| dc.description.abstract | La mutagénesis in vitro es una alternativa para generar variación genética en vainilla (Vanilla planifolia Jacks. ex Andrews) debido a su baja diversidad genética. El objetivo de este estudio fue inducir variación somaclonal en V. planifolia mediante radiación gamma y su detección mediante marcadores moleculares ISSR (Inter Simple Sequence Repeats). Brotes previamente establecidos in vitro fueron multiplicados en medio de cultivo Murashige y Skoog suplementado con 2 mg L-1 BAP (6-Bencilaminopurina). Se irradiaron explantes con diferentes dosis (0, 20, 40, 60, 80 y 100 Gy) de rayos gamma 60Co. A los 60 d de cultivo, se evaluó la sobrevivencia, número de brotes por explante, longitud de brote y número de hojas por brote. Para el análisis molecular, se utilizaron diez brotes para cada dosis y la planta donante como testigo. Se utilizaron ocho cebadores y se obtuvieron un total de 43 bandas. Se calculó el porcentaje de polimorfismo (%P) y se obtuvo un dendrograma basado en la distancia genética de Jaccard y el método de agrupación neighbor joining. Los resultados mostraron un efecto hormético sobre los explantes, promoviendo el desarrollo a bajas dosis (20 y 40 Gy) e inhibición y muerte a dosis altas (60-100 Gy). Los cebadores UBC-808, UBC-836 y UBC-840 mostraron el mayor %P, con 42.6%, 34.7% y 28.7%, respectivamente. El análisis de distancia genética mostró que los tratamientos sin irradiación y con irradiación presentaron variación somaclonal. La utilización de gamma durante el cultivo in vitro son una alternativa para ampliar la diversidad genética para el mejoramiento en vainilla. _______________ ABSTRACT: In vitro mutagenesis is an alternative to generate genetic variation in vanilla (Vanilla planifolia Jacks. ex Andrews), which is characterized by low genetic diversity. The objective of this study was to induce somaclonal variation in V. planifolia by gamma radiation and detect it using ISSR (Inter-Simple Sequence Repeat) molecular markers. Shoots previously established in vitro were multiplied in Murashige and Skoog culture medium supplemented with 2 mg L-1 BAP (6-benzylaminopurine). Explants were irradiated with different doses (0, 20, 40, 60, 80 and 100 Gy) of 60Co gamma rays. At 60 d of culture, survival, number of shoots per explant, shoot length and number of leaves per shoot were evaluated. For molecular analysis, ten shoots were used for each dose, along with the donor plant as a control. Eight primers were used and a total of 43 bands were obtained. The percentage of polymorphism (%P) was calculated and a dendrogram based on Jaccard's genetic distance and the neighbor joining clustering method was obtained. Results showed a hormetic effect on the explants, promoting development at low doses (20 and 40 Gy) and inhibition and death at high doses (60-100 Gy). Primers UBC-808, UBC-836 and UBC-840 showed the highest %P, with 42.6%, 34.7% and 28.7%, respectively. Genetic distance analysis showed that treatments without irradiation and with irradiation presented somaclonal variation. The use of gamma rays during in vitro culture is an alternative to broaden genetic diversity for vanilla breeding. | es_MX |
