Search results for "auxin"
showing 10 items of 81 documents
Morphogenesis in Root Tip Meristem Cultures of Digitalis obscura L.
1987
Summary The morphogenic capacity of Digitalis obscura L. root tip meristems cultured in vitro has been studied, noting hormonal factors inducing differentiation and development of shoots as well as those promoting somatic embryogenesis. Caulogenesis was obtained with different auxin/cytokinin combinations but a high rate of shoot regeneration was induced by 0.1 or 0.5 ppm IAA and 1.0 ppm BA. Different stages of somatic embryo development were observed in media supplemented with auxins or high auxin/cytokinin ratios, although no complete plant regeneration was achieved. This is the first report known of shoot regeneration from root tips of Digitalis obscura L.
Improved micropropagation in Polygala myrtifolia
2004
Stem segments from apical shoot tips of Polygala myrtifolia were used as primary explants to establish in vitro cultures. Axillary shoots produced on noncontaminated explants were excised and recultured in the same medium to increase the stock of shoot cultures. Equal molar concentrations of five cytokinins 2-isopentenyladenine (2iP), kinetin, zeatin, N6-benzyladenine (BA) and adenine were tested for ability to induce axillary shoot development from double node stem segments. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog agar medium supplemented with 1.8 M BA. Seven indole-3-acetic acid (IAA) concentrations (2.8, 5.7, 8.6, 11.4, 14.3, 17.1 M) were t…
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…
Plant regeneration from cultured leaves of Lavandula latifolia Medicus: Influence of growth regulators and illumination conditions
1989
Leaves were obtained from 4-week-old seedlings of Lavandula latifolia Medicus grown in vitro. Leaf explants were then cultured on MS medium supplemented with different concentrations and combinations of the auxins IAA or NAA with the cytokinin BA and maintained under three illumination conditions, 16h photoperiod, darkness or darkness followed by a photoperiod, to assess morphogenic responses. Irrespective of illumination conditions, bud regeneration was achieved only in media containing BA or BA/auxin combinations, with the best results being obtained in the presence of BA and 0.06 or 0.6 μM IAA or NAA. A photoperiod of 16h appeared to yield the best response in terms of bud regeneration p…
Factors affecting adventitious bud induction in Pinus elliottii (Engelm.) embryos cultured in vitro
1987
Embryos of slash pine (Pinus elliottii Engelm.) were induced to form adventitious buds when placed in culture on nutrient media supplemented with cytokinin. Buds were induced on media containing Risser & White major salts. The high content in nitrogen of Murashige & Skoog formulation seems to be deleterious for this in vitro system, since morphogenic responses were only promoted when nitrogen concentration was drastically reduced in the macronutrient formulation. Factors such as concentration of cytokinin (6-benzyladenine) and time and method of exposure (liquid or solid induction medium) strongly influenced bud formation and development. The greatest number of buds and shoots were obtained…
Cell wall xyloglucan incorporation by xyloglucan endotransglucosylase/hydrolase in pine hypocotyls
2004
Abstract In the present study, we have examined the incorporation of labelled xyloglucan oligosaccharides into the cell wall xyloglucan of pine hypocotyl sections, and the effect of plant hormones on the incorporation and on XTH enzyme activity (EC 2.4.1.207). Xyloglucan heptasaccharide [ 3 H ]XXXGol was absorbed, transported and incorporated into the cell wall xyloglucan of de-rooted pine hypocotyls. Incorporation of [ 3 H ]XXXGol into soluble and cell wall xyloglucan was induced by IAA, brassinolides and XXXG in pine hypocotyl segments. A relationship between growth induction, by IAA, brassinolides and XXXG, and both soluble and cell wall-bound XTH was found. We suggest that IAA induced-g…
Relationship between Auxin-Dependent Proton Extrusion and Plasmalemma Redox System in Maize Coleoptile Segments
1988
Abraded coleoptile segments reduce ferricyanide utilizing endogenous substrates. The kinetics of ferricyanide reduction shows an initial rapid rate followed by a slow rate of reduction. The duration of the initial phase is about 5 minutes. The slow phase is observed for more than 30 minutes. A Lineweaver-Burk plot of the slow phase was linear and revealed maximum velocity of the reaction of 42 nmols ferricyanide reduced/hour*coleoptile segment and an apparent Km (ferri) of 2.25mM.
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…
STUDY ON CONVERSION OF ENCAPSULATED VITRO-DERIVED PROPAGULES OF 'C35' CITRANGE [C. SINENSIS (L.) OSB. × P. TRIFOLIATE (L.) RAF.]
2015
Fight against Citrus tristeza virus (CTV) implies the use of CTV-resistant rootstocks, such as citranges [C. Sinensis (L.) Osb. × P. Trifoliata (L.) Raf.]. The 'C35' represents a promising tolerant to CTV genotype. The employment of innovative in vitro techniques, such as encapsulation, could open new perspectives for this genotype propagation, particularly in the nursery activity. Preliminary experiments on calcium-alginate encapsulation of microcuttings (unipolar propagules) have already been performed to evaluate the use of tissue culture for the propagation and the preservation of different citrange rootstocks: Carrizo and Troyer. In the present study, the influence of different types a…