Skip to Main Content
Genetic diversity and gene exchange in Pinus oocarpa, a Mesoamerican Pine with resistance to the pitch canker fungus (Fusarium circinatum)Author(s): William S. Dvorak; Kevin M. Potter; Valerie D. Hipkins; Gary R. Hodge
Source: International Journal of Plant Sciences. 170(5): 609-626
Publication Series: Scientific Journal (JRNL)
PDF: Download Publication (4.03 MB)
DescriptionEleven highly polymorphic microsatellite markers were used to determine the genetic structure and levels of diversity in 51 natural populations of Pinus oocarpa across its geographic range of 3000 km in Mesoamerica. The study also included 17 populations of Pinus patula and Pinus tecunumanii chosen for their resistance or susceptibility to the pitch canker fungus based on previous research. Seedlings from all 68 populations were screened for pitch canker resistance, and results were correlated to mean genetic diversity and collection site variables. Results indicate that P. oocarpa exhibits average to above-average levels of genetic diversity (A ¼ 19:82, AR ¼ 11:86, HE ¼ 0:711) relative to other conifers. Most populations were out of Hardy-Weinberg equilibrium, and a high degree of inbreeding was found in the species (FIS ¼ 0:150). Bayesian analysis grouped P. oocarpa into four genetic clusters highly correlated to geography and distinct from P. patula and P. tecunumanii. Historic gene flow across P. oocarpa clusters was observed (Nm ¼ 1:1–2:7), but the most pronounced values were found between P. oocarpa and P. tecunumanii (low-altitude provenances) in Central America (Nm ¼ 9:7). Pinus oocarpa appears to have two main centers of diversity, one in the Eje Transversal Volca´nico in central Mexico and the other in Central America. Introgression between P. oocarpa and P. tecunumanii populations appears to be common. Pinus oocarpa populations showed high resistance to pitch canker (stemkill 3%–8%), a disease that the species has presumably coevolved with in Mesoamerica. Resistance was significantly correlated to the latitude, longitude, and altitude of the collection site but not to any genetic-diversity parameters or degree of admixture with P. tecunumanii.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationDvorak, William S.; Potter, Kevin M.; Hipkins, Valerie D.; Hodge, Gary R. 2009. Genetic diversity and gene exchange in Pinus oocarpa, a Mesoamerican Pine with resistance to the pitch canker fungus (Fusarium circinatum). International Journal of Plant Sciences. 170(5):609–626.
KeywordsPinus tecunumanii, Pinus patula, microsatellite markers, gene flow, biogeography, hybridization.
- Genetic diversity and gene exchange in Pinus oocarpa, a Mesoamerican pine with resistance to the pitch canker fungus (Fusarium circinatum)
- Altitudinal genetic variation among Pinus oocarpa populations in Michoacan, Mexico: implications for seed zoning, conservation, tree breeding and global warming
- Classification of Pinus patula, P. tecunumanii, P. oocarpa, P. caribaea var. hondurensis, and Related Taxonomic Entities
XML: View XML