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Taxonomic Characters (taxonomic + character)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

European Hornbeam Powdery Mildew Erysiphe arcuata in Slovakia

JOURNAL OF PHYTOPATHOLOGY, Issue 10 2008
K. Pastir, áková
Abstract Erysiphe arcuata found on European hornbeam (Carpinus betulus) is reported from Slovakia for the first time. Taxonomic characters of the anamorphic and teleomorphic states of E. arcuata were described and illustrated. Additionally, disease symptoms caused by this pathogen were presented. The identification of the fungus is based on morphological data combined with the results of a sequence analysis. [source]

The basidiomycete genus Polyporus , an emendation based on phylogeny and putative secondary structure of ribosomal RNA molecules

FEDDES REPERTORIUM, Issue 7-8 2004
D. Krüger
The fungal genus Polyporus is an assemblage of white-rotting lignicolous basidiomycetes. It has undergone considerable expansion and contraction over a period of two and three quarter centuries. Current generic circumscription of Polyporus has kept the genus non-monophyletic. Species of Polyporus infrageneric group Polyporellus are closely related to some species of Lentinus. We introduce data for ITS2 spacer rRNA secondary structure evolution by quasi-independent comparison with large subunit rRNA phylogeny, and suggest a fraction of primary nuclear rDNA ITS sequence data as novel taxonomic character. A major taxonomic shift is suggested, supported by molecular and morphological characters, and allowing inclusion of species with gilled hymenophores in Polyporus. Two new names are proposed: Polyporus phyllostipes D.Krüger, nom. nov. and Polyporus gerdai D.Krüger, nom. nov. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Die Gattung Polyporus (Basidiomycetes) , eine Emendation auf der Basis von Phylogenie und mutmaßlicher sekundärer Struktur der ribosomalen RNA-Moleküle Die Pilzgattung Polyporus, eine Gruppe Weißfäule erregender holzbewohnender Basidiomyceten, wurde über nahezu drei Jahrhunderte vielfach expandiert und verkleinert. Bei der derzeitigen Gattungsumschreibung von Polyporus gilt die Gattung als nicht-monophyletisch. Arten der Polyporus -Gruppe Polyporellus sind eng verwandt zu einigen Lentinus- Arten. Anhand quasi-unabhängigem Vergleich mit der Phylogenie der rRNA der großen Untereinheit (LSU) stellen wir Daten zur Evolution der ITS2 Spacer rRNA vor, und schlagen ein ITS Kern-rDNA-Fragment als taxonomisches Merkmal vor. Unterstützt mit molekularen und morphologischen Daten wird eine grundlegende taxonomische Verschiebung vorgeschlagen, welche Arten mit Lamellen-Hymenophoren in Polyporus erlaubt. Zwei neue Namen werden vorgeschlagen: Polyporus phyllostipes D.Krüger, nom. nov. und Polyporus gerdai D.Krüger, nom. nov. [source]

The endosymbiont community as taxonomic character: a novel approach to resolving the Bemisia tabaci complex

MOLECULAR ECOLOGY, Issue 19 2010
JULIE K. STAHLHUT
In this issue of Molecular Ecology, Gueguen et al. (2010) describe their novel approach to resolving cryptic genetic diversity in the Bemisia tabaci complex (Hemiptera: Aleyrodidae.) Complexes of cryptic species present a challenge to both morphological and molecular taxonomy , the former presumed, as shared morphology normally defines species as cryptic, but the latter also problematic when host DNA sequence data is either inconclusive or unaccompanied by independent evidence. Endosymbiont associations with insect hosts have, historically, complicated efforts to develop a robust molecular taxonomy, but the approach of Gueguen et al. takes advantage of endosymbiont community composition to help rather than hinder the task of resolving taxonomic distinctions within the B. tabaci complex. [source]

Seed morphology of Cuscuta L. (Convolvulaceae) in Egypt and its systematic significance

FEDDES REPERTORIUM, Issue 3-4 2006
K. N. Abdel Khalik
The seed morphology of eight taxa of Cuscuta from Egypt has been studied using light and scanning electron microscopy, to determine the significance of seed coat features as taxonomic characters. Macro- and micromorphological characters, including seed shape, colour, size, epidermal cell shape, anticlinal boundaries, outer periclinal cell wall and relief of outer cell walls are presented. Three types of anticlinal cell wall boundaries are recognized and two different shapes of outer periclinal cell wall are described. The secondary sculpture of the cell wall varies from striate to micro-reticulate, and smooth to fine folds. A key for the identification of the investigated taxa based on seed characters is provided. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Samenmorphologie von Cuscuta L. (Convolvulaceae) in Ägypten und ihre systematische Bedeutung Die Morphologie des Samens von acht ägyptischen Cuscuta -Taxa wurde mittels Licht- und Elektronenmikroskopie untersucht, um die Bedeutung der Merkmale der Samenschale für die Taxonomie zu ermitteln. Makro- und mikromorphologische Merkmale einschließlich Samengestalt, Farbe, Größe, Form der Epidermiszellen, antiklinale Zellwände, äußere Periklinal-Zellwände und Relief der äußeren Zellwände umfassend, wurden untersucht. Drei Typen antiklinaler Zellwand-Umrisse und zwei unterschiedliche Formen der äußeren Periklinal-Zellwände werden beschrieben. Die sekundäre Skulptur der Zellwände variiert von striat bis mikro-reticulat, und von glatt zu leicht gefaltet. Ein Bestimmungsschlüssel basierend auf den Samenmerkmalen der untersuchten Sippen wird vorgelegt. [source]

The separation of Pterodroma madeira (Zino's Petrel) from Pterodroma feae (Fea's Petrel) (Aves: Procellariidae)

IBIS, Issue 2 2008
FRANCIS ZINO
The taxonomic status of petrels from the North East Atlantic has long been a matter of debate. Breeding colonies of petrels occurring on the islands of Madeira, Bugio and Cape Verde were originally thought to be outlying populations of the polytypic species Pterodroma mollis. Subsequent taxonomic treatments have varied considerably in their classification of birds from these islands. The petrel populations on Madeira and Bugio represent some of Europe's rarest breeding birds and their exact species designation, and hence relation to conservation mandates, is a question of considerable importance. In this study we use molecular techniques alongside more traditional taxonomic characters to confirm the existence of two species of the genus Pterodroma in the Archipelago of Madeira. We also discuss identification of these species in the field and the implications for their conservation management. [source]

Comparative morphology of the leaf epidermis in Schisandra (Schisandraceae)

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2005
ZHI-RONG YANG
The leaf epidermis of 127 samples representing ten species within Schisandra Michaux. and one species of the related genus, Kadsura Kaempf. ex Juss., was investigated using light and scanning electron microscopy. Many characters of the leaf epidermis in Schisandra, such as pattern of epidermal cells, type of stomata, shape of guard cell pairs and cuticular ornamentation, are usually constant within species and thus make good characters for studying the relationship between and within genera. A new character, rim number, of the outer stomatal rim in the genus is introduced. It is shown that double outer stomatal rims occur only in evergreen Schisandra species, whereas a single rim occurs in deciduous species. This character supports the classification of Schisandra into two subgenera based on habit and androecial organs. This classification is also supported by additional morphological and molecular taxonomic characters. Kadsura coccinea (Lem.) Smith A. C. is the most primitive taxon in the related genus Kadsura. The outer stomatal rim of this species also has double rims. Combined with morphological and molecular evidence, this suggests that Schisandra and Kadsura are closely related and may share a recent common ancestor. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 148, 39,56. [source]