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Tillandsia viridiflora (Beer) Baker is an epiphytic bromeliad endemic to Mexico, and the destruction of its habitat and illegal trade have led to its inclusion in the list of endangered species in NOM-059-SEMARNAT-2010. For its commercial use as an ornamental plant, a massive propagation system is required. In vitro plant tissue culture techniques are an option for producing large numbers of plants. The objectives of this study were to determine the optimal conditions to regenerate plants in vitro by direct organogenesis and acclimatize them. Organogenesis was evaluated in Murashige-Skoog (MS) medium with 6-benzylaminopurine (BAP, 0.0 and 8.8 µM) and naphthaleneacetic acid (NAA, 0.0 and 2.1 µM) from in vitro seedlings germinated in MS medium with 50% of the salt concentration. Shoot groups were placed in MS medium with gibberellic acid (GA3, 0 and 5.77 µM) to promote elongation. Shoot rooting was evaluated in MS medium with 50% of the salt concentration added with NAA (0.00 and 2.15 µM) and indole-3-butyric acid (IBA) (0.00 and 2.15 µM). During acclimatization, we evaluated two plant heights and two types of substrates: peat + perlite (1:1) and pine bark (Pinus). We established a completely randomized design and the data obtained were analyzed with ANOVA; the Tukey test was used for the comparison of means. Germination was 82% in five weeks. In the organogenesis, 10.4 shoots were induced per explant with 6.65 µM of BAP and 0.5 µM of NAA, and the multiplication resulted in 13 shoots with 4.4 µM of BAP and 0.5 µM of NAA, both cases in 12 weeks. The largest elongation (1.5 cm) of the shoots occurred by adding 5.7 µM of gibberellic acid; and the highest number of roots (2.4 roots per plant) resulted from adding 1.0 µM NAA. In acclimatization, survival was 100% with 4.5 and 6.5 cm plants planted in peat+perlite and pine bark [ABSTRACT FROM AUTHOR]

Chiltepin pepper (Capsicum annuum L. var. glabriusculum) is a spice collected from wild plants under anthropogenic pressure due to irrational extraction. The low germination of its seeds, the growing demand for fruit, and the agricultural practices could threaten this species in the short term. This study aimed to establish the optimal conditions for in vitro germination and organogenesis of chiltepin pepper. Using in vitro techniques, it is possible to increase the germination percentages and induce the morphogenesis from seedlings. The design of the experiments was completely randomized with 5 or 10 repetitions, and the experimental units were seeds and explants. Seeds were disinfected with 20% NaOCl (v/v) for 15 min. We evaluated the effects of the GA3 concentration on in vitro germination and shoot lengthening; we also studied combinations of BAP and IAA on shoot induction and multiplication, as well as concentrations of IBA on rooting. By immersing seeds in 5.7 mM GA3 for 30 min and cultivating them in MS medium with 50% salt concentration added with GA3, we achieved an in vitro germination of 90%. Shoots were generated from nodal segments of in vitro seedlings with 11.1 mM BAP and 2.8 mM IAA. Shoot multiplication was obtained with these same combinations of plant growth regulators. Shoot lengthening was favored in MS medium with 11.5 mM GA3, and rooting was induced with 10.0 and 12.5 mM IBA. Gibberellic acid improves chiltepin pepper seed germination, and organogenesis from nodal segments from in vitro germinated seedlings is possible. [ABSTRACT FROM AUTHOR]

Echinopsis chamaecereus cv. “Aurea” is an ornamental cactus whose achlorophyllic condition limits photosynthesis and it must be grafted onto another cactus in order to survive. For its commercial use, propagation systems such as in vitro plant tissue culture are required. The purpose of this research was to establish a protocol for in vitro regeneration of Echinopsis chamaecereus cv. ‘Aurea’ plants from areolar segments. Explants were disinfected with sodium hypochlorite (6% v/v) and colloidal silver (0.048%) and sown in MS medium with benzylaminopurine (4.4, 8.8 and 13.2 mM) and naphthaleneacetic acid (5.3, 10.7 and 16.0 mM). The experimental design was completely randomized with 20 repetitions per treatment and the experimental unit was an explant in each flask. Shoots and callus were formed at 30 d with 13.2 mM benzylaminopurine and 5.3 mM naphthalenacetic acid; 12.6 shoots per explant and 3.01 g of fresh callus tissue were obtained. In the multiplication stage 55 shoots were regenerated per explant with 13.2 mM benzylaminopurine and 5.3 mM naphthaleneacetic acid. Callus were not morphogenic and did not survive. With this in vitro regeneration system, it is feasible to generate “Aurea” plants for the production of micrografts and massive multiplication for conservation and commercial purpose. [ABSTRACT FROM AUTHOR]

Quercus sideroxyla is used to produce firewood, carbon and paper pulp. However, there are no management programs for replacing plants, so their conservation status is in danger in some areas of Mexico. The aim of this study was to develop an efficient methodology for in vitro propagation of Q. sideroxyla. Acorns in the fruiting season were harvested and then analyzed by X-ray. The embryos were induced to germination (stage 1), induction of adventitious shoots (stage 2) and rooting in culture media (stage 3). Four concentrations of Quoirin-Lepoivre medium (QL 10, 20, 30, 40%) were used with and without activated carbon (AC), as well as silver nanoparticles (AgNp) in stage 1. Whilst in stage 2 and stage 3, only the best resulting QL concentration was tested with three concentrations of 6-benzylaminopurine (BAP) and naphthalene acetic acid (NAA) as growth promotors. Experimental analysis in germination was carried out as a completely randomized block design, 16 treatments with five replicates and the Fisher test (p≤0.05) for means. Joint analysis of germination and shoots induction included a principal component analysis (PCA); induction and rooting of shoots were analyzed with the Wilcoxon paired analysis. The best results in the germination stage were observed in the treatment QL 30%, where 70% of germinated explants were obtained; but this treatment was not statistically different to the treatment QL 40%, which produced about 65% germination. In the remaining concentrations, explants oxidized completely; thus, a negative correlation medium-germination was observed. For multiple shoots induction stage, the best treatment was the lowest concentration of BAP:NAA which showed a positive behavior in the presence of activated carbon. Activated carbon on culture media, inhibited the oxidation of acorns and promoted the adventitious shoots and roots growth. This is the first report of the successful micropropagation of Q. sideroxyla. Using QL medium, activated carbon, silver nanoparticles and growth regulators promoted explant germination, rooting and vegetative development. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have various applications in plant biotechnology, mainly to eradicate microbial contamination and promote in vitro development. The aim of this study was to evaluate the effects of silver nanoparticles during micropropagation of vanilla (Vanilla planifolia) in a semi-solid medium. The morphology of nanoparticles was examined with a transmission electron microscope (TEM). For in vitro establishment, nodal segments of 2 cm in length were cultured on Murashige and Skoog (MS) semi-solid medium supplemented with 2 mg L-1 6-benzylaminopurine (BAP). AgNPs concentrations of 0, 25, 50, and 100 mg L-1 and 5, 10, and 20 min exposure times were evaluated during in vitro establishment. For multiplication, shoots of 2 cm in length were transferred to the same medium containing 0, 25, 50, and 100 mg L-1 concentrations of AgNPs. The characterization of AgNPs revealed a spherical shape with a form factor of 0.82, a roundness of 0.88, and average diameters of 35±15 nm. During in vitro establishment, the lowest total percent contamination (23.3, 21.6, and 16.6%) corresponded to explants exposed to 100 mg L-1 of silver nanoparticles for 5, 10, and 20 min, respectively. For shoot multiplication, the greatest lengths, number of shoots, and number of leaves were obtained from 25 mg L-1 and 50 mg L-1 of AgNPs. Treatments with AgNPs had no effect on shoot rooting or plantlet survival during acclimatization. These results suggest that the use of AgNPs can be an effective alternative for the reduction of contamination during in vitro establishment and the promotion of development during micropropagation of V. planifolia. [ABSTRACT FROM AUTHOR]

Chia (Salvia hispanica L.) is a crop with economic importance for its content of proteins and oils with nutritional value for human consumption. Techniques are required to obtain high quality seed from elite materials derived from genetic improvement. The objective of this research was to develop a system for in vitro regeneration by organogenesis of three varieties of S. hispanica. The experiments were established with single (germination and rooting) and factorial arrangement (shoot induction and multiplication) in completely random designs. Seeds were disinfected in sodium hypochlorite solution (15% v/v) +Tween®20 (0.5% v/v) for 20 minutes. Germination was achieved after 2 weeks in MS medium with 50% salt concentration. The organogenesis was initiated with the cultivation of apical buds, axillary buds and stem segments of seedlings germinated in vitro in MS medium with 50% of the concentration of salts and equimolar doses of kinetin and bencylaminopurine (BAP, 2.5-15 mM). Induction and multiplication of buds were obtained with 5 mM of kinetin at four weeks; 16.3, 14.9 and 10.5 buds were induced per explant of the "Blanca 54", "Negra 59" and "Pinta" varieties. In the multiplication, 28.6, 28.5 and 23.3 buds were formed in "Pinta", "Blanca 54" and "Negra 59", respectively. The rooting of 2.5 cm long buds was effective in MS medium with 50% salt concentration and 0.57 µM indoleacetic acid (AIA) after two weeks. The acclimatization of seedlings was 70% in "Negra 59" and "Blanca 54" varieties and 80% in "Pinta" in a mixture of peat and perlite (1:1) fertilized with 50 % Steiner solution. [ABSTRACT FROM AUTHOR]

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Apuleia leiocarpa is an endangered tree species with high quality timber. Propagation by seed is difficult due to irregular fruiting and water-impermeable tegument, so asexual propagation is a promising alternative. This study aimed to evaluate in vitro and ex vitro rooting of A. leiocarpa and acclimatization of micropropagated plantlets. The hypothesis was that type of explant, indolebutyric acid (IBA) concentration and substrate influence the induction of adventitious roots in apuleia. For in vitro rooting, nodal segments and micro-cuttings were grown in Wood Plant Medium (WPM) with 0, 4.9, 9.8, 14.7 and 19.6 μM IBA. Compositions of commercial substrate + vermiculite + coarse sand and commercial substrate + vermiculite, in equal proportions, were tested for acclimatization. For ex vitro rooting, nodal segments and micro-cuttings were treated with 0 and 4920 μM IBA for 10 s and grown in equal proportions of: commercial substrate + vermiculite + coarse sand, commercial substrate + vermiculite, and commercial substrate + coarse sand. Nodal segments presented greater rooting in vitro than micro-cuttings without need for IBA supplementation in the culture medium. Substrate composition did not affect survival or growth of in vitro rooted plantlets during acclimatization. The best ex vitro rooting was found in nodal segments and explants treated with 4920 μM IBA and grown in commercial substrate + vermiculite + coarse sand. Ex vitro rooting is a promising technique for producing apuleia plantlets; however, adjustments to environmental conditions in both ex vitro rooting and acclimatization are necessary in order to maximize survival of micropropagated A. leiocarpa plantlets. [ABSTRACT FROM AUTHOR]

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)