柞蚕核多角体病毒基因工程载体的研究——Ⅱ.柞蚕核多角体病毒多角体蛋白基因的克隆、定位及部份DNA的序列分析     

庄楚雄  张秋福  钟文彪  黄自然 《广东蚕业》1990,(1)

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柞蚕蛹感温发育阶段性激素变化的研究   总被引：5，自引：0，他引：5  

鞠贵春  李栋材 《吉林农业大学学报》1996,18(1):30-33

本研究采用放射免疫法（ＲＩＡ）检测了柞蚕蛹感温阶段睾酮和雌二醇的含量变化。经统计分析，血淋巴睾酮与积温呈曲线回归关系，雌二醇含量在发育过程中无显著变化。  相似文献   

柞蚕抗菌肽D基因在酵母中表达的研究   总被引：8，自引：2，他引：6  

叶玉坤  毛秋霞 《蚕业科学》1994,20(2):95-99

柞蚕抗菌肽具有广谱杀菌功能，人工合成抗菌肽Ｄ基因（１２２ｂｐ）与含α－因子及前导肽序列的穿梭质粒ｐＣＬＷＡ２重组，克隆于酵母ＡＢ１０３。在缺亮氨酸的ＹＥ培养基中筛选Ｌｅｕ＋阳性的转化子。转化子菌株培养扩增后提取重组质粒与抗菌肽基因片段探针作点杂交为阳性，电泳后插入含抗菌肽Ｄ基因１２８ｂｐ的区带。在转基因酵母的发酵液中分离上清液，浓缩，对抗菌肽敏感的指示菌Ｅ．ｃｏｌｉＫ１２Ｄ３１有明显抑菌效应。证实人工合成柞蚕抗菌肽Ｄ基因在酵母中表达。  相似文献   

不同水肥对猩红栎轻基质容器苗生长的影响     

胡丁猛  臧真荣  王开芳  王翠香  任飞  吴德军  尹国良 《山东农业科学》2012,44(12):54-56

对1年生猩红栎轻基质容器苗进行不同的水肥处理试验,结果表明,A1B2组合(浇水1天1次,施肥0.2 g/株)处理时,猩红栎轻基质容器苗质量最好;水分为猩红栎容器苗生长的重要因子。  相似文献   

Autecology of sessile oak (Quercus petraea) in the north-west Iberian Peninsula     

《Scandinavian Journal of Forest Research》2012,27(6):458-469

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Changes in soil properties of Abies holophylla and Quercus-dominated stands 4 years after trenching     

《Scandinavian Journal of Forest Research》2012,27(6):597-604

Abstract

Few studies tried to isolate the influence of plant roots on the soil characteristics including soil carbon (C) and nitrogen (N) storage. We evaluated the impact of root trenching on soil characteristics of coniferous (Abies holophylla) and deciduous (Quercus spp.) stands 4 years after trenching. Trenching treatment significantly increased the soil water content and nitrate concentration in both stand types. Soil pH, cation exchange capacity, soil C and N pools and isotopic compositions of C and N were significantly different between two stands, but trenching was not found to have significant impact on these soil properties. Our results indicated that root trenching in coniferous and broad-leaved deciduous forests of temperate region could significantly alter soil moisture regime and inorganic N levels, but not C and N stabilization in soils.  相似文献   

金苍林场蒙古栎天然中龄林竞争关系研究   总被引：6，自引：1，他引：5       下载免费PDF全文

沈琛琛  雷相东  王福有  马武  沈剑波 《林业科学研究》2012,25(3):339-345

以吉林省汪清林业局金仓林场2块面积为0.25 hm2的蒙古栎天然中龄林固定样地为对象,采用8个竞争指标,研究蒙古栎天然林种内、种间竞争状态。研究结果表明,该林分竞争激烈,蒙古栎与其他各树种存在种间竞争,但其主要竞争压力来自种内,种外竞争压力主要来自黑桦与白桦。其它树种的竞争主要为种间竞争。蒙古栎竞争能力处于中等,白桦与黑桦最强。各竞争指标结果存在差异性,但均能反映蒙古栎天然林竞争状态。蒙古栎竞争强度与胸径存在幂函数关系,竞争强度随个体大小的增大而减小。  相似文献   

A Screening Trial of 28 Species Conducted on Non-Saline and Saline Soils in Dry Tropical Northeast Australia     

《Journal of Sustainable Forestry》2013,32(3-4):1-13

Abstract

A trial to examine the suitabilities of 28 tree species for both non-saline and saline soils was carried out in a dry tropical area of northern Australia. The trial consisted of two experiments, Experiment 1 on a non-saline site and Experiment 2 on a saline site. In each experiment, trees of all the species were grown in a randomised complete block design with 6 blocks (replicates) and were measured for survival; height and diameter at breast height (DBH) at age 24 months. These parameters were found to differ significantly between species in both experiments. Of all species tested, Azadi-rachta indica, Eucalyptus camaldulensis, E. citriodora, E. maculata, E. pellita, E. raveretiana, Khaya senegalensisand Paulowniafortue-niihad high survival and fast growth in height and DBH on the non-saline site while E. camaldulensis, E. drepanophylla, E. moluc-cartaand E. raveretianaperformed better on the saline site. Salinity greatly affected survival for some species and reduced tree growth in both height and DBH for most species tested. E. camaldulensisis suggested to be one of themost important species for land rehabilitationin theregion.  相似文献   

Ozone,Acid Deposition,and Mycorrhization Effects on Loblolly Pine and White Oak     

《Journal of Sustainable Forestry》2013,32(2-3):31-58

Abstract

Above- and below-ground responses of juvenile loblolly pine (Pinus taedaL.) and white oak (Quercus albaL.) to tropospheric ozone (0.0, 0.06, and 0.12 μL L^-1 O₃), acid precipitation (pH 4.8, 4.2, and 3.6), and induced ectomycorrhizal colonization (Pisolithus tinctorius [Pers.] Coker & Couch vs. natural mycobiont), alone and in combination, were examined. After 30 weeks, the filtered air treatment (ozone 0.0) reduced foliar injury but also produced smaller stem diameters, lower total foliage and total shoot dry weights, decreased needle density, and shorter root systems in inoculated pine, growth responses not found in uninoculated pine. Height growth of inoculated oak was increased by the filtered air treatment while leaf density was reduced by 0.12 μL L^-1 O₃, results also not found in uninoculated oak. Ectomy-corrhizal colonization percentages in pine decreased with increasing O₃ concentration regardless of mycorrhizal treatment, and the filtered air treatment produced the highest infection percentages in inoculated oak as well. Rains of pH 4.2 stimulated height growth in inoculated pine while diameter decreased in inoculated oak but increased in uninoculat-ed oak with declining pH. Also, pH 4.2 rainfall increased root weight in inoculated oak while that of pH 4.8 reduced foliar injury but also shoot weight in oak regardless of mycorrhizal treatment. Generally, the my-corrhization response to increasing rainfall acidity was reduced colonization. Independent of the other treatments, inoculation produced a substantial increase in above- and below-ground growth of both pine and oak, and also increased foliage density but reduced specific root length in each species. Overall, these results indicate that the growth responses to O₃ and acid deposition of loblolly pine and white oak are strongly influenced by mycorrhization, but that the magnitude of these responses is exceeded by those to mycorrhization alone. However, the propensity revealed here for both O₃ and acid precipitation to suppress mycorrhizal colonization in these two species may indicate the potential for a gradual reduction in long-term forest productivity in the southeastern United States.  相似文献   

Brenneria spp. and Rahnella victoriana associated with acute oak decline symptoms on oak and hornbeam in Iran     

Yousef Moradi‐Amirabad  Heshmat Rahimian  Valiollah Babaeizad  Sandra Denman 《Forest Pathology》2019,49(4)

Decline diseases of forest trees are complex syndromes not attributable to single causal factors. In Iran, symptoms of decline disease have been observed in a number of native forest species including Quercus castaneifolia (chestnut‐leaved oak), Q. brantii (Persian oak) and Carpinus betulus (hornbeam). The symptoms are prevalent in the northern forests and the Zagros mountain forests. There are parallels between the disease in Iran and acute oak decline (AOD) reported in the UK, specifically the presence of weeping cankers, which have been attributed to a polybacterial complex wherein Brenneria goodwinii is considered a key necrogen. Based on the AOD symptomatology, and as a first step towards discovering potential causal agents of the stem weeping symptoms of affected trees in Iran, necrotic tissues were tested primarily for the presence of B. goodwinii. Symptomatic Q. castaneifolia and C. betulus from the Mazandaran Province and symptomatic Q. brantii from Kohgiluyeh and Boyerahmad Province were sampled. Isolation and culture on a selective medium yielded uniform bacterial colonies. Isolates were characterized using phenotypic and genotypic (DNA sequencing) tests. The isolates were phenotypically identical to members of Pectobacteriaceae and Yersiniaceae, specifically Brenneria and Rahnella spp. The nucleotide sequences of the 16S rRNA and housekeeping genes gyrB, infB and atpD (MLSA) amplified via PCR demonstrated that the isolates from the trees in Iran were indeed B. goodwinii, B. roseae subsp. roseae, Rahnella victoriana and an unknown species of Brenneria. Most bacteria isolated from non‐symptomatic trees were Gram‐positive, and Pseudomonas spp. were dominant, but bacterial species isolated from the diseased trees were not detected in healthy trees. Hypersensitivity response tests were positive, but inoculation on saplings was more variable with internal necrosis developing only once in the test period. Therefore, further testing is required. This is the first report of the incidence of B. goodwinii, B. roseae subsp. roseae, R. victoriana and Brenneria sp. associated with acute oak decline‐like symptoms on Q. castaneifolia, Q. brantii and C. betulus across the western forests of Iran and in the world.  相似文献