Tropical Ecology and Conservation [Monteverde Institute]


Katie Obegi



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Publication Date

September 1999


In this study I looked at reproductive strategies of Besleria princeps (Gesneriaceae). I took population sex ratios from 100 randomly chosen plants over a nine day period and found that individual flowers as well as the population as a whole were protandrous. There was a significant difference in the ratios of males to females from day one to day two. This protandrous system promotes outbreeding thereby reducing the negative effects of inbreeding. In a separate group of plants, I bagged 94 individuals including 162 buds. When the buds opened, I noted their sex and separated them into groups in which I either probed for nectar, removed pollen, or left them alone. I monitored them daily, noting when the sex change occurred from male to female to determine if the plants responded to simulated visitation by pollinators. The group that I probed for nectar switched sex sooner than the control group, which suggests that the flowers switch after their pollen has likely been removed and therefore the chance of inbreeding is reduced. There was a trend among flowers whose pollen was removed to switch sex earlier than the control but it was not statistically significant.


En este estudio, estudie las estrategias de reproducción en Besleria princeps (Gesneriaceae). Tomé proporción de sexos de una población de 100 plantas que yo elegí al azar en un plazo de nueve días y encontré que flores individuales y también la población eran protandria. Hubo una diferencia entre las proporciones de machos y hembras de día uno a día dos. Este sistema de protandria promueve entre cruce reduciendo los efectos negativos de endogamia. Se embolsaron 94 plantas individuales con 162 botones y cuando se abrieron yo hice nota de sus sexos y los separé en grupos en los que revise por néctar, quité polen, o los deje solos. Los revisé cada día, haciendo notas de cuando se dio el cambio de sexo de macho a hembra para determinar si las plantas respondieron a la visita simulada de polinizadores. El grupo que revisé por néctar cambio de sexo más rápido que el grupo control, lo que sugiere que las flores cambian después que su polen ha sido removido y por lo tanto el riesgo de endogamia se reduce. Hubo una tendencia entre las flores en donde el polen fue removido a cambiar de sexo más temprano que el control pero no hubo diferencia estadística.


10 pages

Holding Location

Monteverde Institute


English; Spanish

Media Type



Digital Only





Reproductive strategies of a population of Besleria princeps in the Monteverde cloud forest, September 1999



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