Greatest Number Of Shoots Research Articles

In vitro shoot regeneration of Populus deltoides: effect of cytokinin and genotype

Treatment differences were observed in the in vitro adventitious shoot regeneration response from internodal explants of three genotypes of Populus deltoides cultured on media supplemented with five concentrations each of the cytokinins 6-benzyladenine, 2-isopentyladenine, and zeatin. For each of the three genotypes, the greatest number of shoots were consistently regenerated on media containing the cytokinin zeatin. Tissue necrosis resulted when explants from any of the three genotypes were cultured on media supplemented with 6-benzyladenine. A zeatin concentration by genotype interaction was also observed. Genotypic differences in shoot regeneration were observed for 16 genotypes of Populus deltoides when cultured on medium supplemented with 0.5 mgL(-1) zeatin. Six genotypes were highly recalcitrant and failed to regenerate shoots. The percent of explants regenerating was greater than 50% for four genotypes.

In Vitro Propagation of Oxydendrum arboreum from Mature Trees

Abstract Shoots forced from dormant stems and nodal explants from current season’s growth of a 24-year-old sourwood [Oxydendrum arboreum (L.) DC] were cultured on Woody Plant Medium (WPM) supplemented with zeatin. The greatest number of shoots >10 mm was produced with 4 μM zeatin, whereas BA and 2iP were ineffective at the same concentrations. Addition of IAA (5 and 10 μM) to the medium reduced the number of shoots. Thidiazuron (0.0045–0.045 μM) produced a few short shoots. In vitro rooting of the proliferated shoots was enhanced with 2.5 to 10 μM of IBA in the culture medium. Chemical names used: N-(phenylmethyl)-lH-purin-6-amine (BA); 1H-indole-3-acetic acid (IAA); 1H-indole-3-butyric acid (IBA); N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP); 1-naphthaleneacetic acid (NAA); 2-methyl-4-(1H-purin-6-ylamino)-2-niten-1-ol (zeatin); N-phenyl-N’-1,2,3-thiadiazol-5-ylurea (thidiazuron, TDZ).

Micropropagation of Flame Azalea

Shoots tips excised from an actively growing stock plant of flame azalea [Rhododendron calendulaceum (Michx.) Torr.] were surface sterilized, the terminal portions were removed (decapitated) and the shoots placed horizontally on agar-solidified Woody Plant Medium (WPM) supplemented with 15 ppm 6-(γ, γ-dimethylallylamino)-purine (2iP). Within 4 to 6 months multiple shoot formation commenced. After 2 to 3 additional months of growth, axillary shoots were excised from the original explants. The shoots were decapitated and placed on WPM. After 2 subcultures, 8-node axillary shoots were excised, decapitated and cultured on agar-solidified WPM supplemented with 0, 4, 8, 12, 16, 24, and 32 ppm 2iP. The greatest number of shoots (microcuttings) ≥ 5 mm (0.2 in) were produced at 12 ppm 2iP. Microcuttings ≥ 10 mm (0.4 in) were rooted using ex vitro procedures. Enhancement of both axillary shoot multiplication and shoot length was achieved by addition to the medium of 80 ppm adenine sulfate and 200 ppm NaH2PO4.

Micropropagation of kiwifruit using non-axenic shoot tips

Kiwifruit (Actinidia chinensis Planch.) shoot tips were subjected to a standard surface sterilization procedure and cultured on a Murashige and Skoog basal medium in the presence of two surviving bacterial contaminants. The fresh weight increase of the cultures and the number of shoots produced were greater in liquid medium than in medium solidified with 0.4 or 0.8% agar. A greater number of shoots was obtained with 125 ml than with 50, 250, or 500 ml Erlenmeyer flasks. A concentration of 2 mgl-1 N6-benzylaminopurine (BAP) gave a greater increase in fresh weight than either 0 or 4 mgl-1.

Explant origin as a determinant ofin vitroshoot proliferation inPrunusandSpiraea

SummaryShoot explants of Prunus cerasifera cv Thundercloud and Spiraea × bumalda cv Froebelii were cultured on Linsmaier and Skoog (1965) medium with the addition of benzy- ladenine. Explant length, axillary bud number, presence or absence of the shoot apex and derivation of the explant were varied. Shoot proliferation was enhanced by reduction of axillary bud number, and at low BA concentrations by removal of the meristem tip. Large explants (10–20 mm) produced a greater number of shoots than small explants (5–10 mm), and shoot proliferation was greatest in explants derived from the top of the canopy of the parent plant. These results suggest that explant variability due to origin may account for the differences in morphogenic response frequently observed during micropropagation.

Axillary and Adventitious Shoot Proliferation of Exbury Azaleas in Vitro.1

Abstract Shoot tips of Exbury azalea (Rhododendron sp.) were proliferated on Anderson's Rhododendron medium supplemented with 6-benzylamino purine (BA), 6-(= ϒ, = ϒ-dimethylallylamino) purine (2iP), 6-(= ϒ, = ϒ dimethylallylamino) purine riboside (2iP-riboside), 6-furfurylaminopurine (kinetin), or 6-(4-hydroxy-3-methylbut-2-enylamino) purine (zeatin). The greatest number of shoots was produced on medium containing zeatin, a lesser number on 2iP and 2iP-riboside, and the least on BA and kinetin. Shoot proliferation was affected by genotype. Few adventitious shoots formed on detached cultured leaves. Shoot tips rooted when subcultured on medium without cytokinin or when inserted in moist milled sphagnum.

A study on the population dynamics of the perennial plant species Chamaenerion angustifolium (L.) scop.

From a study of differently aged populations of the perennial plant species Chamaenerion angustifolium a concept was deduced concerning the population dynamics of the species. The age structure was determined by counting the rings of periderm in the roots. After the establishment of seedlings vegetative propagation is the main factor in population development. The longevity of populations depends on exogenic factors, since older root samples-if isolated from the population-appeared to be as viable as were younger specimens. The oldest population studied had been able to persist for about thirty years due to the mineral cycle brought about by the population itself. In still developing populations a greater number of shoots tend to sprout from younger roots than from older roots, when compared per unit root weight. The shoot density in full-grown populations (in which further root expansion does not occur) is related to the root biomass per unit area. It was suggested that the allocation of reserve assimilates within the roots is an endogenic factor determining the shoot density. After the early sprouting phase the shoot development depends mainly on environmental factors.

Effect of Time of Rhizomatous Propagation of a Temperate Zone Bamboo on Shoot Growth1

AbstractAn experiment was designed to evaluate the influence of time of rhizomatous propagation of a temperate zone bamboo, Phyllostachys viridis, on shoot growth. Propagules (rhizomes) were dug at random from the field at approximately monthly intervals from September 30, 1960 to September 5, 1961. Three nodal sections of the propagules were planted in the greenhouse and evaluated 6 weeks later for the percent of nodal buds producing shoots and for the resultant shoot growth.There was no significant difference in mean shoot growth from rhizomes propagated during September, November, or December. December propagation favored smaller, but a greater number of shoots. Fifty percent greater shoot growth was realized from the propagation on February 21, 1961 than any earlier or later planting due to both the number of shoots produced and their average height per node.