Search results for "Phylogenetics"
showing 10 items of 777 documents
Characterization of Alternaria alternata Isolates from Tangerine Hybrids Affected by Brown Spot in Italy
2011
Alternaria brown spot, caused by Alternaria alternata, is the most important disease of tangerines and their hybrids worldwide, including Italy. The disease represents, for some susceptible citrus cultivar, a limiting factor in profitable cultivation. The results of the characterization of A. alternata isolates obtained from lesions on leaves and fruits of Fortune, Nova and Winola hybrids and Valencia sweet orange, collected in two groves located in Calabria and Sicily, is reported. An endopolygalacturonase gene (endoPG) was sequenced from five representative strains and a phylogenetic tree based on endoPG sequence data of Italian isolates and those of citrus associated Alternaria species d…
The complete nucleotide sequence of an isolate of Tomato yellow leaf curl Sardinia virus found in Sicily
2010
Partial sequences of Tomato yellow leaf curl Sardinia virus (TYLCSV) derived from tomato samples collected in Sicily in 1999, 2002 and 2004 indicated the presence of a TYLCSV different from the one previously described as the Sic strain. Here, we report a complete DNA sequence that is classified as belonging to the TYLCSV type strain (Sar strain), confirming the co-existence in Sicily of virus populations of both strains. Moreover, comparisons between this new sequence and those of the two recombinants recently described in Sicily revealed unequivocally (99% identity) that their TYLCSV-derived portion originated from the Sar strain. © 2010 Springer-Verlag.
The taxonomic position of Roesleria subterranea
2006
The genus Roesleria was introduced with the single species Roesleria hypogaea (current name: R. subterranea) by Thümen in 1877. The species was originally described from roots of grapevine and recognised as a facultative root-rotting parasite. The mazaediate ascoma with evanescent asci led to the assumption that Roesleria would be an ally of mazaediate lichens. In this study we calculate 28S, 18S as well ITS1-5.8S-ITS2 rDNA phylogenies. These data indicate that Roesleria is closely related to Hymenoscyphus (Helotiales). In contrast to other members of the Helotiales, the ascospores of Roesleria are passively released, and a distinct apical apparatus cannot be observed by LM. Electron optic …
Two new combinations inAdenostyles (Asteraceae, Senecioneae), a conspectus of the genus and key to its species and subspecies
2012
Abstract Dillenberger M. S. & Kadereit J. W.: Two new combinations in Adenostyles (Asteraceae, Senecioneae), a conspectus of the genus and key to its species and subspecies. — Willdenowia 42: 57-61. June 2012. — Online ISSN 1868-6397; © 2012 BGBM Berlin-Dahlem. Stable URL: http://dx.doi.org/10.3372/wi.42.42105 Based on a molecular phylogeny (using ITS, ETS and the rpl32-trnL, psbA-trnH and ndhF-rpl32 plastid spacer sequences) of all species and subspecies of the European genus Adenostyles currently recognised, and supported by the morphology of the leaf margin, we transfer two subspecies of A. alliariae to A. alpina and provide the new combinations A. alpina subsp. macrocephala and A. alpin…
Patterns and causes of incongruence between plastid and nuclear Senecioneae (Asteraceae) phylogenies
2010
One of the longstanding questions in phylogenetic systematics is how to address incongruence among phylogenies obtained from multiple markers and how to determine the causes. This study presents a detailed analysis of incongruent patterns between plastid and ITS/ETS phylogenies of Tribe Senecioneae (Asteraceae). This approach revealed widespread and strongly supported incongruence, which complicates conclusions about evolutionary relationships at all taxonomic levels. The patterns of incongruence that were resolved suggest that incomplete lineage sorting (ILS) and/or ancient hybridization are the most likely explanations. These phenomena are, however, extremely difficult to distinguish beca…
Interrelationships of the Haploporinae (Digenea: Haploporidae): A molecular test of the taxonomic framework based on morphology
2009
The taxonomic framework of the Haploporidae is evaluated and the relationships within the Haploporinae are assessed for the first time at the generic level using molecular data. Partial 28S and complete ITS2 rDNA sequences from representatives of six of the nine recognised genera within the Haploporinae were analysed together with published sequences representing members of two haploporid subfamilies and of the closely related family Atractotrematidae. Molecular analyses revealed: (i) a close relationship between the Atractotrematidae and the Haploporidae; (ii) strong support for the monophyly of the Haploporinae, Dicrogaster and Saccocoelium, and the position of Ragaia within the Haplopori…
Comparative analysis of leaf shape development inEschscholzia californicaand other Papaveraceae-Eschscholzioideae
2011
Dissected leaves in Papaveraceae-Eschscholzioideae have an architecture frequently encountered in the basal eudicot clade Ranunculales that could represent an ancestral condition for eudicots. Developmental morphology of foliage leaves was investigated using scanning electron microscopy and focusing on primordium formation activity (primary morphogenesis) at the leaf margin. Eschscholzia californica, E. lobii, and Hunnemannia fumariaefolia had a polyternate-acropetal mode of leaf dissection. Segment formation continued around the whole leaf blade periphery. Differences in mature leaf architecture was traced to variations in regional blastozone activity and duration. Epidermal cell size meas…
Augu nosaukumu autori
2021
Raksts satur informāciju par Latvijas Universitātes Muzeja Botānikas un mikoloģijas kolekciju herbārija bibliotēkas krājumā esošo Ričarda Kenneta Brammita un Emmas Pouelas monogrāfiju “Augu nosaukumu autori: augu zinātnisko nosaukumu autoru saraksts ar ieteicamajām to nosaukumu formām, ieskaitot saīsinājumus” (Authors of plant names: a list of authors of scientific names of plants, with recommended standard forms of their names, including abbreviations) un tajā aprakstīto uzvārda “standarta formu” augu nosaukumu autoriem piešķiršanas procesu 20. gs. 80.-90. gados.
Applied Anatomy of the Cerebral Arteries
1991
Four arteries supply the brain with blood: the two carotid and the two vertebral arteries. Although these four vessels are ultimately interlinked via a basal arterial network, the circle of Willis, and anastomoses at the brain surface, Heubner’s anastomoses, it is useful to distinguish anterior (carotid anterior and middle cerebral) and posterior (vertebrobasilar posterior cerebral) vascular territories (Gillian 1957, 1968; Lazorthes 1961; Kaplan and Ford 1966; Ganshirt 1972; Seeger 1978; Dorndorf 1983; Duus 1983).
The ambiguous role of 2,4-dichlorophenoxyacetic acid in wheat tissue culture
1986
The very basal, highly immature regions of dissected young leaves of Triticum aestivum L. cv. Kite formed adventitious roots on a nutrient medium supplemented with comparatively low concentrations (0.16 to 0.63 μM) of 2,4-dichlorophenoxyacetic acid (2,4-D). Higher concentrations (up to 640 μM) had to be applied to stimulate growth from more mature regions higher up the leaf. Yet, already at 2.5 μM roots were less distinct and more callus-like, and eventually (at 10 to 640 μM) only a subculturable callus of apparently suppressed, slowly proliferating root primordia developed. Furthermore, at the most basal, highly immature regions growth was significantly retarded when the auxin concentratio…