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Article
The Structure of Morphological and Genetic Diversity in Natural Populations of Carica papaya in Costa Rica
Biotropica: The Journal of Tropical Biology and Conservation (2012)
  • Jenise M. Bauman, Western Washington University
  • Jennifer E. Brown
  • Joseph F. Lawrie
  • Oscar J. Rocha
  • Richard C. Moore
Abstract
In Costa Rica, dioecious Carica papaya has been observed growing in disturbed areas and within secondary lowland forests. Such populations can serve as a reservoir of genetic and morphological diversity for this tropical fruit crop. We quantify the levels and patterns of the diversity of naturally occurring populations of C. papaya and address the demographic history of these populations. We measured 29 vegetative and reproductive morphological traits in situ from 252 plants and found significant heterogeneity among regional populations in the majority of these traits. Significant variation was found among regional populations with respect to fruit size and shape, with plants in the Nicoya Peninsula possessing smaller, less fleshy fruit, a characteristic of previously described wild populations of papaya. We then assessed the levels and patterns of genetic diversity in 164 plants from natural populations and 20 cultivars. Natural populations exhibit a deficiency of heterozygotes; however, this is much more pronounced within the cultivars. Although there is little genetic differentiation among natural populations, we did find evidence of cryptic genetic population structure. Analyses of population demography indicate that these natural populations have undergone a recent genetic bottleneck, followed by recent population expansion, possibly promoted by the transformation of the Costa Rican landscape for agricultural use.
Keywords
  • Dioecy,
  • Microsatellite,
  • Population expansion,
  • Population structure,
  • Tropical fruit crop
Disciplines
Publication Date
March, 2012
Publisher Statement
© 2011 The Author(s). Journal compilation © 2011 by The Association for Tropical Biology and Conservation DOI: 10.1111/j.1744-7429.2011.00779.x
Citation Information
Jenise M. Bauman, Jennifer E. Brown, Joseph F. Lawrie, Oscar J. Rocha, et al.. "The Structure of Morphological and Genetic Diversity in Natural Populations of Carica papaya in Costa Rica" Biotropica: The Journal of Tropical Biology and Conservation Vol. 44 Iss. 2 (2012)
Available at: http://works.bepress.com/jenise_bauman/8/