HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Data Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Nassar, J. M. Articles by Fleming, T. H. Search for Related Content PubMed Articles by Nassar, J. M. Articles by Fleming, T. H. Agricola Articles by Nassar, J. M. Articles by Fleming, T. H.

Population genetic structure of Venezuelan chiropterophilous columnar cacti (Cactaceae)¹

²Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Apdo. Postal 21827, Caracas 1020-A, Venezuela; ³Biology Department, University of Miami, P.O. Box 249118, Coral Gables, Florida 33124 USA; ⁴Departments of Botany and Genetics, University of Georgia, 2502 Plant Sciences, Athens, Georgia 30602 USA

We conducted allozyme surveys of three Venezuelan self-incompatible chiropterophilous columnar cacti: two diploid species, Stenocereus griseus and Cereus repandus, and one tetraploid, Pilosocereus lanuginosus. The three cacti are pollinated by bats, and both bats and birds disperse seeds. Population sampling comprised two spatial scales: all Venezuelan arid zones (macrogeographic) and two arid regions in northwestern Venezuela (regional). Ten to 15 populations and 17–23 loci were analyzed per species. Estimates of genetic diversity were compared with those of other allozyme surveys in the Cactaceae to examine how bat-mediated gene dispersal affects the population genetic attributes of the three cacti. Genetic diversity was high for both diploid (P_s = 94.1–100, P_p = 56.7–72.3, H_s = 0.182–0.242, H_p = 0.161–0.205) and tetraploid (P_s = 93.1, P_p = 76.1, H_s = 0.274, H_p = 0.253) species. Within-population heterozygote deficit was detected in the three cacti at macrogeographic (F_IS = 0.145–0.182) and regional (F_IS = 0.057–0.174) levels. Low genetic differentiation was detected at both macrogeographic (G_ST = 0.043–0.126) and regional (G_ST = 0.009–0.061) levels for the three species, suggesting substantial gene flow among populations. Gene exchange among populations seems to be regulated by distance among populations. Our results support the hypothesis that bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three columnar cacti, a process that enhances levels of genetic diversity within their populations.

Key Words: allozymes • bats • Cactaceae • Cereus • columnar cacti • Pilosocereus • population structure • Stenocereus • Venezuela

This article has been cited by other articles:

				S. M. LAMBERT, E. L. BORBA, M. C. MACHADO, and S. C. D. S. ANDRADE Allozyme Diversity and Morphometrics of Melocactus paucispinus (Cactaceae) and Evidence for Hybridization with M. concinnus in the Chapada Diamantina, North-eastern Brazil Ann. Bot., March 1, 2006; 97(3): 389 - 403. [Abstract] [Full Text] [PDF]

				C. N. Ibarra-Cerdena, L. I. Iniguez-Davalos, and V. Sanchez-Cordero Pollination ecology of Stenocereus queretaroensis (Cactaceae), a chiropterophilous columnar cactus, in a tropical dry forest of Mexico Am. J. Botany, March 1, 2005; 92(3): 503 - 509. [Abstract] [Full Text] [PDF]