Search results for "Stamen"
showing 10 items of 612 documents
The perfume flowers ofCyphomandra (Solanaceae): Pollination by euglossine bees, bellows mechanism, osmophores, and volatiles
1993
The perfume syndrome and pollination by fragrance-collecting euglossine bees in the neotropic solanaceous genusCyphomandra was confirmed by field observations. In SE Brazil,C. sciadostylis was visited byEufriesea violaceae, andC. diploconos byEuglossa mandibularis; C. hartwegii was pollinated byEulaema meriana in Costa Rica. The primary attractant, fragrant droplets that ooze from the dorsally bulged connectives, is mopped up by the males with the forebasitarsi. Thereby, the poricidal thecae are inadvertently pushed causing the dry pollen to dust the bee's sternum. The number and direction of the pollen jets are related to pollinator size and stigma structure. The flowers are homogamous, se…
STUDIO PROPEDEUTICO PER LA REDAZIONE DI UN PIANO DI GESTIONE FORESTALE DEL BOSCO TARDARA, SUGHERETA PURA DEL COMUNE DI TUSA (MESSINA)
2019
La Sicilia è la seconda regione d’Italia per estensione delle formazioni naturali a Quercus suber (L.).Sugherete più o meno degradate sono presenti in tutte le province, il cui stato qualitativo oggi risulta carente a causa dei frequenti incendi, pascolo eccessivo e mancanza di adeguate cure colturali, ma certamente tra tutte le cause la principale è l’assenza di pianificazione. Da questa premessa affiora la necessità di conoscere e governare in modo congruo la superficie boscata siciliana attraverso la redazione di Piani di Gestione Forestale, mirando al ripristino dell’efficienza, della funzionalità e, in particolar modo, della produzione sostenibile dei boschi a sughera. Con il presente …
Effect of polyamines on in vitro anther culture of Citrus clementina Hort. ex Tan
2006
The improvement of the induction rate in Citrus anther culture is important for taking practical advantage of the haploid potential in breeding. The influence of polyamines on anther culture of Citrus clementina, cv Nules, with particular attention to the free, soluble and insoluble-conjugated polyamine levels, has been investigated. Putrescine, spermidine and putrescine plus spermidine, were added to the standard induction medium. Before culture, spermidine was the most abundant among the free polyamines detected in anthers. The exogenous supply of either putrescine or spermidine, either independently or combined, effected greater uptake and accumulation of polyamines. The addition of 2 mM…
The body fables in Babrius, Fab. 134 and 1 Corinthians 12: Hierarchic or democratic leadership in crisis management?
2021
Body metaphors and body fables were frequently used in ancient discourse for social communities and politics. This article will examine a body fable by the Greek fabulist Babrius (Babrius, Fab . 134) that has been overlooked in research so far. It shows a remarkable similarity to 1 Corinthians 12 through the use of central terms such as σῶμα and μέλος or personified speaking body parts such as an eye and head. Even if no literary direct dependence is claimed, the text, which was written at about the same time as 1 Corinthians, sheds light on Paul’s understanding of the body fable. It becomes apparent, however, that the rhetorical function is fundamentally different in the two texts. Whilst …
Floral Diversity and Pollen Transfer Mechanisms in Bird-pollinated Salvia Species
2007
† Background and Aims Bird-pollinated (ornithophilous) Salvia species (sages) transfer pollen either by means of a staminal lever mechanism or by immovable stamens. As the distribution of the two modes within the genus is not known, we present a survey of all ornithophilous sages. The main focus is given to floral diversity especially with respect to functional lever morphology. Thereby the hypothesis is tested that, due to a pollinator shift from bees to birds, the lever mechanism became unnecessary. † Methods To get a general idea about the diversity of pollen transfer mechanisms, 186 ornithophilous Salvia species were classified according to the functional morphology of the stamen and th…
Cambiamenti climatici, selvicoltura e popolamenti a rischio
2014
Il contributo prende in esame alcune criticità dei popolamenti al margine dell'areale di diffusione, in quanto soggetti a pressioni ecologiche a seguito del cambiamento climatico in atto. Si esaminano casi di studio e si indicano alcuni indirizzi colturali volti a ridurre gli stress e le criticità in atto
16. Ottimizzazione del campione dendrometrico
2009
Nell'ambito della redazione del Piano di Gestione della Riserva Naturale Statale biogenetica di Vallombrosa è stata condotta una sperimentazione volta a ottimizzare il tempo di rilievo e la dimensione del campione per il rilievo quantitativo dendrometrico. i risultati evidenziano che la migliore dimensione delle aree di saggio, di forma circolare, verificata sul CV dell'area basimetrica e nell'ottica di minimizzare i tempi di rilievo è pari a 1257 metri quadrati, ovvero un raggio di 20 metri lineari.
Soil carbon accumulation after agricultural abandonment. A Mediterranean case study.
2011
In the last decades, in Europe large agricultural areas have been abandoned. In absence of disturbance factors, renaturation of these areas is rapid due to secondary succession of vegetation communities. In the Mediterranean region, in the last years have been conducted studies on soil carbon accumulation after agricultural abandonment. Soil has to be regarded as the most considerable carbon (C) sink on a global level. CO2 emission compensation is guaranteed also by C uptake by plants and by organic matter accumulation in soils. The present study analyzes organic carbon stock in some soils of Southern Italy, in the Madonie Mountains in Sicily, where large areas are subject to secondary succ…
New and little known Cerambycidae (Coleoptera Chrysomeloidea) from Pantelleria Island (Sicily Channel, Italy)
2019
Cerambycidae (Coleoptera Chrysomeloidea) nuovi e poco conosciuti dell’isola di Pantelleria (Cana-le di Sicilia, Italia).In questa nota riportiamo nuovi dati di due specie di Cerambycidae raccolte sul-l’isola di Pantelleria (Canale di Sicilia, Italia). In particolare, la presenza di Trichoferus holosericeus(Rossi, 1790) è confermata e Cephalocrius syriacus(Reitter, 1895) è riportato come nuovo record
In vitro plant regeneration of caper (Capparis spinosa L.) from floral explants and genetic stability of regenerants
2011
A new technique to regenerate caper plants (Capparis spinosa L. subsp. rupestris) starting from flower explant is reported. In vitro plant regeneration was attempted using stigma, anthers and unfertilized ovules of unopened flowers collected in the field. Plant regeneration was achieved from unfertilized ovules on MS medium supplemented with 88 mM sucrose and 13 lM 6-benzyladenine (BA). New individuals obtained from unfertilized ovules were used as source material for micropropagation and multiple shoots were obtained on MS medium sup- plemented with the adeninic cytokinin BA and the auxin indole-3-butyric acid (IBA). Explants obtained in micro- propagation step were used for rooting step u…