Oscar Rocha

Courses Taught

• Tropical Field Biology and Conservation

Current Research

In order to achieve our mission, we have established four main areas of research:

1. Reproductive Ecology. We have study the reproductive biology of multiple species. In particular, we are interested in determining the outcrossing rates and its impact on the genetic structure of selected population.

2. Selective abortion of fruits and seeds. We have also studied the role of selective fruit and seed abortion on the regulation of progeny vigour. In particular, we have examined the relationship of ovule position within the fruit with the vigour of the progeny that they produce.

3. Genetic diversity and conservation of genetic resources. For many years we studied the levels of genetic diversity in plants populations. In order to do so, we selected species with different life histories and determined their levels of variation using molecular markers.

4. Conservation ecology. We also examined the impact of human activities such as habitat fragmentation, changes in land use, and agricultural practices on the reproductive ecology and the genetic structure of plant populations.

Scholarly, Creative and Professional Activities

López, M.R, O.J. Rocha and L.A. Fournier. 1984. Producción de mantillo en una comunidad natural y una de ciprés en el bosque de montano bajo muy húmedo. Rio La Hoja, Heredia, Costa Rica. Turrialba 34: 19-25.

Rocha, O.J. 1985. Germinación, supervivencia, flujo poblacional y reproducción de Bidens pilosa (Compositae) bajo diferentes regímenes agricolas.M.Sc. Thesis, Universidad de Costa Rica, Ciudad Universitaria "Rodrigo Facio".

Rocha, O.J. 1988. Population Dynamics of Bidens pilosa L. Splits, Germany.

Rocha, O.J. 1990. The effects of nonrandom seed abortion on progeny vigor in Phaseolus coccineus L. (Leguminosae). Ph.D. Thesis, The Pennsylvania State University, Pennsylvania, U.S.A.

Rocha, O.J. and A.G. Stephenson 1990 Effects of ovule position on seed production, seed weight, and progeny performance in Phaseolus coccineus L. American Journal of Botany 77: 1320-1329.

Rocha, O.J. and A.G. Stephenson 1991 Effects of nonrandom seed abortion on progeny performance in Phaseolus coccineus L. Evolution 45: 1198-1208.

Rocha, O.J. and A.G. Stephenson 1991 Order of fertilization within the ovary of Phaseolus coccineus L. Sexual Plant Reproduction 4: 126-131.

Rocha, O.J. and A.G. Stephenson 1995. Regulation of flower, fruit, and seed production: Phaseolus coccineus a study case. In: P.C. Hoch and A.G.Stephenson (Eds), Experimental and Molecular Approaches to plant biosystematics. Monograph in Systematic Botany from the Missouri Botanical Gardens. Vol 53.

Rocha, O.J. and Lobo 1996 Genetic variation and differentiation among five populations of the Guanacaste tree (Enterolobium cyclocrapum) in Costa Rica. International Journal of Plant Sciences 157 (2): 234 - 239.

Rocha, O.J. 1996 The effects of achene dimorphism on disperal in Bidens pilosa L. International Journal of Plant Sciences 157 (3): 316 - 322.

Maquet, A., Zoro Bi Irie, O.J. Rocha and J.P. Baudoin 1996 Case studies on breeding systems and its consequences for germplasm conservation. 1. Isozyme diversity in wild lima bean population in central Costa Rica. Genetic Resources and Crop Evolution 43: 309 - 318.

Degreef, J, J.P. Baudoin and O.J. Rocha. 1997. Case studies on breeding systems and its consequences for germplasm conservation. 2. Demography of wild Lima beans in the Central Valley of Costa Rica. Genetic Resources and Crop Evolution 44: 429 - 438.

Rocha, O.J., G. Macaya and J.P. Baudoin. 1997 Causes of local extinctions and recolonization, determined by 3 years of monitoring wild populations of Phaseolus lunatus L. in the Central valley of Costa Rica. Genetic Resources Newsletter 112: 44 - 48.

Rocha, O.J. and J.A. Lobo. 1998. Genetic diversity and outcrossing rates in the Guanacaste tree (Enterolobium cyclocarpum Jacq.) in the dry forest of Costa Rica. In: S. Bruns, S. Mantell, C. Tragardh and A.M. Viana "Recent advances in biotechnology for trees conservation and management" International Foundation for Science. Sweden. Pp. 65 - 81.

Murillo, O and O.J. Rocha. 1999. Gene flow and geographical variation in natural populations of Alnus acuminata spp. Arguta (Belutaceae, Fagales) in Costa Rica and Panama. Revista de Biología Tropical 47: 739 - 753.

Vargas, E.M., G. Macaya, J.P. Baudoin and O.J. Rocha. 2000 . Variation in the content of phaseolin in 37 wild populations of of lima beans (Phaseolus lunatus) in the Central Valley of Costa Rica. Genetic Resources Newsletter 121: 53-58.

Rocha, O.J. 2000. La Biología: una vocación centenaria. Memorias de la Academia Nacional de Ciencias. 5 (3): 3-19.

Platt, K.B., J.A. Mangiafico, O.J. Rocha, M.E. Zaldivar, J. Mora, G. Trueba and W.A. Rowley. 2000. Detection of dengue virus neutralization antibodies in bats from Costa Rica and Ecuador. Journal of Medical Entomology 37: 965-967.

Vargas, E.M., G. Macaya, J.P. Baudoin and O.J. Rocha. 2001. Case studies in breeding systems and its consequences for germplam conservation: Electrophoretic mobility of phaseolins in wild populations of lima beans (Phaseolus lunatus) in the Central Valley of Costa Rica. Genetic Resources and Crop Evolution 48: 109-120.

Rocha O.J. and G. Aguilar. 2001. Variation in the breeding behavior of the dry forest tree Enterolobium cyclocarpum Jacq. (Guanacaste) in Costa Rica: a comparison between trees left in pastures and trees in continuous forest. 2001. The American Journal of Botany 88: 1600-1606.

Rocha O.J. and G. Aguilar. 2001. Reproductive biology of the dry forest tree Enterolobium cyclocarpum Jacq. (Guanacaste) in Costa Rica. 2001. The American Journal of Botany 88: 1607-1614.

Hood, M.E., O.J. Rocha and J. Antonovics. 2001. Differences in teliospore germination patterns of Microbotryum violaceous from European and North American Silene species. Mycological Research 105: 532-536.

Meurrens, F., J. Degreef, O.J. Rocha and J.P Baudoin. 2001. Demographic studies in micro-conservation sites with a view to maintain in situ wild Lima beans (Phaseolus lunatus) in the Central Valley of Costa Rica. Plant Genetic Resources Newsletter 128: 45-50.

Rocha, O.J., J. Degreff, D. Barrantes, E. Castro, G. Macaya. 2002. Metapopulation dynamics of lima beans (Phaseolus lunatus) in the Central Valley of Costa Rica. In: J.M.M. Engels, A.H.D. Brown, and M.T. Jackson (Eds.), Managing Plant Genetic Resources. CABI International, UK,

Degreef, J, O.J. Rocha, T. Vanderborght and J.P. Baudoin. 2002 Soil seed bank and seed dormancy in wild populations of Lima Beans (Phaseolus lunatus): considerations for ex situ and in situ conservation. American Journal of Botany 89: 1644-1650.

Zaldivar, M.E., O.J. Rocha, E Castro and R. Barrantes. 2002 Species diversity of plants grown in gardens of Chibchan Amerindians from Costa Rica. Human Ecology 30: 301-316.

O.J. Rocha. 2003. Breeding systems, gene flow and levels of genetic differentiation in plant populations. Lankesteriana 7: 81-86.

M.J. Perich, O. J. Rocha, N.L. Castro, A.W. Alfaro, K.B. Platt, T.Solano and W.A. Rowley. 2003. Evaluation of the Efficacy ofLambda-Cyhalothrin Applied by Three Spray Application Methods for Emergency Control of Aedes aegypti in Costa Rica. Journal of the American Mosquito Control Association. 19 (1): 58-62.

Cespedes, M., M.V. Gutierrez, N. Holbrooke and O.J. Rocha. 2003. Restoration of genetic diversity in the dry forest tree Swietenia macrophylla (Meliaceae) after pasture abandonment in Costa Rica. Molecular Ecology

Elida M. Vargas, Emilio Castro, Gabriel Macaya and Oscar J. Rocha (Accepted for publication) Variación del tamaño de frutos y semillas en 38 poblaciones silvestres de Phaseolus lunatus L. del Valle Central de Costa Rica. Revista de Biología Tropical 51: 707-724.

Mara Eugenia Zaldivar, Oscar J. Rocha, Gabriel Aguilar, Luis Castro, Emilio Castro, and Ramiro Barrantes (Accepted fro Publication) Genetic variation of cassava (Manihot esculenta) cultivated by Chibchan Amerindians from Costa Rica. Economic Botany 58: 15-24.

In review

Oscar J. Rocha and Braulio Ví­lchez (Submitted) A mast fruiting episode of Peltogyne purpurea in the Osa Peninsula, Costa Rica. Biotropica.

Degreef, J, O.J. Rocha and, J.P. Baudoin. (Submitted) Demography of five wild populations of Lima beans(Phaseolus lunatus) in the Central valley of Costa Rica: implications for in situ conservation. Journal of Ecology

Abdelnour, A., and Oscar J. Rocha (submitted) Genetic characterization of a collection of chayote (Sechium edule Jacq. SW) in Costa Rica using isozyme markers. Genetic Resources and Crop Evolution.

O.J. Rocha and M.E. Zaldivar. Sampling design for dry forest trees. To be submitted to Conservation genetics

Rocha, O.J. The population dynamics of Rivina humilis an understory herb. To be submitted to Revista de Biología Tropical.

Rocha, O.J.; P. Gonzalez and G. Macaya. Distribution of Phaseolus lunatus in the Valle Central of Costa Rica: effects of climatic factors and human disturbances. To be submitted to International Journal of Plant Sciences.

Courses Teaching

Spring 2015

• BSCI 30362 - 001 Intro To Biology Of The Tropic
• BSCI 40600 - 016 Writing In Biological Sciences
• BSCI 50195 - 016 Special Topics In Biology
• BSCI 60198 - 013 Research
• BSCI 60299 - 011 Thesis II
• BSCI 80198 - 004 Research

Summer 2015

• BSCI 10110 - 001 Biological Diversity

Fall 2015

• BSCI 40195 - 004 St : Population And Evolutionar
• BSCI 40374 - 001 Conservation Biology
• BSCI 50195 - 004 St : Population Genetics Evolut
• BSCI 50374 - 001 Conservation Biology
• BSCI 70195 - 004 St : Population And Evolutiona
• BSCI 70374 - 001 Conservation Biology