Comportamiento del Virus del Estriado del Banano en plantas propagadas in vitro de los cultivares de Musa híbridos FHIA 20 y FHIA 21

The losses taken place by the black and yellow Sigatoka have impelled the introduction to the country of the tetraploid hybrids from FHIA, however, at the present time, the high incidence of Banana Streak Virus in these hybrids is well known. To evaluate the effect of the micropropagatión process, on the fluctuations of the viral concentration in the tissue, they were introduced to the in vitro propagation positive and negative plants serologically tested of the cultivars FHIA 20 and 21, previously indexed in field (DAS-ELISA), later on they passed to phase of adaptation to evaluate the derived results of the diagnosis tests carried out after 3-6 months of transplanted. As a result of the DAS-ELISA carried out to the plants in phase of adaptation (37) 22.2 % of the negative plants, indexed in field, was positive, while 68.4 % of the positive plants, indexed in field, was negative, in both cases all the plants were positive to the diagnosis for PCR. In some cases, given the implication of the obtained results, was used the ISEM as technique of diagnostic, for the corroboration of the same ones.Key Words: badnavirus, diagnostic, in vitro culture, MusaLas pérdidas producidas por la Sigatoka negra y la Sigatoka amarilla han impulsado la introducción en Cuba de los híbridos de bananos y plátanos obtenidos por la Fundación Hondureña de Investigaciones Agrícolas que muestran resistencia parcial frente a esta enfermedad. Sin embargo, es bien conocida la alta incidencia del Virus del Estriado del Banano en dichos cultivares. Para evaluar el efecto del proceso de micropropagación, sobre las fluctuaciones de la concentración viral en el tejido, se introdujeron al cultivo in vitro plantas serológicamente positivas y negativas de los cultivares FHIA 20 y FHIA 21, previamente indexadas en campo (ELISA-DAS), posteriormente pasaron a fase de aclimatización para evaluar los resultados derivados de las pruebas de diagnóstico realizadas después de 3-6 meses de aclimatizadas. Como resultado del ELISA-DAS realizado a las plantas en fase de aclimatización (37) el 22.2 % de las plantas negativas, indexadas en campo, resultaron positivas, mientras que el 68.4 % de las plantas positivas, indexadas en campo, resultaron negativas, en ambos casos todas las plantas resultaron positivas al diagnóstico por la reacción en cadena de la polimerasa. En varias líneas con diagnóstico positivo se empleó la inmuno-microscopía electrónica como técnica de corroboración de los diagnósticos realizados.Palabras clave: badnavirus, cultivo in vitro, diagnóstico, Mus

Enraizamiento y aclimatización de plantas transgénicas de papaya var. Maradol roja

The disease caused by Papaya ringspot virus is the most important in papaya worldwide. The use of biotechnological techniques, as auxiliary tools, has facilitated the genetic improvement in papaya. Nevertheless, this species has a lot of constraints, mainly during rooting and acclimatization phases. For that reason we developed the present work. The in vitro and ex vitro rooting was evaluated. Culture media with different concentrations of indol-3-butiric acid hormone were used in the in vitro rooting. The influence of Trichoderma harzianum bioproduct in the acclimatization of plants was also studied. The in vitro rooting of transgenic plants was achieved by applying 2 mg.l-1 of indol-3-butiric acid in the culture medium. The ex vitro rooting with high percentages of plants survival was also obtained. The applications of T. harzianum bioproduct on the substrate, previous to the plantation, demonstrated its stimulating effect.Key words: Carica papaya, ex vitro, in vitro, Trichoderma harzianumLa enfermedad causada por el Virus de la mancha anular de la papaya es la más importante del cultivo de la papaya en el mundo. El empleo de las técnicas biotecnológicas, como herramienta auxiliar, ha contribuido al mejoramiento genético en este cultivo, aunque tiene dificultades durante las fases de enraizamiento y aclimatización. Tomando como base estas problemáticas se desarrolló el presente trabajo con el objetivo de lograr el enraizamiento y aclimatización de líneas transformadas de papaya. Se determinó la influencia de dos medios de cultivo con diferentes concentraciones de ácido indol-3-butírico (AIB) sobre el enraizamiento in vitro y ex vitro de plantas de papaya transformadas. Además, se valoró la influencia de la aplicación del biopreparado de Trichoderma harzianum en su aclimatización. Se logró el enraizamiento in vitro de plantas de papaya transgénicas al utilizar 2 mg.l-1 de ácido indol-3-butírico en el medio de cultivo, así como el enraizamiento ex vitro con altos porcentajes de supervivencia. Se demostró la factibilidad de la aplicación del biopreparado de T. harzianum al sustrato, previo a la plantación, por su efecto estimulante.Palabras clave: Carica papaya, ex vitro, in vitro, Trichoderma harzianu

Obtention of papaya var. Maradol Roja transgenic plants with delay in the fruits ripening

Papaya is a crop of economic importance for tropical countries. However, post-harvesting losses of Maradol Roja cultivar, the most important in Central America, have been up to 80%, due to a lack of proper infrastructure and qualified personnel at the rural areas and mainly because of the quick ripening of the fruits. The ripening process in climacteric fruits like papaya is regulated by ethylene levels. By reducing the genetic expression of the key enzymes which participate in the biosynthesis of this phytohormone, a decrease of the expression could be obtained. With the purpose of obtaining transgenic plants with delayed fruit ripening, accox1 gene encoding for the 1-aminoiciclopropeno-1-carboxylate (ACC) oxidase of the Maradol Roja variety was isolated and a binary vector for gene gun mediated transformation constructed with this gene in antisense orientation. In vitro transgenic lines, verified by PCR, were obtained. Key words: antisense technology, Carica papaya, ethylene, ripenin

Behavior of occurrence of Banana Streak virus in in vitro propagated plants from cultivars of Musa hybrids FHIA-20 and FHIA-21

The losses taken place by the black and yellow Sigatoka have impelled the introduction to the country of the tetraploid hybrids from FHIA, however, at the present time, the high incidence of Banana Streak Virus in these hybrids is well known. To evaluate the effect of the micropropagatión process, on the fluctuations of the viral concentration in the tissue, they were introduced to the in vitro propagation positive and negative plants serologically tested of the cultivars FHIA 20 and 21, previously indexed in field (DAS-ELISA), later on they passed to phase of adaptation to evaluate the derived results of the diagnosis tests carried out after 3-6 months of transplanted. As a result of the DAS-ELISA carried out to the plants in phase of adaptation (37) 22.2 % of the negative plants, indexed in field, was positive, while 68.4 % of the positive plants, indexed in field, was negative, in both cases all the plants were positive to the diagnosis for PCR. In some cases, given the implication of the obtained results, was used the ISEM as technique of diagnostic, for the corroboration of the same ones. Key Words: badnavirus, diagnostic, in vitro culture, Mus