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在青篱竹属Arundinaria 系统分类中由于对该属的形态分类标准取舍不一,至今仍存在着严重的意见分歧。本文采用PCR 扩增产物直接测序的方法分析青篱竹属Arundinaria 及近缘属(如苦竹属Pleioblastus、矢竹属Pseudosasa、少穗竹属Oligostachyum、巴山木竹属Bashania、肿节竹属Clavinodum 等)有关争议属的代表种或模式种(毛竹为外类群)等18 种竹种的核糖体DNA ITS 区段序列和叶绿体DNA trnL-F 序列。分别对ITS 序列、trnL-F 序列和ITS 与trnL-F 的组合序列进行系统发育分析。结果表明,和trnL-F 区段序列相比,核糖体DNA ITS 区段序列有较高的系统发育信息位点。通过最简约分析产生的ITS 树、trnL-F 树和ITS 与trnL-F 的组合序列树表明,所得树形基本相似。供试竹种(斑苦竹A. oleosa、仙居苦竹A. hsienchuensis、茶秆竹A. amabilis、长叶苦竹A. chino、苦竹A. amara、宜兴苦竹A. yixingensis、菲白竹A. fortunei、翠竹A. pygmaea、大明竹A. gramineus、巴山木竹A. fargesii、冷箭竹A. faberi、凤竹A. hupehense、鼓节矢竹P. japonica cv. Tsutsumiana、矢竹P. japonica、短穗竹B. densiflorum、肿节竹A. oedogonata、少穗竹A. sulcata)形成一个单系类群,且分为2 个不同的分支。图3 表2 参11。 相似文献
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高效、稳定的基因组DNA提取是进行分子标记辅助育种研究的关键技术环节之一。以刺槐叶片为材料,将传统的CTAB法进行优化改良,结合组织研磨棒液氮研磨建立刺槐基因组DNA的提取方法。将提取获得的基因组DNA进行SSR分子标记技术研究,获得的条带清晰、稳定.表明提取获得的基因组DNA能很好的满足SSR分子标记的需要。为刺槐遗... 相似文献
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4种不同广玉兰基因组DNA提取方法的比较 总被引:2,自引:1,他引:2
采用常规CTAB法、常规SDS法、改良CTAB法、改良SDS法4种方法对广玉兰(Magnolia grandiflora)叶片基因组DNA的提取进行比较,并进行ISSR—PCR检测,结果表明:改良的CTAB法提取的基因组DNA效果比常规CTAB法、常规和改良SDS法都好,提取DNA的浓度和纯度高,无蛋白质和RNA等杂质影响,并且可以很好的应用于ISSR分子标记分析,ISSR—PCR反应体系中模板DNA的最佳浓度是30ng/20μl. 相似文献
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简述了核酸杂交技术、聚合酶链式反应(PCR)扩增技术、分子指纹技术和克隆基因文库技术4种分子生物学技术,综述了4种技术在海洋、湖泊、河流和其它水生态系统中微生物多样性的研究进展,研究内容大致可分为三个方向:一是人类活动对水环境微生物多样性的影响;二是种群结构和污染之间的规律;三是菌株的筛选和利用,使人们可以在水环境保护、治理过程中变得更加高效、有的放矢。 相似文献
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以插入Taq DNA聚合酶基因的pET-24a表达质粒转化E.coli菌株,表达Taq DNA聚合酶,用反复冻融的方法裂解菌体.表达产物为可溶性蛋白,采用Duo-Flow系统(Bio-Rad)及S柱,Tris缓冲液pH为7.5.以0-1 mol/L盐梯度洗脱方式,收集洗脱峰.透析去盐可得到高纯度的产品.经PCR反应与商品Taq酶的一个活性单位相比较,重组的Taq酶活性有1个单位.用该方法可以从1 L培养液中分离得到5.51 mg产品. 相似文献
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以插入重组Taq DNA聚合酶基因的pET-24a表达质粒转化大肠杆菌菌株,转化菌铺平板的最佳量为50至100 μL,可获得转化菌的单菌落,单菌落扩大到200 mL培养量,表达Taq DNA聚合酶,经SDS-PAGE分析,表达带的相对分子质量约为82 ku,最佳表达条件为接种量1/500,工程菌培养到OD600值为1.0开始诱导,以2 mmol/L IPTG诱导8 h,Taq DNA聚合酶可获得较高的表达效率. 相似文献
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Biochemical and molecular markers have proven to be powerful tools for discerning biosystematic, biogeographic, and phylogenetic relationships. Biosystematic information can be important for guiding traditional breeding programs, gene transfer, interspecific hybridization, and gene conservation. A phylogenetic framework is usually necessary, but frequently ignored, for making valid statistical tests in studies of adaptive evolution. Several studies have indicated a strong correlation between biochemical races and traits important to growth and adaptation, suggesting that evolutionary legacy may affect genetic architecture of fitness traits — with consequences for seed transfer, breeding strategies, and tolerance of climate change. A number of methods for phylogenetic analysis exist, but differ in their assumptions. Use of an inappropriate method — such as a method that assumes constant rates of evolution when rates in fact vary — can lead to incorrect phylogenies. Because of their complexity, phylogenetic topologies are often difficult to determine unambiguously; estimates of statistical confidence should therefore accompany phylogenetic trees if they are to be regarded as providing new knowledge, or strong confirmation, of relationships. Molecular genetic markers are more expensive than biochemical markers such as allozymes and terpenes, but they provide increased accuracy and expanded scope of biosystematic inference, and facilitate statistical analyses of phylogenetic trees.Abbreviations BMGMs
biochemical and molecular genetic markers
- cpDNA
chloroplast DNA
- OTU
operational taxonomic unit
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rbcL
chloroplast gene encoding ribulose 1,5-bisphosphate carboxylase large subunit
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rbcS
nuclear gene encoding ribulose 1,5-bisphosphate carboxylase small subunit
- rDNA
ribosomal DNA
- RFLP
restriction fragment length polymorphism
- UPGMA
unweighted pair group method of clustering using averages
This is paper 2708 of the Forest Research Laboratory, Oregon State University. 相似文献
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The Luquillo Experimental Forest (LEF) located on the Caribbean island of Puerto Rico has a rich history of ecological research, including a variety of avian studies, and is one of the most active ecological research sites in the Neotropics. The LEF spans an elevational range from 100 to 1075 m over which five life zones and four forest types are found in a warm, humid subtropical climate. A total of 23 bird species breeds here and another 76 species, mostly migrants, are known to occur. The food web of the forest in the lower elevations is especially well studied, which allows an assessment of the role of birds in the food web. The LEF is noted for its high densities of Eleutherodactylus frogs and Anolis lizards, which may depress insect densities thereby contributing to the low species richness and densities of most insectivorous birds. The signature species of the forest is the endangered Puerto Rican Parrot (Amazona vittata) that has been the focus of intensive long-term research and recovery efforts, which have spawned research on associated species, including long-term studies on the Pearly-eyed Thrasher (Margarops fuscatus) and botfly (Philornis spp.) ectoparasitism. Given the frequency of hurricane disturbance to the LEF and studies providing baseline for comparisons, research has made major contributions to an understanding of the effects of hurricanes on forest ecosystems including bird populations and their resources. We summarize these and other studies from the LEF to characterize the avifauna and its environment while noting studies with management implications and identify opportunities for future ornithological studies. 相似文献
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为建立思茅松大配子体ISSR分子标记的反应体系,以思茅松种子样本作为供试材料,比较不同思茅松胚乳DNA提取方法的效果,通过紫外分光度计、DNA琼脂糖电泳和PCR扩增分别予以检测并比较。结果表明SDS法优于CTAB法。同时,通过单因子分析法对ISSR-PCR反应体系中的模板DNA用量,Taq DNA聚合酶用量,Mg2+浓度,dNTP浓度、引物浓度等主要影响因子进行优化,确立适用于思茅松的ISSR分子标记反应体系。对该体系进行稳定性检验,结果表明该反应体系适合思茅松ISSR-PCR扩增。 相似文献
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利用同源序列克隆技术,分离了三倍体黑杨中4类(MET、CMT、DRM、DNMT2)8个特异甲基转移酶片段,其中,5个片段与二倍体同源性达到100%,3个片段发生了剪切变化。通过实时定量PCR技术检测8个甲基转移酶在不同倍性、不同部位、不同生长时期间表达模式的差异,通过对5个不同部位基因表达的检测,表明不同倍性黑杨在相同的部位可能由不同种类的甲基转移酶参与主要的甲基化调控。通过分析植株从分化早期的茎尖到分化晚期的叶和茎整个生长过程中基因表达的情况,发现随着时间的推移,MET家族 (PnD1和PnD2) 基因可能是拮抗调节,CMT (PnD3和PnD4) 家族基因可能是协同调节;而隶属于DNMT2家族的PnD6基因在各部位的表达都比较弱,唯独三倍体茎尖有很高的表达。由于茎尖是生长旺盛的部位,PnD6有可能是影响三倍体速生的重要基因。这些结果可能暗示,DNA甲基转移酶基因可能参与了黑杨发育过程中叶片形态发生的过程。 相似文献
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The Fort Valley Experiment Station (now Fort Valley Experimental Forest) has contributed many long-term studies to forest research. This paper focuses on a “Methods of Cutting” study initiated in 1913 on the Coulter Ranch Unit of Fort Valley and how that long-term study yielded important ecological and management lessons. We quantified the historical and contemporary forest patterns at this ponderosa pine-Gambel oak site, which was harvested using three different harvesting systems in 1913 (seed tree, group selection, and light selection) and was partially excluded from livestock browsing in 1919. Using nine historically stem-mapped permanent plots for the following three stand structural scenarios: 1913 pre-harvest (modeled), post-harvest (actual), and 2003-2006 (actual) conditions, we examined the short- and long-term consequences of harvest and livestock grazing land-use and stand dynamics. We assessed changes in spatial pattern under each harvesting system and in each structural scenario, and lastly, we examined spatial and temporal tree recruitment patterns as observed in the contemporary (2003-2006) conditions. The seed tree harvests effectively converted the spatial patterns from aggregated to random and left few trees, while the group selection and light selection had varying effects, but consistently exaggerated the spatial patchiness of the stand. By 2003-2006, all plots were aggregated at all scales and were one large patch of predominately small trees. Sites that were harvested, but excluded from livestock browsing had 40% more trees in 2003-2006. Contemporary recruitment patterns were significantly aggregated under all harvesting systems, but were most strongly aggregated if the site received a group selection or light selection cut. For group and light selection, pine seedlings initially established in stump patches created by harvesting and then proceeded to fill-in the remaining area, with recruitment rarely found under the residual pine or oak trees. Long-term data sets, such as these established by the Fort Valley Experimental Forest in 1913, are essential for quantifying the impact of historical land-use practices on contemporary forest composition and structure. Ignoring land-use legacies may lead to the misinterpretation of stand dynamics and development, and therefore should be explicitly quantified and incorporated into future management and restoration activities. 相似文献
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Forest soil measurements were made at over 180 sites distributed throughout the H.J. Andrews Experimental Forest (HJA) in the Oregon Cascade Mountains. The influences of both elevation and aspect on soil variables were measured in the early (1998) and late summer (1994). Increased elevation significantly increased soil moisture, mean annual precipitation, soil organic matter, labile C and mineralizable N, microbial activities, extractable ammonium, and denitrification potentials. In contrast, bulk density, pH and soil temperature (1998 only) were significantly lower at the higher elevations. Relative to labile C, mineralizable N was preferentially sequestered at higher elevations. Aspect significantly affected annual mean temperature and precipitation, soil moisture and temperature, soil organic matter, mineralizable N, extractable ammonium, denitrification, and microbial activities. There were no significant higher statistical interactions between elevation and aspect on climatic or soil factors. Soil organic matter (SOM) accumulation at higher elevations is likely driven by a reduction in decomposition rates rather that an increase in primary productivity, however, SOM accumulation on north facing slopes is probably due to both a decrease in decomposition and an increase in primary production. Models of climate change effects on temperate forest soils based on elevational studies may not apply to aspect gradients since plant productivity may not respond to temperature–moisture gradients in the same way across all topographical features. 相似文献