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The genus Fascicularia Mez is revised as part of a study of the Bromeliaceae for the Flora de Chile. Morphological and anatomical investigation of herbarium and living material from cultivation as well as DNA-studies (RAPDs) in cultivated material has led us to conclude that Fascicularia bicolor (Ruiz & Pav.) Mez, the only one species in the genus, comprises two subspecies which are distinguished by their leaf anatomy and morphology.  相似文献
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Wang ZQ 《Annals of botany》2004,94(2):281-288
BACKGROUND AND AIMS: The order Gnetales has been the central focus of controversy in seed plant phylogeny. Traditional treatment of morphology supports the anthophyte hypothesis with Gnetales sister to angiosperms but current molecular data reject this hypothesis. A new fossil gnetalean cone, Palaeognetaleana auspicia gen. et sp. nov., is reported from the Upper Permian in North China, and its phylogenic implications are considered. METHODS: Samples of cones from the upper part of the Upper Permian redbeds of Baode section, northwestern Shanxi Province, China, were examined. KEY RESULTS: The cone is characterized by its unusual nature of reproduction that combines features of post-Triassic gnetaleans and some of the Palaeozoic conifers. It is made up of a number of imbricate axillary units, each simply formed by an ovule and a subtending bract, which may be comparable with the axillary seed-scale complex of some of the Palaeozoic conifer cones. The cone exhibits at least a partially bisexual character that appears to have pollen sacs with monosulcate ribbed pollen grains and sessile, asymmetric, and radiospermic ovules. The ovule has an integument of three envelopes: an outer one of pointed scales; a middle sclerified one; and an inner cuticle that extends upward into a micropyle with an oblique tip. CONCLUSIONS: The new Permian cone has unequivocal affinity with the Gnetales. The fossil has considerably extended the divergence time of the Gnetales from 140 (210?) back to 270 myr ago and, therefore, provides the first significant fossil evidence to support the current conclusion based on molecular data of seed plants, i.e. monophyletic gymnosperms, comprising the Gnetales are closely related to conifers.  相似文献
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Capsella comprises diploid (C. grandiflora andC. rubella) and tetraploid taxa. It is argued that the tetraploidC. bursa-pastoris is of intraspecific origin despite disomic inheritance and fixed heterozygosity. It is of considerable age as evidenced by the fossil record and molecular data. Gene duplication by polyploidization and a mixed mating system provided the genetic flexibility for greatest colonizing success. Pronounced variation patterns at a micro- and macrogeographic scale are observed inC. bursa-pastoris for many characters including life history traits, leaf morphology and allozymes. This variation pattern can be explained by several components comprising phylogenetic age, random processes, ecotypic variation and colonization history. The adaptive strategy ofC. bursa-pastoris cannot be assigned to either ecotypic differentiation or phenotypic plasticity alone. It depends on the trait under study.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday  相似文献
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近年浙江省杭州市余杭区温室大棚内番茄灰叶斑病发生为害严重,对当地番茄生产造成了较大的经济损失,但该病害的病原菌种类尚未在浙江报道.本文通过对病原菌形态学、分子系统学(rDNA-ITS、gpd和EF-1α基因的PCR扩增、序列分析和系统进化树的构建)和致病性测定相结合的研究,将侵染番茄的病原菌鉴定为番茄匍柄霉菌Stemphylium lycopersici.研究结果对制定该病害的防治决策和有效防治提供了科学理论依据.  相似文献
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Giribet, G. 2010. A new dimension in combining data? The use of morphology and phylogenomic data in metazoan systematics. —Acta Zoologica (Stockholm) 91 : 11–19 Animal phylogenies have been traditionally inferred by using the character state information derived from the observation of a diverse array of morphological and anatomical features, but the incorporation of molecular data into the toolkit of phylogenetic characters has shifted drastically the way researchers infer phylogenies. A main reason for this is the ease at which molecular data can be obtained, compared to, e.g., traditional histological and microscopical techniques. Researchers now routinely use genomic data for reconstructing relationships among animal phyla (using whole genomes or Expressed Sequence Tags) but the amount of morphological data available to study the same phylogenetic patterns has not grown accordingly. Given the disparity between the amounts of molecular and morphological data, some authors have questioned entire morphological programs. In this review I discuss issues related to the combinability of genomic and morphological data, the informativeness of each set of characters, and conclude with a discussion of how morphology could be made scalable by utilizing new techniques that allow for non‐intrusive examination of large amounts of preserved museum specimens. Morphology should therefore remains a strong field in evolutionary and comparative biology, as it continues to provide information for inferring phylogenetic patterns, is an important complement for the patterns derived from the molecular data, and it is the common nexus that allows studying fossil taxa with large data sets of molecular data.  相似文献
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Despite their diversity and ecological importance, many areas of the SAR—Stramenopila, Alveolata, and Rhizaria—clade are poorly understood as the majority (90%) of SAR species lack molecular data and only 5% of species are from well‐sampled families. Here, we review and summarize the state of knowledge about the three major clades of SAR, describing the diversity within each clade and identifying synapomorphies when possible. We also assess the “dark area” of SAR: the morphologically described species that are missing molecular data. The majority of molecular data for SAR lineages are characterized from marine samples and vertebrate hosts, highlighting the need for additional research effort in areas such as freshwater and terrestrial habitats and “non‐vertebrate” hosts. We also describe the paucity of data on the biogeography of SAR species, and point to opportunities to illuminate diversity in this major eukaryotic clade. See also the video abstract here: https://youtu.be/_VUXqaX19Rw .  相似文献
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The similarity of lichenized fungal species composition among the 35 floristic regions recognized by Takhtajan was calculated, based on checklists of 132 geographical units and a first draft of a global checklist of lichens and allied fungi (which lists 18,882 species) to assess biogeographic and biodiversity patters of lichenized fungi. A nearest-neighbour cluster analysis of pair-wise comparisons of species composition data (Jaccard index of similarity) from these geographical units is presented. Four main geographical regions were identified: holarctic, subantarctic/Australian, oceanian, and pantropical. Possible changes of the global species number caused by increasing availability of molecular data are discussed. A prospect on future developments of lichen biodiversity research is provided.  相似文献
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Oreocharis duyunensis Z.Y. Li, X.G. Xiang et Z.Y. Guo (Gesneriaceae), endemic to Guizhou, China, is described as a new species. The new species is easily distinguished from other Oreocharis species by having a white, stellate ring‐like disc. Morphologically, the species is similar to Oreocharis chienii (Chun) Mich. Möller & A. Weber but differs by its densely white pilose leaves, mixed brown‐pilose, pubescent and glandular‐pubescent peduncle and pedicle, white stellate ring‐like disc, and linear‐lanceolate capsule. Based on phylogenetic reconstruction and interspecific genetic distances of nuclear ITS and chloroplast trnL‐F regions, O. duyunensis is a new species with uncertain phylogenetic position.  相似文献
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