Zeatin

About: Zeatin is a research topic. Over the lifetime, 2467 publications have been published within this topic receiving 64092 citations. The topic is also known as: Zeatin & (E/Z)-zeatin.

Effect of cytokinin type and concentration on in vitro shoot proliferation of hazelnut (Corylus avellana L.)

Abstract: Corylus avellana L. (hazelnut) is traditionally multiplied by layering because it is difficult to propagate vegetatively using shoot cuttings or grafting. Over the past two decades, in vitro micropropagation has become a successful technique for rapidly building large numbers of many new plant cultivars, but success with hazel remains mixed. The limiting factor for hazel has been low rates of in vitro shoot proliferation. Our study of hazel cultivar ‘Daviana’ examined the response of shoot multiplication to different cytokinin types and concentrations with the aim of maximizing new plant yields for commercial benefit. Four cytokinins (BAP, kinetin, zeatin, IPA) were evaluated at three concentrations. BAP at 5 mg/L (22.2 µM) was effective for initiation and elongation of new shoots when used with ‘Knoxfield2’ medium formulated for hazel. New shoot initiation was lowest when the medium contained kinetin.

Endogenous Phytohormones of Fern Polystichum aculeatum (L.) Roth Gametophytes at Different Stages of Morphogenesis in vitro Culture

Abstract: The content of indole-3-acetic (IAA), gibberellic (GA3), abscisic acids (ABA), and cytokinins—zeatin (Z), zeatin glucoside (ZG), zeatin riboside (ZP), isopentenyladenin (iР), and isopentenyladenosine (iРА)—was determined using the method of high-performance liquid chromatography in fern Polystichum aculeatum gametophytes at different stages of morphogenesis in vitro culture. It was shown that, at the stage of spatulate prothallium development, gametophytes contained significant amounts of GA3 and IAA, while the content of ABA and cytokinins was low. The inactive ZG and active iP were dominant. At the stage of cordiform thallus formation, the level of GA3 increased by 1.6, IAA by 2.4, and ABA by 1.7 times. The content of inactive iPA increased twice, significantly increased the level of active ZR and iP. At the development stage of sporophyte on the surface of gametophyte thallus, the levels of IAA, ABA, and GA3 decreased. The accumulation of inactive ZG and decrease in the content of active zeatin and zeatin riboside were documented. At all stages of gametophytes’ morphogenesis, GA3 was dominant, and its highest content was detected during the development of archegonia and antheridia. The pattern of gibberellic acid and zeatin riboside accumulation has shown the key role of these hormones in the regulation of growth processes and the development of reproductive structures of P. aculeatum gametophytes.

Regeneration of plants from leaf mesophyll protoplasts of the tetraploid potato cultivars Xenia and Bintje

Abstract: An improved method for the isolation of leaf mesophyll protoplasts ofSolanum tuberosum L. cvs. Xenia and Bintje, their culture and regeneration to plants is described. The improvements involve the culture of nodal stem explants on Schenk and Hildebrandt (SH) medium supplemented with AgNO3 (7.5 mg 11) and Alar 85 (5 mg 1−1), and the pre-treatment of donor plants for 2–3 weeks at a short photoperiod (6 h), a low irradiance (17 (μmol m−2s−1) and a low temperature (20 °C). Regeneration of cell wals was observed within 2–3 d and cell divisions within 7–12 d after resuspending freshly isolated protoplasts in Sidorov et al. (SW) medium. The resulting microcalli were cultured on solid media containing zeatin (1–2,5 mg 1−1) and/or NAA (0.1 and/or 0.01 mg 1−1) and subsequently on medium with BAR (0.25 mg1−1) and GA−3 (0.1 mg 11) for shoot regeneration.

Changes in levels of endogenous hormones in azalea released from apical dominance

Abstract: SummaryEnzyme-linked immunosorbent assays were used to quantify the levels of endogenous hormones in the 0.5 cm of shoot below the terminal bud (the shoot segment, where the lateral bud will emerge) of ‘Siji’ azalea (Rhododendron obtusum) when intact plants had been sprayed with 5% (w/v) Off-Shoot-O, a chemical pinching agent, or decapitated. The contents of indole-3-acetic acid, isopentenyladenine and isopentenyladenosine, zeatin and zeatin riboside, dihydrozeatin and dihydrozeatin riboside, gibberellins and abscisic acid were assayed. It was found that decapitation and Off-Shoot-O treatment could increase the concentrations of endogenous cytokinins and decrease the concentrations of indole-3-acetic acid in the shoot segment. On the other hand, both the Off-Shoot-O treatment and decapitation could elicit an increase in gibberellins concentrations and a decrease in abscisic acid concentration, suggesting that gibberellins and abscisic acid may be also involved in the growth of lateral buds.

In-vitro Production of Cabbage and Cauliflower

Abstract: Background: An efficient method of artificial mass propagation was optimized for two very nutritious vegetables of Pakistan, the cabbage and cauliflower. Being an agrarian economy, Pakistan’s more than half of the population depends directly or indirectly on agricultural products. Methodology: Hypocotyls of germinating of seeds (5-7 days old seedlings) were used as explants. Murashige and Skoog basal medium was supplemented with different concentrations of auxin (2,4 Dichlorophenoxy acetic acid) and cytokinin (benzyl amino purine) in combination to study the callus forming tendency of cabbage and cauliflower; and found better if used in ratio of 2:1 (at least) respectively. Results: For evaluation of regeneration potential Kinetin, Zeatin, Gibrellic acid-3, and Indole acetic acid were found good in combination with benzyl amino purine. Higher (than auxin) concentration of cytokinin was found essential to obtain good regeneration response of callus. Conclusion: Effectively concluded that these techniques can be used to raise the disease free stock of cabbage and cauliflower for genetic improvement of in-vitro bulk of varieties on commercial scale in a very brief time span.