Search results for "Callu"
showing 10 items of 70 documents
From the Strait of Gibraltar to northern Europe: Pleistocene refugia and biogeographic history of heather (Calluna vulgaris, Ericaceae)
2021
Abstract Calluna vulgaris (Ericaceae) is the most widespread and prevalent woody species of the European dry heathland, from the African side of the Strait of Gibraltar to northern Europe. However, previous biogeographic analyses of this species have ignored the western Mediterranean region, despite its preponderant role as a major glacial refugium for European biota. Here, we explore the existence of further Pleistocene glacial refugia for C. vulgaris in the Iberian Peninsula and the Strait of Gibraltar area and provide new insights into the post-glacial colonization of Europe by this emblematic heathland species. We carried out phylogeographical analyses of C. vulgaris samples from 44 loc…
Plant regeneration from isolated cells ofLavandula latifolia medicus
1988
Single cells were obtained from hypocotyl-derived callus ofLavandula latifolia Medicus. Cells were plated in Murashige and Skoog medium supplemented with indoleacetic acid (IAA), benzyladenine (BA), and several IAA-BA combinations. Cell division required the simultaneous presence of IAA and BA in the culture medium, but callus formation was only achieved with 0.1 or 1 mg/liter IAA and 2 mg/liter BA. To induce organogenesis, calli were transferred to various regeneration media. Shoot-bud differentiation efficiency depended on the composition of both the callus induction and the shoot regeneration media, best results being obtained when calli grown in 1 mg/liter IAA and 2 mg/liter BA were sub…
In vitro morphogenesis from excised leaf explants of Digitalis obscura L.
1984
The morphogenic capacity of Digitalis obscura leaf explants cultured in vitro has been studied, noting factors promoting the differentiation of roots, buds and shoots as well as those promoting callus proliferation. Complete plant regeneration was obtained only by first culturing the leaf explants in a medium with NAA and BA to induce formation of buds, and subsequently transferring them to a medium without growth regulators to achieve the further development of shoots.
Biologically Active Triterpene Saponins from Callus Tissue of Polygala amarella
1999
A new bioactive saponin (1), together with a known saponin (polygalasaponin XXVIII) has been isolated from the callus tissue culture of Polygala amarella. Based on spectroscopic data, especially direct and long-range heteronuclear 2D NMR analysis and on chemical transformations, the structure of 1 was elucidated as 3-O-beta-D-glucopyranosyl presenegenin-28-O-beta-D-galactopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-fucopyranoside. Both saponins showed significant immunological properties based on the enhancement of granulocyte phagocytosis in vitro.
Purification and identification of a cytokinin from moss callus cells.
1976
A cytokinin was isolated from the culture medium of callus cells of the moss hybridFunaria hygrometrica (L.) Sibth xPhyscomitrium piriforme Brid. The purification procedure included ethyl-acetate extraction, silver-salt precipitation, crystallization as picrate, and ion exchange chromatography. The structure of the cytokinin was confirmed as N(6)-(Δ(2)-isopentenyl)adenine by means of gas chromatography and mass spectrometry. The concentration of the compound in the culture medium was determined at ca. 10(-6) M.
Somatic embryogenesis and plant regeneration from pistil thin cell layers of Citrus
1999
Callus induction, somatic embryogenesis and plant regeneration were obtained in six different citrus species [Citrus deliciosa Ten. (cv 'Avana'), C.limon (L.) Burm. (cv 'Berna'), C.madurensis Lour. (cv 'CNR P9'), C.medica L. (cv 'Cedro di Trabia'), C.tardiva Hort. ex Tan. (cv 'CNR P6'), C.sinensis (L.) Osb. (cv 'Ugdulena 7')] from cultures of pistil transverse thin cell layer explants [(t)TCL]. Explants were cultured on three different media: the nutrients and vitamins of Murashige and Skoog medium alone (MS) or MS supplemented with either 500 mg l(-1) malt extract (MS I) or 500 mg l(-1) malt extract and 13.3 mu M 6-benzylaminopurine (MS II). Sucrose (146 mM) was used as the carbon source. …
Constituents of regenerated plants of Ophiorrhiza pumila; formation of a new glycocamptothecin and predominant formation of (3R)-deoxypumiloside over…
1997
Abstract The regeneration of plantlets was successful from Ophiorrhiza pumila callus cultures, from which a new glucosyloxy camptothecin, 9-β-glucosyloxycamptothecin, together with 15 metabolites including six camptothecin-related alkaloids was isolated. (3S)-Deoxypumiloside, one of the plausible biogenetic precursors of camptothecin, could not be found, whereas the (3R) epimer was isolated from the regenerated plants.
Histoincompatibility reactions in the hydrocoral Millepora dichotoma
1983
The xenogeneic- and allogeneic immunological specificity of the hydrocoral Millepora dichotoma has been investigated. Xenogeneic histoicompatibility reactions have been observed between this hydrocoral and a series of species belonging to the Demospongiae and to the Anthozoa (both Hexacorallia and Octocorallia). The xenogeneic histoincompatibility reactions proceed in the following sequence: (a) Species-unspecific sensitization; (b) necrosis formation, which is very likely due to an autolytic process; (c) callus formation, due to an hyperplastic growth of stolons; and (d) formation of a contact barrier in form of a barrier layer or a restored stolonial layer. Allogeneic histoincompatibility…
Somatic embryogenesis in Abies nebrodensis, an endangered Sicilian fir
2022
AbstractSomatic embryogenesis, as a promising biotechnological tool for many conifer trees, has never been applied for the Abies nebrodensis species. Although all the encouraging results previously obtained by the EU LIFE (European LIFE program) funded projects in over ten years, the critically endangered Sicilian fir remains alarmingly close to extinction. In this study, we reported the first protocol of somatic embryogenesis obtained from mature zygotic embryos of the Abies nebrodensis. Seeds from Abies adult trees with specific identification numbers (IN) were collected and full seeds were identified by X-ray. Different experiments were carried out for callus initiation, from both zygoti…
Cryopreservation of Limonium serotinum apical meristems from in vitro plantlets using droplet-vitrification
2011
Abstract In this study in vitro shoot tips of a Sicilian genotype of Limonium serotinum were successfully cryopreserved using the droplet-vitrification technique. Growth recovery of cryopreserved shoot tips was possible only when samples were pretreated for 16 h in liquid medium with 0.3 M sucrose, then for 5 h in liquid medium with 0.7 M sucrose before performing the cryopreservation protocol. Optimal conditions included treatment for 20 min in a loading solution containing 1.9 M glycerol + 0.5 M sucrose, treatment with vitrification solution B5 (glycerol 40.0%, sucrose 40.0%, w/v) for 60 and 90 min or vitrification solution A9 (glycerol 30.0%, dimethylsulfoxide 20.0%, ethylene glycol 20.0…