RESUMO

Pinus. ponderosa (P. Lawson and C. Lawson) is a commercial tree and one of the most important forest species in North America. Ponderosa pine suffers hardship when going through vegetative propagation and, in some cases, 15-30 years are needed to achieve full reproductive capacity. Based on previous works on P. ponderosa regeneration through in vitro organogenesis and trying to improve the published protocols, our objective was to analyze the influence of different types of explants, basal culture media, cytokinins, auxins, and light treatments on the success of shoot multiplication and rooting phases. Whole zygotic embryos and 44 µΜ 6-benzyladenine showed the best results in terms of explants survival. For shoot organogenesis, whole zygotic embryos and half LP (LP medium, Quoirin and Lepoivre, 1977, modified by Aitken-Christie et al., 1988) macronutrients were selected. A significant positive interaction between whole zygotic embryos and half LP macronutrients was found for the percentage of explants forming shoots. Regarding the light treatments applied, a significantly higher percentage of shoots elongated enough to be rooted was detected in shoots growing under blue LED at a light intensity of 61.09 µmol m-2 s-1. However, the acclimatization percentage was higher in shoots previously cultivated under fluorescent light at a light intensity of 61.71 µmol m-2 s-1. Anatomical studies using light microscopy and scanning electron microscopy showed the light treatments promoted differences in anatomical aspects in in vitro shoots; needles of plantlets exposed to red and blue LEDs revealed less stomata compared with needles from plantlets exposed to fluorescent light.

RESUMO

BACKGROUND Plant tissue culture involves the use of explants obtained from plants to induce organogenesis with the help of plant growth regulators (PGRs). Micropropagation techniques provide a faster and economical solution to the limitations associated with traditional methods of plant cultivation. The present study focuses on the multiple shoot induction and proliferation of Ficus carica var. Black Jack. Factors that influence the growth of in vitro multiple shoots on the apical buds, which include growth media and PGRs, were investigated in this study. Different concentrations of cytokinins like 6-benzylaminopurine (BAP), Thidiazuron (TDZ), and Kinetin (Kin) were used on woody plant medium (WPM) for the optimization of media for multiple shoot induction and proliferation. RESULTS Apical buds of Ficus carica var. Black Jack growing in WPM supplemented with BAP produced the healthiest plantlets, with the highest number of multiple shoots. The most efficient medium composition which produced the highest number of multiple shoots (37.8) per growing explant was WPM supplemented with 20 mM BAP. Proliferated multiple shoots were efficiently rooted using WPM + 20 mM BAP + 8 mM indole-3-acetic acid (IAA). This optimized medium composition significantly enhanced the production of multiple, disease-free plantlets using single apical bud explants of Ficus carica var. Black Jack. CONCLUSIONS In the present study the observations indicate that WPM supplemented with 20 mM BAP is the best-suited medium for organogenesis and multiple shoot culture of Ficus carica var. Black Jack, and this technique can be potentially applied for commercialization of the plant

Assuntos

RESUMO

Background The effect of polyamines (PAs) along with cytokinins (TDZ and BAP) and auxin (IBA) was induced by the multiple shoot regeneration from leaf explants of gherkin (Cucumis anguria L.). The polyphenolic content, antioxidant and antibacterial potential were studied from in vitro regenerated and in vivo plants. Results Murashige and Skoog (MS) medium supplemented with 3% sucrose containing a combination of 3.0 µM TDZ, 1.0 µM IBA and 75 µM spermidine induced maximum number of shoots (45 shoots per explant) was achieved. Regenerated shoots elongated in shoot elongation medium containing 1.5 µM GA3 and 50 µM spermine. The well-developed shoots were transferred to root induction medium containing 1.0 µM IBA and 50 µM putrescine. Rooted plants were hardened and successfully established in soil with a 95% survival rate. Twenty-five phenolic compounds were identified by ultra-performance liquid chromatography (UPLC) analysis The individual polyphenolic compounds, total phenolic and flavonoid contents, antioxidant and antibacterial potential were significantly higher with in vitro regenerated plants than in vivo plants. Conclusions Plant growth regulators (PGRs) and PAs had a significant effect on in vitro plant regeneration and also a biochemical accumulation of flavonols, hydroxybenzoic and hydroxycinnamic acid derivatives in C. anguria. Due to these metabolic variations, the antioxidant and antibacterial activities were increased with in vitro regenerated plants than in vivo plants. This is the first report describing the production of phenolic compounds and biological activities from in vitro and in vivo regenerated plants of C. anguria.

Assuntos

RESUMO

An efficient, highly reproducible protocol for multiple shoot induction and plant regeneration of Pongamia pinnata has been successfully developed using cotyledonary node explants. This study also demonstrates that preconditioning of explant stimulates production of multiple shoots from cotyledonary nodes of P. pinnata. The highest direct shoot regeneration (90 percent) with an average of 18.4 +/- 3.1 shoots/explant were obtained when cotyledonary node explants were excised from seedlings germinated on Murashige and Skoog (MS) media supplemented with benzyladenine (BA) 1 mg l-1, and subsequently cultured on MS media with 1 mgl-1 thidiazuron (TDZ). Scanning electron microscope observations of cotyledonary node (CN) explants excised from pre-conditioned and normal seedlings, revealed larger buds with rapid development in BA-preconditioned CN explants. The addition of adenine sulphate significantly increased the average number of shoots per explant. The highest direct shoot regeneration (93 percent) with an average of 32.2 +/- 0.93 shoots/explant was obtained from BA-preconditioned CN when cultured on MS media supplemented with 1 mg l-1 TDZ and 200 mg l-1 adenine sulphate (ADS). Repeated shoot proliferation was observed from BA preconditioned CN explants up to 3 cycles with an average of 15 shoots/explant/cycle when cultured on MS media supplemented with 1 mg l-1 TDZ and 150 mg l-1 L-glutamine, thus producing 45 shoots/CN explant. Shoots were elongated on hormone free MS media and rooted on 1/2 MS media supplemented with 1 mg l-1 of IBA. Rooted shoots were successfully acclimatized and established in soil with 80 percent success. The highly regenerative system developed in this investigation for this important tree could be a useful tool for genetic transformation.

Assuntos