Search results for "botany"
showing 10 items of 4586 documents
Xanthium strumarium - a potential cheap resource of plant substances for medicinal use
2019
Xanthium strumarium L. (Asteraceae) is an annual herb which reproduces solely by seed. So far its centre of origin was considered Central or South America. Recent archeological research revealed that the burs of X. strumarium were used in Yuergou site (400-200 cal BC) in the Turpan Basin of northwestern China. This plant adventive to Europe reduces germination of various crops and behaves like and aggressive invasive species. X. strumarium is the most frequently recorded plant in the field borders between the crop land and adjacent territories the agricultural areas in Bulgaria. We aim of this study is to reveal the potential of X. strumarium as a cheap source of compounds with valuable pha…
Molecular markers reflect differentiation of Fusarium oxysporum forma speciales on tomato and forma on eggplant
2013
Selective pressure induces pathogens to change their method of infection and, sometimes, causes species to become infectious. Pathogenic fungi must differentiate different morphological and physiological properties during the process of host specialization in their life cycle. In the present study, we conducted a genetic investigation and compared similarities within a generation of Fusarium oxysporum forma speciales (f. sp.) infecting tomato and forma (f.) infecting eggplants using selected ISSR and RAPD markers, two horticultural commodities belonging to the same taxon of the Solanaceae. Interestingly, genetic data showed that fungi belonging to F. oxysporum f. sp. infecting tomato have a…
Rapid radiation of North American desert genera of the Papaveraceae: Evidence from restriction site mapping of PCR-amplified chloroplast DNA fragments
1995
Phylogenetic relationships of a group of North American desert genera of the Papaveraceae subfam. Papaveroideae and Platystemonoideae were investigated with an RFLP analysis of three PCR-amplified chloroplast genome regions. In agreement with earlier results it was found that subfam. Platystemonoideae is nested within subfam. Papaveroideae. The group under study is characterized by a large number of generic autapomorphies but only few informative synapomorphies. This is interpreted as strong evidence for a rapid radiation event caused by major climatic changes in the past. Poor phylogenetic resolution seems to reflect biological reality and not to be an experimental artifact. There is also …
Unisexual flowers as a robust synapomorphy in Cariceae (Cyperaceae)? Evidence for bisexual flowers in Schoenoxiphium
2012
Abstract Cariceae, the largest tribe within Cyperaceae, comprises about 2000 species in five genera. Cariceae is usually considered to be distinct from other Cyperaceae by the presence of exclusively unisexual flowers and by the arrangement of the pistillate flowers in single-flowered spikelets that are enclosed by the flask-like spikelet prophyll (utricle or perigynium). The nature of several morphological features of the Cariceae inflorescence remains controversial. The staminate reproductive units, as well as earlier reported bisexual reproductive units in Schoenoxiphium have been considered to be reduced partial inflorescences, or flowers. Aims of this study are to test both interpretat…
18S rDNA phylogeny and evolution of cap development in Polyphysaceae (formerly Acetabulariaceae; Dasycladales, Chlorophyta)
2003
Abstract Cells of the members of the Dasycladales have a unique body plan well known from fossils. They persist today in 38 recognized species. This study investigates in detail the development of reproductive structures in 17 Polyphysaceae (= Acetabulariaceae) species and provides a molecular phylogenetic analysis of 18S ribosomal DNA sequence data of 23 species of the order Dasycladales, including 17 of the 19 extant members of the family Polyphysaceae. Reproductive cap development is documented by scanning electron microscopy in 17 species, by histological sections in five species, and by growth measurements. Other morphometric data are also provided for most species. Bayesian analysis o…
Syntaxonomical survey of Geranio-Cardaminetalia hirsutae: Semi-natural therophytic vegetation of the Mediterranean region
2007
A syntaxonomical scheme, including geographical range and synonymies of all the associations ascribed to Geranio-Cardaminetalia hirsutae, is presented. This order, framed into the class Stellarietea mediae, groups sciaphilo-subnitrophilous annual vegetation of natural and semi-natural habitats, commonly occurring on substrata rich in organic matter, accumulating on stone-walls, shaded rocks and initial soils, often under the canopy of shrubs and trees. Twelve new associations from Sardinia, Sicily, Egean islands and Israel are here described for the first time.
The bryophyte flora of Lågskär - An isolated island in the Baltic Sea
2014
This study reports the bryophyte flora of Lågskär, an isolated lighthouse island in the Åland province of Finland. A total of 81 bryophyte species were found on Lågskär, including 74 moss species and seven liverwort species. Syntrichia ruraliformis is reported for the first time in Finland, whereas Ceratodon conicus was believed to be extinct in Finland and Brachythecium turgidum was considered regionally extinct from southern Finland. peerReviewed
<p><strong>A new type designation of <em>Thymus microphyllus</em>, basionym of <em>Micromeria</em> <em>micr…
2020
Micromeria Bentham (1829: sub t. 1282) (Lamiaceae) is a monophyletic and taxonomically intricate genus, represented by nearly 70 species. These are distributed from the Macaronesian-Mediterranean region to southern Africa, India, and China (Morales 1991b, Govaerts 1999, Harley et al. 2004, Bräuchler et al. 2005, 2008; Puppo & Meimberg 2015, Puppo et al. 2014, 2015).
The role of hybridization in the evolution ofCousinias.str.(Asteraceae, Cardueae)
2009
Abstract Mehregan I. & Kadereit J. W.: The role of hybridization in the evolution of Cousinia s.str. (Asteraceae, Cardueae). — Willdenowia 39: 35–47. — Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39102 (available via http://dx.doi.org/) In order to assess the possible role of interspecific hybridization for the evolution of the high diversity of Cousinia subg. Cousinia (Cousinia s.str., c. 600 species), we examined the frequency of hybridization in this taxon. For this, hypothetical hybrid combinations published in the literature (28 putative hybrids and 11 intermediate forms) were critically examined. In addition, two hybrids were identified in the present study by …
Systematics, Phylogeny, and Evolution of Papaver californicum and Stylomecon heterophylla (Papaveraceae)
2011
Abstract We present a detailed comparison of Papaver californicum and Stylomecon heterophylla, which earlier were found to be sister species and most closely related to Meconopsis cambrica + Papaver s.str. from western Eurasia. The two species of winter annuals differ mainly in the shape of their distal cauline leaves, coloration of petals and staminal filaments, and most notably morphology of the gynoecium and capsule, with Papaver californicum having a sessile stigmatic disc and Stylomecon heterophylla having a distinct style. They were earlier found to differ in ploidy, with chromosome numbers of 2n = 28 (Papaver californicum) and 2n = 56 (Stylomecon heterophylla). Mapped distributio…