to (8R,8′R)-(−)-DMSLR. Although further transformation of (−)-DMSLR also leads to the formation of (+)-LYR, cyclization could be a main pathway for (+)-LYR biosynthesis. This report was presented at the IAWPS 2005 International Symposium on Wood Science and Technology, Yokohama, November 2005  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号