Search results for "shoot"
showing 10 items of 298 documents
Micropropagation of Lavandula latifolia through nodal bud culture of mature plants
1996
Cultures of Lavandula latifolia Medicus were established from axillary buds of mature field-grown plants. Explants were initially cultured on media with two different macronutrient combinations and benzyladenine or kinetin added either individually or with naphthaleneacetic acid. Subsequently, explants were subcultured in Murashige and Skoog medium supplemented with 20% coconut milk, 0.57 μM indoleacetic acid and 8.88 μM benzyladenine. Shoot proliferation from axillary buds was not affected by seasonal fluctuations in the stock plants but depended on the macronutrient composition and on the type and concentration of cytokinin tested. Best results were obtained in explants initially cultured…
The source of gibberellins in the parthenocarpic development of ovaries on topped pea plants.
1988
The role and source of gibberellins (GAs) involved in the development of parthenocarpic fruits of Pisum sativum L. has been investigated. Gibberellins applied to the leaf adjacent to an emasculated ovary induced parthenocarpic fruit development on intact plants. The application of gibberellic acid (GA3) had to be done within 1 d of anthesis to be fully effective and the response was concentration-dependent. Gibberellin A1 and GA3 worked equally well and GA20 was less efficient. [(3)H]Gibberellin A1 applied to the leaf accumulated in the ovary and the accumulation was related to the growth response. These experiments show that GA applied to the leaf in high enough concentration is translocat…
Micropropagation of adultLavandula dentataplants
1998
SummaryA protocol for in vitro propagation of adult Lavandula dentata plants has been achieved. Cultures were established by placing nodal segments on Murashige and Skoog medium containing BA, KIN, and NAA. Highest shoot multiplication rates were obtained when explants grown in the presence of 5.0 μM BA or 20 (JLM KIN were transferred to medium with 8.8 μM BA and 15% coconut milk. Multiplication efficiency through subcultures was significantly affected by the cytokinin concentration in the initial culture medium. Subculture reduced drastically the final number of shoots produced on nodal segments isolated from shoots grown in the presence of 2.0 μM BA or 40.0 μM KIN. Shoots were easily root…
Transport and partitioning of 13C-photoassimilate between peach fruiting shoots
2008
We used a non-intrusive method (13CO2 feeding) and a manipulative approach to see whether fruiting shoots in peach trees are autonomous or may import carbon from neighboring shoots under forced conditions, and whether the degree of autonomy is influenced by the source-sink relationship on the shoot. In three experiments, leaf to fruit ratio (L:F) of selected fruiting shoots was moderately (2005 and 2006) or strongly (extreme enforcing 2006) altered to either encourage or discourage movement of carbon from 13C-labeled sending shoots (SFS) to receiving fruiting shoots (RFS), both located on the same main scaffold of V-shaped peach trees. At stage I and III of fruit growth, fruit and shoot tip…
Helical Shift Mechanics of Rubber V-Belt Variators
2011
A very common configuration of V-belt variators for motorcycles considers the correction of the belt tensioning depending on the resistant torque by means of suitable helical-shaped tracks allowing the driven half-pulleys to close/open. The theoretical model for belt-pulley coupling is rather complex for this configuration, where one half-pulley may run in advance and the other one behind with respect to the belt, and requires the repeated numerical solution of a strongly nonlinear differential system by a sort of shooting technique, until all the operating conditions are fulfilled (angular contact extent, torque, and axial force). After solving the full equations, the present study develop…
Growth stage and conditions affect sorbitol:sucrose ratio in peach source and sink organs
2008
Along with sucrose, sorbitol represents the major photosynthetic product and the main form of translocated carbon in peach. In leaves, the ability to synthesize and accumulate sorbitol and sucrose increases with leaf age or distance from the apex until full maturity. Also, in the internodes of a growing shoot sorbitol:sucrose ratio (SOR:SUC) increases with distance from the apex. In mature leaves, SOR:SUC increases in response to fruit sink removal and water deficit, due mainly to sorbitol rather than sucrose accumulation. Data from ‘Encore’ peach show that SOR:SUC remains fairly constant around 2:1 from the leaf blade all the way to the fruit peduncle and drops sharply in the fruit flesh a…
Factors controlling adventitious bud induction and plant regeneration in matureJuniperus oxycedrus leaves cultured in vitro
1994
The morphogenetic capacity of matureJuniperus oxycedrus L. leaves cultured in vitro has been studied, noting nutritive, hormonal, and environmental factors inducing differentiation and development of adventitious shoots. Bud primordia formed directly from the leaves. Highest bud differentiation rates were obtained when the explants were cultured for at least 21 days on a modified Schenk and Hildebrandt solidified medium containing 0.5 μM benzyladenine under a 16-h photoperiod. Maximum bud development and elongation was achieved on cytokinin-free medium containing 4% (wt/vol) sucrose and 0.05% (wt/vol) activated charcoal. Regenerated shoots were excised and induced to root on media with auxi…
Effect of growth regulators onin vitro propagation ofFicus benjamina cv. Exotica
1994
Stem internodes with axillary buds were excised from 5-year old trees ofFicus benjamina cv. Exotica. The effect of 6-benzylaminopurine (BAP), gibberellic acid (GA3), indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D) on shoot growth and proliferationin vitro was investigated. Multiple shoots were developed after 3–4 weeks from stem internodes with axillary buds incubated in Murashige and Skoog (MS) medium supplemented with phloroglucinol (PG) and BAP. Optimum shoot proliferation took place in the presence of 1.0 mg l−1 BAP. Shoots obtained could be elongated in a medium with 0.5 mg l−1 GA3 prior to their rooting. The root initiation was succ…
In vitro propagation ofSalix tarraconensis Pau ex Font Quer, an endemic and threatened plant
1996
Salix tarraconensis Pau ex Font Quer, an endemic willow species from northeast Spain, was micropropagated with nodal segments. Shoot multiplication was obtained with different cytokinins, either on Murashige and Skoog medium or woody plant medium. Best results for shoot formation were obtained on Murashige and Skoog medium containing 4.9 μM of 6-γ-γ-dimethylallylaminopurine. Shoots showed strong apical dominance, and some cultures displayed apical necrosis. Benzyladenine gave the worst results; shoots displayed very slow growth, deformed leaves, and hyperhydrity. Good rooting of shoots was obtained with different auxins or without plant growth regulators on woody plant medium. The best resu…
Occurrence and Heterogeneity of Chymotrypsin Inhibitors in Vegetative Tissues of Barley
1977
Inhibitors of chymotrypsin and the alkaline proteinase of Aspergillus oryzae were present in the shoots of barley seedlings and weak activities were also detected in the shoot tops of 6-week-old plants. Treatments which induce inhibitor formation in tomato and potato leaves had no effect when tested on mature leaves, seedlings, or young tillers of barley. Fractionation experiments with isoelectric focusing showed that the barley leaves contained several proteinase inhibitors acting on both chymotrypsin and the Aspergillus proteinase, and one inhibitor which acted only on the Aspergillus enzyme. All of these inhibitors were different from the five Aspergillus proteinase inhibitors which are …