Transcriptome data from silica-preserved leaf tissue reveal gene flow patterns in a Caribbean bromeliad

Background and Aims Transcriptome sequencing is a cost-effective approach that allows researchers to study a broad range of questions. However, to preserve RNA for transcriptome sequencing, tissue is often kept in special conditions, such as immediate ultracold freezing. Here, we demonstrate that RNA can be obtained from 6-month-old, field-collected samples stored in silica gel at room temperature. Using these transcriptomes, we explore the evolutionary relationships of the genus Pitcairnia (Bromeliaceae) in the Dominican Republic and infer barriers to gene flow.Methods We extracted RNA from silica-dried leaf tissue from 19 Pitcairnia individuals collected across the Dominican Republic. We used a series of macro- and micro-evolutionary approaches to examine the relationships and patterns of gene flow among individuals.Key Results We produced high-quality transcriptomes from silica-dried material and demonstrated that evolutionary relationships on the island match geography more closely than species delimitation methods. A population genetic examination indicates that a combination of ecological and geographical features presents barriers to gene flow in Pitcairnia.Conclusions Transcriptomes can be obtained from silica-preserved tissue. The genetic diversity among Pitcairnia populations does not warrant classification as separate species, but the Dominican Republic contains several barriers to gene flow, notably the Cordillera Central mountain range. Premisa del Estudio La sequenciacion de transcriptomas es una tecnica costo-efective que permite estudiar multiples preguntas. Sin embargo, para secuenciar transcriptomas, el tejido suele mantenerse bajo condiciones especiales, como el ultra-congelamiento inmediato. Aqui demostramos que el ARN puede ser obtenido de muestras preservadas en silica a temperatura ambiente. Usando estos transcriptomas exploramos las relaciones evolutivas de Pitcairnia (Bromeliaceae) en la Republica Dominicana e inferimos barreras para el flujo genetico.Metodos Extraimos ARN de tejido preservado en silica de 19 individuos de Pitcairnia colectados en la Republica Dominicana. Utilizamos tecnicas macro y microevolutivas para examinar las relaciones y patrones de flujo genetico entre los individuos.Resultados Clave Produjimos transcriptomas de alta calidad a partir de material preservado en silica y demostramos que las relaciones evolutivas en la isla coinciden mas con la geografia que con la delimitacion de especies actual. Los analisis de genetica de poblaciones indican que factores ecologicos y geograficos son barrera para el flujo genetico.Conclusiones Transcriptomas de alta calidad pueden ser obtenidos de tejido preservado en silica. La diversidad genetica entre las poblaciones de Pitcairnia no amerita una clasificacion en especies separadas, pero la Republica Dominicana contiene varias barreras para el flujo genetico, notablemente, La Cordillera Central.