Hummingbirds are important pollinators in Monteverde, Costa Rica, as they are in most neotropical montane cloud forests. In Monteverde, hummingbird-pollinated plants are generally pollen-limited and incapable of autonomous self-pollination. However, many hummingbird-pollinated plants in the Bromeliaceae are capable of autonomous self-pollination. We examined the breeding system and pollination of Pitcairnia brittoniana (Mez), shown previously to be capable of autonomous selfing. We found that fruit and seed set were high in open-, self-, and cross-pollinated treatments, as well as in the autonomous self-pollination treatment. Seed set, but not fruit set was slightly lower among pollinator-excluded flowers from which the anthers or stigma were removed at dawn, the time at which flowers are first receptive to cross-pollination, relative to controls whose anthers and stigmas were unmanipulated. Flowers were visited by two hummingbird species that deposited cumulative cross-pollen loads sufficient for near maximum seed set. Therefore, P. brittoniana has the potential for high levels of either outcrossing or inbreeding in Monteverde. Although the relative competitive abilities of self- and cross-pollen in P. brittoniana are unknown, cross-pollen prepotency is probable. Pitcairnia brittoniana likely maintains a mixed mating system, outcrossing when hummingbirds are active and selfing autonomously when they are scarce.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 136 • No. 3