Search results for "Callus"
showing 10 items of 63 documents
Adventitious shoot regeneration from hypocotyl cultures of service tree(Sorbus domesticaL.)
1992
Effects of growth regulators and N03:NH4 ratio were investigated to determine the mor- phogenic capacity of hypocotyl explants of service tree (Sorbus domestica L.) Organogenic responses were preceded by an initial callus phase and depended mainly on the auxin type used. NAA induced root differentiation whereas IAA added to media containing BA promoted adventitious shoot regeneration. Best results were obtained with 2.5 μM each of BA and IAA (19% of caulogenic explants). This reponse was increased (up to 44%) by varying nitrate to ammonium ratio from 2:1 to 4:1.
Somatic embryogenesis and plant regeneration in a woody species: the European Spindle Tree (Euonymus europaeus L.).
1993
Somatic embryogenesis and subsequent plant regeneration of Euonymus europaeus L (European Spindle Tree) were obtained from square pieces of mature zygotic embryos with an intervening callus phase. Callus and somatic embryos were induced using a Murashige and Skoog's semi-solid basal medium supplemented with several combinations of auxins and cytokinins. The greatest number of somatic embryos was obtained with a continuous exposure to 22.8 μM indoleacetic acid and 0.046 μM kinetin. The frequency of somatic embryogenesis from zygotic embryos depends on the cold conservation time of seeds. The embryos frequently germinated on the same medium. Further development of somatic embryos into plantle…
Untersuchungen zur Biosynthese eines Cytokinins in Calluszellen von Laubmoossporophyten
1973
When callus cells derived from the sporogon of the hybrid Funaria hygrometrica x Physcomitrium piriforme are supplied with adenine-8-14C, they produce a labelled cytokinin which has the same chromatographic behavior as N6-γγ-(dimethylallyl)aminopurine. The cytokinin is the first radioactive product that can be detected in the culture medium. It is formed as long as labelled adenine is available. When callus cells are grown in an optimum culture medium containing amino acids, about 10% of the radioactivity supplied as adenine is found in the cytokinin. When the cells are grown in a medium without amino acids, the RNA-content of the cells and the total yield of cytokinin decrease, but about 1…
The apparent loss of tissue culture competence during leaf differentiation in yams (Dioscorea bulbifera L.)
1993
Explants taken from the leaves of yams (Dioscorea bulbifera L.) at different stages of development were cultured in vitro on a checkerboard using various combinations and/or concentrations of auxin (2,4-d) and cytokinin (6-BAP). An addition of cytokinin to the culture media was not essential for callus induction from explants derived from young leaves in the very early stages of expansion. When the leaves expanded further they required cytokinin and the requirement increased considerably during expansion. Explants taken from fully expanded leaves were no longer able to proliferate, even when extremely high concentrations of cytokinins were applied. Callus grown from highly immature leaves w…
Morphogenic potential of mechanically isolated single cells from Digitalis obscura L. callus
1989
Calli from hypocotyl and root explants of Digitalis obscura L. showed regeneration of adventitious shoots, roots and embryos when transferred to Murashige & Skoog medium supplemented with cytokinins alone or in combination with auxins. Optimum shoot-bud formation was achieved in the presence of IAA and BA, while roots mainly appeared either in absence of growth regulators or with IAA and Kn. Embryo formation took place only in those combinations that included Kn. Embryo development was influenced by the type of auxin, and precocious germination occurred in media with NAA. Mechanically isolated cells from hypocotyl- and root-derived calli were plated in MS medium supplemented with several IA…
Morphogenesis in callus and single-cell cultures ofLavandula latifoliaMedicus
1990
Procedures and factors promoting plant regeneration from callus and isolated cells were investigated in Lavandula latifolia Medicus. Callus was obtained from cotyledon explants cultured on MS medium supplemented with 0.34 (xM 2,4-D. These calli regenerated adventitious buds when transferred to MS medium containing either BA or several auxin (IAA or NAA)/BA combinations, best results being obtained in the presence of 8.80 (mi BA alone or in combination with 0.06 and 0.60 (xM IAA or NAA. Single cells from cotyledon-derived calli were able to proliferate as callus when plated in MS medium supplemented with IAA or several IAA/BA combinations. Best plating efficiency was achieved when cells were…
In vitro morphogenesis of grapevine (Vitis vinifera L.) inflorescence primordia, cvs Pinot Noir and Chardonnay
1998
Hormonal regulatory processes controlling in vitro morphogenesis of grapevine inflorescence primordia, excised from latent buds from November to April, were investigated. Cytokinin (benzylaminopurine, BAP), gibberellin (GA3) and auxin (3-indolebutyric acid, IBA) were used at 1 mg/L. BAP induced branch development and flower calyx differentiation. GA3 first promoted the elongation of inflorescence rachis and then promoted flower differentiation up to the formation of normal calyx and calyptra (the fused petals), while anthers and pistils were also present but not functional. IBA did not seem to be directly involved in these morphogenetic processes. After culturing for 6–7 weeks, explants bec…
Correlated response of in vitro regeneration capacity from different source of explants inCucumis melo.
1994
The variation among and within different populations of the regeneration ability from leaf, cotyledon and hypocotyl explants has been studied. A control population and two lines selected by their regeneration capacity from leaf explants were used. Significant differences among the plants of the control population,for the organogenic response, were detected. The regeneration capacity varies depending on the type of explant. Selection in order to improve the regeneration frequency from leaf explants also raises the organogenic response in the other explant types. This result suggests the presence of a partial common genetic system controlling the regeneration frequency of the diverse types of…
�ber den Nachweis eines Neurohormones beim Laubmooscallus und seine Beeinflussung durch das Phytochrom
1971
The presence of a neurohormone in moss callus could be demonstrated by means of pharmacological experiments on the heart of the frog (Rana temporaria L.) and by chromatography.The hearts react in the same manner as they do to application of acetylcholine and the substance resembles acetylcholine in its Rf-value. Therefore it is suggested that this hormone is identical with acetylcholine. The concentration of the hormone in the callus cells is mediated by the phytochrome. Moss callus cultivated under red and far-red illumination contain less substance than moss callus grown in red light.
Hyperplastic callus formation in osteogenesis imperfecta: CT and MRI findings.
1998
Hyperplastic callus formation is a noteworthy condition in patients with osteogenesis imperfecta because it often mimicks osteosarcoma on radiography. The findings of CT and MRI in hyperplastic callus formation have not been reported. In the presented case, MRI demonstrated contrast enhancement and edema of the surrounding soft tisssue, consistent with benign as well as malignant disease. Computed tomography showed a calcified rim of the lesion which may be a useful feature to rule out osteosarcoma in this condition.