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91.
Pollen morphology of the native Sicilian species of the genus Muscari, one of which is endemic to Sicily, belonging to the subgenera Muscari, Leopoldia and Pseudomuscari, was studied using a light microscope and a scanning electron microscope. Pollen grains are monads, heteropolar and monosulcate; the exine is semitectate reticulate and perforate. The sulcus extends from distal to proximal face and its length is not directly proportional to the size of the granules and varies from one species to another.  相似文献   
92.
Primary biodiversity data are often organised in federated databases in the framework of big international projects and initiatives. Other data are normally organised into isolated resources: ecological, morphological and morpho-anatomic databases, checklists, archives of digital identification tools, etc. These data, which do not refer specifically to one specimen or observation, but to a taxon, can be addressed to as “taxon-related data”. In the framework of the Italian Biodiversity Network, taxon-related data have been aggregated by using a federated approach, with the creation of a network of data providers, which required the development of a communication protocol, the species-related data (SRD) protocol and of a simple data format (the SRD format). The SRD federated database aggregates currently ca. 70,000 taxon pages for several groups of organisms: vascular plants, lichens, mosses, algae, freshwater fishes and butterflies. All these resources can be queried by using one simple interface in the web portal of the Italian Biodiversity Network (http://www.naturaitalia.it/nnb/).  相似文献   
93.
Although it is generally recognized that global biodiversity is declining, few studies have examined long‐term changes in multiple biodiversity dimensions simultaneously. In this study, we quantified and compared temporal changes in the abundance, taxonomic diversity, functional diversity, and phylogenetic diversity of bird assemblages, using roadside monitoring data of the North American Breeding Bird Survey from 1971 to 2010. We calculated 12 abundance and diversity metrics based on 5‐year average abundances of 519 species for each of 768 monitoring routes. We did this for all bird species together as well as for four subgroups based on breeding habitat affinity (grassland, woodland, wetland, and shrubland breeders). The majority of the biodiversity metrics increased or remained constant over the study period, whereas the overall abundance of birds showed a pronounced decrease, primarily driven by declines of the most abundant species. These results highlight how stable or even increasing metrics of taxonomic, functional, or phylogenetic diversity may occur in parallel with substantial losses of individuals. We further found that patterns of change differed among the species subgroups, with both abundance and diversity increasing for woodland birds and decreasing for grassland breeders. The contrasting changes between abundance and diversity and among the breeding habitat groups underscore the relevance of a multifaceted approach to measuring biodiversity change. Our findings further stress the importance of monitoring the overall abundance of individuals in addition to metrics of taxonomic, functional, or phylogenetic diversity, thus confirming the importance of population abundance as an essential biodiversity variable.  相似文献   
94.
The characters of mature leaf epidermis of 58 species and 3 varieties belonging to 19 sections, representing all the 4 subgenera: Protocamellia, Camellia, Thea and Metacamellia were investigated under light microscope. The main conclusions are as follows: 1) The shape of the epidermal cells is elliptical, polygonal or irregular and the anticlinal walls are arched, straight or sinuolate, sinuous to sinuate. 2) The stomatal apparatus, consisting of a stoma (a pore plus a pair of guard cells) and 3–4 subsidiary cells, restricted to the abaxial surface of the leaves, were assigned to anisocytic, anisotricytic, isotricytic or tetracytic type. 3) Special structures in leaf epidermis, such as stomatal clusters, aborted stomata, secretory cells, cuticular intrusions and their taxonomic implications were also elucidated.  相似文献   
95.
The concept of taxonomic sufficiency (identifying organisms only to a level of taxonomic resolution sufficient to satisfy the objectives of a study) has received little attention in ecological studies of terrestrial invertebrate assemblages. Here we critically evaluate three approaches to taxonomic sufficiency: the use of morphospecies, genera and functional groups. The objective was to compare estimates of richness (α diversity) and turnover (β diversity) of ant assemblages generated by these data with estimates produced using data for ant species. Ground-active ants were sampled using pitfall trapping within three habitat types: a eucalypt plantation, woodland regrowth patches and the surrounding grassland at a study site in the upper Hunter Valley, New South Wales. Comparisons of assemblage richness and turnover among taxonomic data sets and habitats and after different data transformations used univariate (simple correlation and ANOVA ) and multivariate (Mantel tests, ANOSIM and SSHMDS ) techniques. Our study found: (i) morphospecies and genus richness was highly correlated with species richness over the study area; (ii) ordination scatterplots using species, morphospecies and genus data revealed similar patterns of site separation for the three habitats; (iii) the results were very similar using untransformed, log transformed and binary data; (iv) functional group ordinations separated all three habitat types for untransformed abundance data; and (v) estimates of species turnover were highly correlated with estimates of morphospecies and genus turnover. These results are discussed in relation to future monitoring of ant community structure.  相似文献   
96.
中国的光肩星天牛类群   总被引:16,自引:0,他引:16  
吴蔚文  蒋书楠 《昆虫学报》1998,41(3):284-290
该文讨论我国光肩星天牛Anoplophoraglabrlpennis(Motschulsky)类群的外部形态和外生殖器的主要鉴别特征,寄主、地理分布、起源及其演化。光肩星天牛主要分布在山西吕梁山、太行山以东的广大平原地区,寄主广泛,主要有榆、复叶槭、杨、柳、五角枫等。黄斑星天牛主要分布在秦岭以北,山西吕粱山太行山以西的陕甘宁地区,向东已扩展到河南、河北;主要为害杨树,也为害柳、榆。四川星天牛主要分布于秦岭以南的西部地区,北限在陕西太白山到甘肃天水一带;主要为害柳。在秦岭以北到天水之间是黄斑星天牛和四川星天牛的重叠分布区,山西太行山两侧南北走向的狭长地带是光肩星天牛和黄肩星天牛重叠分布区,两个狭长地带交会处,大约在秦岭以北的陕西和(或)山西境内有三个种的重叠分布区域.在云、贵、川地区广泛分布着四川星天牛,至今还没有发现光肩星天牛、黄斑星天牛和蓝角星天牛,后者应该是一个值得怀疑的种。  相似文献   
97.
The emergence of multicellularity is strongly correlated with the expansion of tyrosine kinases, a conserved family of signaling enzymes that regulates pathways essential for cell-to-cell communication. Although tyrosine kinases have been classified from several model organisms, a molecular-level understanding of tyrosine kinase evolution across all holozoans is currently lacking. Using a hierarchical sequence constraint-based classification of diverse holozoan tyrosine kinases, we construct a new phylogenetic tree that identifies two ancient clades of cytoplasmic and receptor tyrosine kinases separated by the presence of an extended insert segment in the kinase domain connecting the D and E-helices. Present in nearly all receptor tyrosine kinases, this fast-evolving insertion imparts diverse functionalities, such as post-translational modification sites and regulatory interactions. Eph and EGFR receptor tyrosine kinases are two exceptions which lack this insert, each forming an independent lineage characterized by unique functional features. We also identify common constraints shared across multiple tyrosine kinase families which warrant the designation of three new subgroups: Src module (SrcM), insulin receptor kinase-like (IRKL), and fibroblast, platelet-derived, vascular, and growth factor receptors (FPVR). Subgroup-specific constraints reflect shared autoinhibitory interactions involved in kinase conformational regulation. Conservation analyses describe how diverse tyrosine kinase signaling functions arose through the addition of family-specific motifs upon subgroup-specific features and coevolving protein domains. We propose the oldest tyrosine kinases, IRKL, SrcM, and Csk, originated from unicellular premetazoans and were coopted for complex multicellular functions. The increased frequency of oncogenic variants in more recent tyrosine kinases suggests that lineage-specific functionalities are selectively altered in human cancers.  相似文献   
98.
北京地区手参内生真菌的区系组成分析   总被引:1,自引:0,他引:1  
手参Gymnadenia conopsea是一种地生兰科植物,也是中国传统中药材之一。研究以ITS1为目标序列,应用 Illumina MiSeq高通量测序技术对北京地区松山和百花山的手参内生真菌区系组成进行测定分析。结果表明,从手参的根中获得有效序列50 420条,209个可操作分类单元(OTUs),分属于3门9纲28目54科,包括盘菌纲Pezizomycetes(3个OTU)、伞菌纲Agaricomycetes(21个OTU)、锤舌菌纲Leotiomycetes(18个OTU)、粪壳菌纲Sordariomycetes(51个OTU)、接合菌纲Zygomycetes(18个OTU)、银耳纲Tremellomycetes(19个OTU)、散囊菌纲Eurotiomycetes(22个OTU)、酵母纲Saccharomycetes(8个OTU)、座囊菌纲Dothideomycetes(14个OTU)。其中,百花山手参根中内生真菌优势类群是鸡油菌目Cantharellales(38.62%)和柔膜菌目Helotiales(24.64%)真菌;松山手参的优势内生菌类群是盘菌目Pezizales(66.19%)和鸡油菌目Cantharellales(29.75%)真菌。这些结果利于系统了解手参根部内生真菌区系组成以及优势内生真菌类群,为今后开展相关内生真菌在手参人工繁育中的应用奠定了基础。  相似文献   
99.
DNA barcoding involves the use of one or more short, standardized DNA fragments for the rapid identification of species. A 648‐bp segment near the 5′ terminus of the mitochondrial cytochrome c oxidase subunit I (COI) gene has been adopted as the universal DNA barcode for members of the animal kingdom, but its utility in mushrooms is complicated by the frequent occurrence of large introns. As a consequence, ITS has been adopted as the standard DNA barcode marker for mushrooms despite several shortcomings. This study employed newly designed primers coupled with cDNA analysis to examine COI sequence diversity in six species of Pleurotus and compared these results with those for ITS. The ability of the COI gene to discriminate six species of Pleurotus, the commonly cultivated oyster mushroom, was examined by analysis of cDNA. The amplification success, sequence variation within and among species, and the ability to design effective primers was tested. We compared ITS sequences to their COI cDNA counterparts for all isolates. ITS discriminated between all six species, but some sequence results were uninterpretable, because of length variation among ITS copies. By comparison, a complete COI sequences were recovered from all but three individuals of Pleurotus giganteus where only the 5′ region was obtained. The COI sequences permitted the resolution of all species when partial data was excluded for P. giganteus. Our results suggest that COI can be a useful barcode marker for mushrooms when cDNA analysis is adopted, permitting identifications in cases where ITS cannot be recovered or where it offers higher resolution when fresh tissue is. The suitability of this approach remains to be confirmed for other mushrooms.  相似文献   
100.
为了解黄渤海甲壳类的分类多样性特征, 我们统计了2010-2015年中国水产科学研究院黄海水产研究所调查捕获的黄渤海甲壳类(软甲纲: 十足目与口足目)物种名录。结合历史文献, 进一步系统整理得到黄渤海甲壳类物种总名录。基于这2个名录, 应用分类阶元包含指数(the inclusion index at taxonomic level, TINCLi)、平均分类差异指数(average taxonomic distinctness index, Δ+)和分类差异变异指数(variation in taxonomic distinctness index, Λ+)研究了其分类多样性特征。结果显示: 2010-2015年调查名录中, 甲壳类共93种, 隶属于2目39科66属, 其中10种为新分布种; 对虾科、藻虾科、长臂虾科、梭子蟹科和弓蟹科的物种数最多, 合计占总物种数的38.71%; TINCLi分别为1.41种/属和2.38种/科; Δ+和Λ+分别为50.25和35.20。总名录中, 甲壳类共228种, 隶属于2目53科123属, 其中藻虾科、豆蟹科、对虾科、弓蟹科和鼓虾科的物种数最多, 合计占总物种数的30.70%; TINCLi分别为1.85种/属和4.30种/科, Δ+和Λ+分别为50.18和30.87。对虾科的相对丰富度指数(the relative richness index, Rr)最高(100), 其次是梭子蟹科(71.43)和长臂虾科(62.50), 豆蟹科最低(6.25)。黄渤海甲壳类的平均分类差异指数(Δ+)明显小于鱼类(P < 0.05)。2010-2015年调查的Δ+计算值高于理论值, 且在理论值的95%置信区间内, 说明黄渤海甲壳类群落正处在中等程度的干扰中。  相似文献   
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