Ecological interactions affecting the evolutionof plant mating systems: Current research and future directions
Quesada, Mauricio , Lobo, Jorge , Rosas, Fernando , Herrerias-Diego, Yvonne , Fuchs, Eric .
Human impacts on pollination, repoduction, mating systems and inbreeding in tropical trees.
Deforestation and forest fragmentation are the main causes of destruction of tropical forest around the world. Fragmentation of natural habitats is predicted to disrupt animal pollination and negatively affect sexual reproduction of tropical trees because most species are animal pollinated, obligate outcrossing and self-incompatible. Consequently, it is of conservation interest to determine the effects of forest fragmentation on pollination, reproduction, mating patterns and inbreeding in tropical trees. I present the results of the effects of forest fragmentation on pollination, mating patterns and gene flow of the tropical trees Ceiba aesculifolia (Malvaceae), Paquira quinata (Malvaceae), and Sweitennia humilis (Meliaceae). These studies compared the effects of fragmentation in two habitat conditions using molecular markers: (1) isolated trees in disturbed areas and 2) trees in undisturbed mature forest in Mexico and Costa Rica. In Ceiba aesculifolia, we found consistently high outcrossing rates across a four year study in both habitat conditions. However, relatedness of progeny was consistently greater for trees in forest fragments across years. We found high levels of genetic structure of pollen pools in all populations with greater values in isolated trees. Pollination frequency varied between forest conditions but did not affect the mating patterns. In Pachira quinata the progeny of trees from continuous forest is produced under higher levels of outcrossing and is sired by more pollen donors than trees in isolation. In Swietenia humilis, allelic richness of seeds is lower in isolated populations than in continuous forest. This pattern is not true for adults. Likewise pollen pool structure is greater in isolated patches than in continuous forest. Accordingly, the effective number of pollen donors and actual number of pollen sources are higher in the forest than in fragmented stands. In general, there is a consistent reduction in the number of pollen donors involved in pollination, and greater inbreeding in trees from forest fragments for all three species.
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web site of Mauricio Quesada
1 - Universidad Nacional Autonoma De Mexico, Apartado Postal 27-3 (Xangari), Morelia, Michoacan, Mexico
2 - Universidad de Costa Rica, Escuela de Biología, San Pedro, SanJose, 1000, Costa Rica
3 - Universidad Autónoma del Estado de Hidalgo, Centro de Investigaciones Biológicas, Pachuca, Hidalgo, 42084, México
4 - Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Biología, Morelia, Michoacan, 58030, Mexico
5 - Universidad de Costa Rica, Escuela de Biologia, San Pedro, San Jose, 1000, Costa Rica
Presentation Type: Symposium or Colloquium Presentation
Location: Delaware D/Hyatt
Date: Tuesday, July 10th, 2012
Time: 3:05 PM