Formación de callos con estructuras embriogénicas en Dioscorea rotundata Poir cv. `Blanco de Guinea'

Yam contributes to energy and nutritional requirements of most of the population of developing countries. However, their extensive culture is constrained by the limited availability of planting material with physiological and sanitary quality, and also part of the harvesting is used as seed in the next planting. For this reason, it is necessary to establish a methodology for plant regeneration and somatic embryogenesis could facilitate their micropropagation and genetic improvement. This study aimed to form embryogenic callus in Dioscorea rotundata Poir cv. `White Guinea'. The effect of the addition of 2,4-dichlorophenoxyacetic acid (2,4-D) (0, 1.0, 2.0 and 4.0 mg l-1) was determined, in combination with three types of explants from in vitro plants (leaves petiole, petiole segments and root sections). The highest percentage of embryogenic callus was obtained with 1.0 mg l-1 2,4-D and leaves with petiole as explants. These were characterized by the presence of compact whitish nodules. Key words: 2,4-dichlorophenoxyacetic acid, somatic embryogenesis, micropropagation, yamEl ñame contribuye a los requerimientos energéticos y nutricionales de gran parte de la población de los países en cultivo, sin embargo, su desarrollo extensivo se ve limitado por la poca disponibilidad de material de plantación con calidad fisiológica y sanitaria, y además, parte de la cosecha es utilizada como semilla en la próxima plantación. Por tal razón, es necesario establecer una metodología eficiente de regeneración de plantas como la embriogénesis somática que facilite su micropropagación y el mejoramiento genético del cultivo. El presente trabajo tuvo como objetivo formar callos con estructuras embriogénicas en Dioscorea rotundata Poir cv. `Blanco de Guinea'. Se determinó el efecto de la adición de ácido 2,4-diclorofenoxiacético (2,4-D) (0, 1.0, 2.0 y 4.0 mg l-1), en combinación con tres tipos de explantes procedentes de plantas in vitro (hojas con pecíolo, segmentos de pecíolos y secciones de raíz). El mayor porcentaje de callos con estructuras embriogénicas se obtuvo con 1.0 mg l-1 de 2,4-D y hojas con pecíolo como explante. Estos se caracterizaron por la presencia de nódulos compactos de coloración blanquecina.  Palabras clave: ácido 2,4-diclorofenoxiacético, embriogénesis somática, micropropagación, ñam

Multiplicación, histodiferenciación y regeneración de suspensiones celulares embriogénicas en plátanos vianda “Navolean” (AAB)

The results obtained show that the best cell density for the multiplication of the cell suspensions in the cultivar ‘Navolean’ is 3.0% settled cell volume. In the histo-differentiation phase the greatest formation of somatic embryos in the globular stage was obtained using a density of 12.0% final cell volume in liquid culture medium. The maturation of the embryos and an increase in germination was possible on using 0.5 gFW of somatic embryos during 30 days in the maturation culture medium. Using temporary immersion systems with 0.5 gFW of mature somatic embryos, the germination value was increased to 77.40%Key words: Musa, settled cell volume (SCV), somatic embryogenesis, temporary immersionEl mejor resultado para la multiplicación de las suspensiones celulares embriogénicas en el cv. ‘Navolean’ se obtuvo al utilizar una densidad celular del 3.0% del Volumen de Células Sedimentadas. En la etapa de histodiferenciación se logró la mayor formación de embriones somáticos en etapa globular utilizando como densidad 12.0% de volumen final de células en medio de cultivo líquido. Al emplear 0.5 gMF de embriones somáticos durante 30 días de cultivo en el medio de cultivo de maduración, fue posible lograr la maduración de los embriones e incrementar la germinación. Empleando sistemas de inmersión temporal con 0.5 gMF de embriones somáticos maduros se incrementó el valor de germinación a 77.40%.Palabras clave: embriogénesis somática, inmersión temporal, Musa, volumen de células sedimentadas (VCS

Embriogénesis somática en el cv. Navolean a partir de ápices de brotes de yemas axilares

In order to develop embryogenic cultures in AAB Musa genotypes without persistent male inflorescence, the process has had greater success from proliferating meristems for callus formation with embryogenic structures. Based on the previous information, other alternative explant sources for somatic embryogenesis development in cv. Navolean. Meristematic apexes were cultured in p5 culture medium supplemented with thidiazuron and ancymidol (0.2, 0.4, 0.6, mg.l-1) to obtain axillary buds. Later, axillary buds and proliferated meristems were tested for callus induction with embryogenic structures combinations with different 2,4-D concentrations. The best growth regulator for obtaining axillary buds was ancymidol (0.2 mg.l-1). For callus formation with embryogenic structures, axillary buds at 1.0 mg.l-1 2,4-D provided a higher percentage (13.6%). These results permitted the development of embryogenic cell suspensions from somatic embryos.Key words: Ancymidol, embryogenic cell suspension, plantainEl desarrollo de cultivos embriogénicos en los genotipos AAB de Musa, que no poseen inflorescencia masculina persistente, ha tenido mayor éxito a partir de multiyemas para la formación de los callos con estructuras embriogénicas pero esto pudiera incrementar la variación somaclonal. Teniendo en cuenta lo anterior se trabajó en la determinación de otra fuente de explante inicial alternativa para el desarrollo de la embriogénesis somática en el cultivar objeto de estudio. Se cultivaron brotes axilares en el medio de cultivo P5 suplementado con tidiazuron y ancimidol (0.2; 0.4; 0.6 mg.l-1 cada uno por separado) para lograr la brotación de yemas axilares. Posteriormente para formar los callos con estructuras embriogénicas se colocaron los ápices de brotes obtenidos de yemas axilares en un medio de cultivo ZZ con diferentes concentraciones de 2,4-D. El mejor regulador del crecimiento para la brotación de yemas axilares fue el ancimidol (0.2 mg.l-1). Para la formación de callos con estructuras embriogénicas, la concentración de 1.0 mg.l-1 de 2,4-D propiciaron el mayor porcentaje (13.6%). A partir de los embriones somáticos producidos se logró el establecimiento de suspensiones celulares embriogénicas. Se demostró que es posible el desarrollo de la embriogénesis somática en el cv. Navolean no solo a partir de scalps de multiyemas.Palabras clave: ancimidol, plátanos, suspensiones celulares embriogénica

Evaluación en campo de plantas regeneradas por embriogénesis somática a partir de ápices de brotes de yemas axilares en cv. ‘Navolean’ (Musa spp., AAB)

The use of shoots apexes from axilary buds for callus induction with embryogenic structures in plantain ‘Navolean’ (Group AAB) permitted to develop a plant regeneration method through out somatic embryogenesis. In order to know the phenotypic variants that may be produced with the previously mentioned method , 1000 plants were planted in field conditions in comparison to those coming from somatic embryos obtained from multibuds as initial explants and organogenesis-derived plants (shoot tips)and conventionally derived plants (corms), during two growing cycles. The main morphological characters and yield components were evaluated. The total frequency of somaclonal variation during the first growing cycle in plants coming from somatic embryos obtained from shoots apexes from axilary buds as initial explants were 1.1%, and 8,6% in regenerated plants from somatic embryos obtained from multi-buds as initial explants. Later, in this same growing cycle, plants regenerated from somatic embryos (both sources) showed a similar performance between them and they were significantly superior in all evaluated variants in comparison to corm-derived plants. In the second growing cycle, significant differences were not observed in yield components of suckers from evaluated plants, in spite of the propagation method used. With regard to somaclonal variation, the best performance was obtained with shoots apexes from axilary buds as explants. Finally, the feasibility of using the new method was shown.Key words: embryogenic cell suspensions, somaclonal variationEl uso de ápices de brotes de yemas axilares para la inducción de callos con estructuras embriogénicas en el cultivar de plátano vianda ‘Navolean’ (Grupo AAB), posibilitó el desarrollo de una metodología de regeneración de plantas por embriogénesis somática en el cultivar objeto de estudio. Con el objetivo de conocer la variabilidad fenotípica que se podría producir mediante la misma, se plantaron en el campo 1 000 plantas que se compararon durante dos ciclos de cultivo con otras procedentes de embriones somáticos obtenidos de scalps de multiyemas como explante inicial, con plantas obtenidas por organogénesis (ápices meristemáticos) y mediante la propagación convencional (cormos). Para ello se evaluaron los principales caracteres morfológicos de la planta y componentes del rendimiento.La frecuencia total de variación somaclonal durante el primer ciclo de cultivo en las plantas procedentes de embriones somáticos donde el explante inicial habían sido ápices de brotes de yemas axilares fue de 1.1% y de 8.6% en las plantas regeneradas de embriones somáticos scalps de multiyemas. Luego en este mismo ciclo de cultivo las plantas regeneradas de embriones somáticos (ambas procedencias) mostraron un comportamiento similar entre ellas y en todas las variables evaluadas fueron superiores en relación con las plantas procedentes de cormos con diferencias significativas. En el segundo ciclo de cultivo, al evaluar los hijos, de las plantas estudiadas no se observaron diferencias significativas en los componentes del rendimiento, independientemente del método de propagación utilizado. Referente a la variación somaclonal, se obtuvo el menor índice en las plantas obtenidas por embriogénesis a partir de ápices de yemas axilares. Finalmente se demostró la factibilidad de utilizar la nueva metodología desarrollada.Palabras clave: suspensiones celulares embriogénicas, variación somaclona

Obtaining of somatic embryo and establishment of embryogenic cell suspension in Plantain cv ‘Navolean’ (AAB)

Cells suspension of plantains and bananas with promising results have been reported internationally, however, in Cuba it is not at so for AAB group. So, the following working objectives have to be considered: in vitro multiplication of the material used as explant source. For in vitro multiplication of the material used as explant source. For in vitro multiplication of the material, several 6-BAP and IAA concentration were studied. Induction of embryogenic cultures was the developed form “scalps” incubated in solid medium ZZ. Suspensions were established in 10 ml and 25 ml Erlenmeyers containing liquid medium ZZ. The best medium for explant multiplication was MS (salts and vitamins), additional thiamin (1 mg.l-1), sucrose (40 g.l-1); 4.50 mg.l-1 6-BAP, 0.88mg.l-1 IAA and solidified agar (6.0 g.l-1) (medium 7). A 4.66% callus formation with embryogenic cultures was obtained, and cell suspensions were established 20 days after incubation in 10 ml Erlenmeyers. Media were changed every third day. Key Words: somatic embryogenesis, plantain, scalp

Embryogenic callus formation in <i>Dioscorea rotundata</i> Poir cv. `Blanco de Guinea'

Yam contributes to energy and nutritional requirements of most of the population of developing countries. However, their extensive culture is constrained by the limited availability of planting material with physiological and sanitary quality, and also part of the harvesting is used as seed in the next planting. For this reason, it is necessary to establish a methodology for plant regeneration and somatic embryogenesis could facilitate their micropropagation and genetic improvement. This study aimed to form embryogenic callus in Dioscorea rotundata Poir cv. `White Guinea'. The effect of the addition of 2,4-dichlorophenoxyacetic acid (2,4-D) (0, 1.0, 2.0 and 4.0 mg l-1) was determined, in combination with three types of explants from in vitro plants (leaves petiole, petiole segments and root sections). The highest percentage of embryogenic callus was obtained with 1.0 mg l-1 2,4-D and leaves with petiole as explants. These were characterized by the presence of compact whitish nodules. Key words: 2,4-dichlorophenoxyacetic acid, somatic embryogenesis, micropropagation, ya

Somatic embryogenesis in plantain cultivar 'FHIA - 25' (AAB) from meristem tips

Plantain cultivar 'FHIA – 25' (AAB) shows high yielding qualities and high resistance to Black Sigatoka disease, but its sugar content in the fruit is low, so a regeneration method at cell level is necessary, such as somatic embryogenesis supported by biotechnological tools to improve fruit quality. This work was performed with the aim of establishing a plant regeneration method via somatic embryogenesis using initial explants of shoot apices from axillary buds in liquid culture medium. Homogenous embryogenic cell suspensions were obtained from mentioned explants. The highest cellular multiplication rates were achieved at 3,0% density. The incubation of somatic embryos during 30 days in the maturation culture medium permitted to increase germination. During the acclimatization stage, plants regenerated from somatic embryos, as well as plants from organogenesis, showed a high survival percentage (98 and 97 respectively), without somaclonal variation