Pollination biology and breeding systems of a tropical palm Astrocaryum vulgare in Guyana.

摘要

The pollination syndrome approach integrates characteristics of flowers and their pollinators into an evolutionary framework, focusing attention on attributes of potential adaptive significance. But the use of pollination syndromes to predict probable pollinators of plant species based on floral traits has recently come under attack. This ensues because few pollination systems are so specialized that only one pollinator can effect fertilization. Thus caution must be taken when predicting potential pollinators for plants based solely on the knowledge of blossom classes and floral traits. I used the syndrome concept to identify potential pollinators of a tropical palm, Astrocaryum vulgare in Guyana, and then tested those predictions experimentally. The flowers of A. vulgare displayed traits typical of the beetle pollination syndrome. The protogynous inflorescences produced heat during a nocturnal anthesis, odor was released at the beginning of anthesis, numerous stamens were produced, and beetles used the inflorescences as feeding and mating sites. Insect visitors to A. vulgare inflorescences included Coleoptera, Hymenoptera, Diptera, and Orthoptera. However, Nutidulidae and Curculionidae beetles were the exclusive insect pollinators. Pollination treatments showed that self pollination was possible, and wind also effected pollination. Fruit set was significantly higher for flowers visited by insects. However, regarding this species as strictly cantharophilous based on its pollination syndrome classification highlights the danger of inferring potential pollinators without empirical evidence. Astrocaryum vulgare also exhibited floral traits indicative of wind pollination, illustrating the imprecise nature or the syndrome concept whereby various floral traits simultaneously 'fit' into different categories. Thus, the predictive value of potential pollinators based on a pollination syndrome approach for A. vulgare was inadequate.