Como una estrategia de propagación y conservación, se obtuvieron embriones somáticos (ES) de Agave angustifolia Haw. a partir de ejes embrionarios cigóticos (EEC), cultivados en el medio de Murashige y Skoog (MS) a 25 % de su concentración, suplementado con vitaminas L2, 13.57 μmol de ácido 2,4-diclorofenoxiacético (2,4-D), 4.4 μmol de 6-bencilaminopurina (BAP) y 60 g L-1 de sacarosa. Para producir semillas sintéticas (SS), cada ES fue encapsulado en una matriz de alginato de sodio en complejo con cloruro de calcio. Se evaluaron tres concentraciones (3, 4 y 5 %) de la matriz de alginato de sodio (MAS) durante 15 y 30 min como tiempo de inmersión (TI) en cloruro de calcio, así como la concentración de las sales del medio MS (50 y 100 %) como endospermo sintético, enriquecido con 6-bencilaminopurina (BAP) (0.0, 4.4 y 8.8 μmol). También se evaluó el efecto de las tres concentraciones de la MAS en el porcentaje de germinación y de sobrevivencia de las SS. La germinación de las SS y sobrevivencia de las plántulas, 100 % en ambos casos, se observó en los ES encapsulados con 3 % de la MAS disuelta en medio MS a 100 % y suplementado con 4.4 μmol de BAP, con 15 o 30 min de TI en cloruro de calcio.

<p><strong>Background</strong>: Agaves in Mexico are plants with great economic, gastronomic and cultural value. Despite the multiple forms of reproduction of plants belonging to the genus <em>Agave</em>, several of these species are threatened due to their slow growth, low percentage of seed viability, destruction of its habitat, excessive looting, interruption of its ripening cycle due to the use of their different organs,however, it has been posible to establish biotechnological techniques for its propagation, conservation and genetic improvement. <strong>Objective</strong>: At the present work were selected a representative species  of Agave, one of them for pulque production (<em>A. salmiana</em>) (As) and the other one in the production of mezcal (<em>Agave marmorata</em>) (Am) with the aim to establish an efficient micropropagation protocol optimizing the concentrations of the citokinin benzylaminopurine (BA) and the auxin 2,4-Dichlorophenoxyacetic acid (2,4-D), on the <em>in vitro </em>morphogenesis of both species.<strong> Methodology: </strong>Two <em>in vitro </em>culture systems were conducted in three explants (zygotic embryonic axis (E1), <em>in vitro </em>meristematic zone (E2) and <em>ex vitro</em> meristematic zone (E3)). <strong>Results</strong>: Shoots regeneration was achieved in all tested experiments; the highest number of shoots in As was 23.8 for explant using the E2 of directly regenerated <em>in vitro</em> germinated plants using a concentration of 10 mg L^-1 of BA, while in Am 24.7 shoots/explant were obtained with 5 mg L^-1 of BA using the zygotic embryonic axis who throughing a callus phase. <strong>Implications</strong>: The results obtained help to understand the importance of developing specific micropropagation protocols for each species, as well as contribuiting in the masive multiplications of <em>A. salmiana</em> and <em>A. marmorata</em> by understanding the effect of cytokinin BA and auxin 2,4-D and their combination in the formation of shoots by direct and indirect organogenesis. This provides a conservation alternative and an opportunity to startgenetic improvment programs. <strong>Conclusion</strong>: The results of this research suggest that the choice of explant, multiplication system, species and plant growth regulators are the key to obtain a greater number of shoots with high <em>ex vitro</em> survival rates.</p>

<p><strong>Background</strong>: Nowadays, a growing demand for hybrids of <em>Phalaenopsis</em> sp. exists to satisfy this demand it is necessary to develop protocols for massive propagation that ensure high percentages of clonal regeneration, such as somatic embryogenesis. Besides, studying genetic variation within regenerated plants offers a greater understanding of the suitability of the micropropagation protocol in relation with genetic stability of the materials used. <strong>Objective</strong>: The present research work aimed to evaluate three concentrations of two types of plant growth regulators (RCV). 6-benzylaminopurine cytokinin (BA) (1.0, 2.0 y 3.0 mgL^-1) in combination with three concentrations of 2,4-diclorofenoxiacetic acid (2,4-D) (3.0, 4.0, 5.0 mgL^-1), for the induction of somatic embryos. In addition, the genetic stability of the regenerated plants was analyzed using molecular markers type RAPD (Random Amplified Polymorphic DNA). <strong>Methodology</strong>: The induction of somatic embryogenesis was induced from two leaf explants with different stages of develop from 15-20 cm in height <em>Phalaenopsis</em> sp. var. Dudú seedlings, cultivated <em>in vitro</em>; first leaf as mature explant (PH) and third leaf as young explant (TH). <strong>Results</strong>: The highest number of regenerated plants was 29.8 at 135 days after the start of the culture (ddic) with 2.0 and 5.0 mgL^-1 of BA and 2,4-D, respectively, using TH as explant. In the morphogenetic response of the regenerated explants, a correlation was observed between the age of the explant and the RCV concentration. Polymorphic bands were observed with the four primers used, indicating somaclonal variation in regenerated plants. <strong>Implications</strong>: The results obtained provide an alternative for regeneration, as well as offering a methodology to initiate genetic improvement programs in <em>Phalaenopsis</em> sp. var. Dudú. <strong>Conclusions</strong>: <em>In vitro</em> regeneration of <em>Phalaenopsis</em> sp. var. Dudú by somatic embryogenesis was achieved, as well as the analysis of the genetic integrity of the regenerated material.        </p>

<p><strong>Background:</strong> Somatic embryogenesis in <em>Agave angustifolia</em> is an option for massive <em>in vitro</em> propagation and genetic improvement of this species, this process involves the induction of embryogenic callus, the development and maturation of embryos and their germination to form a complete plant. In this sense, an optimized selection of the compounds of the culture medium is required. <strong>Objective:</strong> This study evaluated the effect of vitamin components (inositol, pyridoxine and thiamine) on callus formation and induction of somatic embryos in <em>A. angustifolia</em>. <strong>Methodology: </strong>Two consecutive assays were conducted, assay I consisted of eight treatments to determine the isolated effect and in combination of three vitamin compounds (250.0 mg of L^-1 inositol, 0.5 mg of L^-1 pyridoxine and 2.0 mg of L^-1 thiamine). In assay II the effect of six concentrations of thiamine (1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg L^-1) was determined. In both assays, a completely randomized experimental design was used and each treatment had 20 repetitions. <strong>Results:</strong> The results of assay I show that the formulation of the vitamin complex of the culture medium plays a fundamental role in this process, suggesting that thiamine is an essential compound for the induction of somatic embryos (SE) of <em>A. angustifolia</em> because calluses obtained in thiamine supplemented media (alone or in combination) had a better embryogenic response than those not supplemented with this compound; In addition, in assay II with the increase in the concentration of thiamine to 2.5 and 3.0 mg L^-1 in the culture medium, it is possible to induce a higher number of SE per explant (50.5 and 55.9, respectively), compared to 35.8 SE induced with the original concentration of thiamine (2.0 mg L^-1). <strong>Implications: </strong>The results of this study contribute to a better understanding of the importance of the formulation of the vitamin complex and the effect of its addition in the culture medium to induce a greater number of SE in <em>A. angustifolia</em>. This can help in the beginning of programs of genetic improvement and <em>ex situ</em> conservation of this species. <strong>Conclusion:</strong> The results of this research suggest that thiamine is an essential compound for the acquisition of embryogenic potential in the somatic cells of <em>A. angustifolia</em>, since by increasing the concentration of this component in the culture medium it is possible to obtain a greater number of somatic embryos with high <em>ex vitro</em> survival rates.</p>