2017
Oyama, Ken; Herrera-Arroyo, María Luisa; Rocha-Ramírez, Víctor; Benítez-Malvido, Julieta; Ruiz-Sánchez, Eduardo; González-Rodríguez, Antonio
Gene flow interruption in a recently human-modified landscape: The value of isolated trees for the maintenance of genetic diversity in a Mexican endemic red oak Artículo de revista
En: Forest Ecology and Management, vol. 390, pp. 27-35, 2017, ISSN: 03781127.
Resumen | Enlaces | Etiquetas: Forest fragmentation, gene flow, Genetic diversity, Isolated trees, Outcrossing rates, Quercus castanea
@article{Oyama2017,
title = {Gene flow interruption in a recently human-modified landscape: The value of isolated trees for the maintenance of genetic diversity in a Mexican endemic red oak},
author = {Ken Oyama and María Luisa Herrera-Arroyo and Víctor Rocha-Ramírez and Julieta Benítez-Malvido and Eduardo Ruiz-Sánchez and Antonio González-Rodríguez},
url = {http://dx.doi.org/10.1016/j.foreco.2017.01.018},
doi = {10.1016/j.foreco.2017.01.018},
issn = {03781127},
year = {2017},
date = {2017-01-01},
journal = {Forest Ecology and Management},
volume = {390},
pages = {27-35},
publisher = {Elsevier B.V.},
abstract = {Gene flow within and among populations is an important factor to maintain genetic cohesiveness and diversity across landscapes. Nowadays, human land use has led to a large forest conversion, creating many fragmented areas where remnant trees play an important role in conserving biodiversity. In this study, we analyzed the effects of a recent anthropogenic forest fragmentation on the genetic diversity and genetic heterogeneity of pollen pools accepted by individuals of the red oak Quercus castanea growing in forest patches and as isolated trees in central Mexico. Pollen movement was also evaluated by the analysis of outcrossing rates using seven nuclear microsatellites. We assumed that adult trees are remnants of the populations that existed previous to the forest fragmentation, while progenies of these trees are the result of recent reproductive events occurring after the fragmentation. We found high genetic diversity in both adult trees and progenies, even though progenies of isolated trees showed a significant reduction in heterozygosity as compared to their mother trees. However, the results of TWOGENER and mating system analyses indicated similar numbers of pollen donors in the progenies of mother trees from fragments and in isolated trees. Overall, our results suggest that gene flow is still extensive among forest fragments and isolated trees, conferring them a great value for the conservation of genetic diversity and connectivity.},
keywords = {Forest fragmentation, gene flow, Genetic diversity, Isolated trees, Outcrossing rates, Quercus castanea},
pubstate = {published},
tppubtype = {article}
}
Gene flow within and among populations is an important factor to maintain genetic cohesiveness and diversity across landscapes. Nowadays, human land use has led to a large forest conversion, creating many fragmented areas where remnant trees play an important role in conserving biodiversity. In this study, we analyzed the effects of a recent anthropogenic forest fragmentation on the genetic diversity and genetic heterogeneity of pollen pools accepted by individuals of the red oak Quercus castanea growing in forest patches and as isolated trees in central Mexico. Pollen movement was also evaluated by the analysis of outcrossing rates using seven nuclear microsatellites. We assumed that adult trees are remnants of the populations that existed previous to the forest fragmentation, while progenies of these trees are the result of recent reproductive events occurring after the fragmentation. We found high genetic diversity in both adult trees and progenies, even though progenies of isolated trees showed a significant reduction in heterozygosity as compared to their mother trees. However, the results of TWOGENER and mating system analyses indicated similar numbers of pollen donors in the progenies of mother trees from fragments and in isolated trees. Overall, our results suggest that gene flow is still extensive among forest fragments and isolated trees, conferring them a great value for the conservation of genetic diversity and connectivity.
2013
Herrera-Arroyo, M. Luisa; Sork, Victoria L.; González-Rodríguez, Antonio; Rocha-Ramírez, Víctor; Vega, Ernesto; Oyama, Ken
Seed-mediated connectivity among fragmented populations of Quercus castanea (Fagaceae) in a Mexican landscape Artículo de revista
En: American Journal of Botany, vol. 100, iss. 8, pp. 1663-1671, 2013, ISSN: 00029122.
Resumen | Enlaces | Etiquetas: Chloroplast dna, Fagaceae, Forest fragmentation, genetic connectivity, genetic variation, Microsatellites, Quercus castanea
@article{Herrera-Arroyo2013,
title = {Seed-mediated connectivity among fragmented populations of Quercus castanea (Fagaceae) in a Mexican landscape},
author = {M. Luisa Herrera-Arroyo and Victoria L. Sork and Antonio González-Rodríguez and Víctor Rocha-Ramírez and Ernesto Vega and Ken Oyama},
doi = {10.3732/ajb.1200396},
issn = {00029122},
year = {2013},
date = {2013-01-01},
journal = {American Journal of Botany},
volume = {100},
issue = {8},
pages = {1663-1671},
abstract = {Premise of study: Anthropogenic fragmentation is an ongoing process in many forested areas that may create loss of connectivity among tree populations and constitutes a serious threat to ecological and genetic processes. We tested the central hypothesis that seed dispersal mitigates the impact of fragmentation by comparing connectivity and genetic diversity of adult vs. seedling populations in recently fragmented populations of the Mexican red oak Quercus castanea. Methods: Adult individuals, established before fragmentation, and seedlings, established after fragmentation, were sampled at 33 forest fragments of variable size (0.2 to 294 ha) within the Cuitzeo basin, Michoacán state, and genotyped using seven highly polymorphic chloroplast microsatellite markers (cpSSRs). To test whether seed dispersal retains connectivity among fragmented populations, we compared genetic diversity and connectivity networks between adults and progeny and determined the effect of fragment size on these values. • Key results: Seventy haplotypes were identified, 63 in the adults and 60 in the seedlings, with average within-population diversity (h S) values of 0.624 in the adults and 0.630 in the seedlings. A positive correlation of genetic diversity values with fragment size was found in the seedling populations but not in the adult populations. The network connectivity analysis revealed lower connectivity among seedling populations than among adults. The number of connections (edges) as well as other network properties, such as betweenness centrality, node degree and closeness, were significantly lower in the seedlings network. • Conclusions: Habitat fragmentation in this landscape is disrupting seed-dispersal-mediated genetic connectivity among extant populations. © 2013 Botanical Society of America.},
keywords = {Chloroplast dna, Fagaceae, Forest fragmentation, genetic connectivity, genetic variation, Microsatellites, Quercus castanea},
pubstate = {published},
tppubtype = {article}
}
Premise of study: Anthropogenic fragmentation is an ongoing process in many forested areas that may create loss of connectivity among tree populations and constitutes a serious threat to ecological and genetic processes. We tested the central hypothesis that seed dispersal mitigates the impact of fragmentation by comparing connectivity and genetic diversity of adult vs. seedling populations in recently fragmented populations of the Mexican red oak Quercus castanea. Methods: Adult individuals, established before fragmentation, and seedlings, established after fragmentation, were sampled at 33 forest fragments of variable size (0.2 to 294 ha) within the Cuitzeo basin, Michoacán state, and genotyped using seven highly polymorphic chloroplast microsatellite markers (cpSSRs). To test whether seed dispersal retains connectivity among fragmented populations, we compared genetic diversity and connectivity networks between adults and progeny and determined the effect of fragment size on these values. • Key results: Seventy haplotypes were identified, 63 in the adults and 60 in the seedlings, with average within-population diversity (h S) values of 0.624 in the adults and 0.630 in the seedlings. A positive correlation of genetic diversity values with fragment size was found in the seedling populations but not in the adult populations. The network connectivity analysis revealed lower connectivity among seedling populations than among adults. The number of connections (edges) as well as other network properties, such as betweenness centrality, node degree and closeness, were significantly lower in the seedlings network. • Conclusions: Habitat fragmentation in this landscape is disrupting seed-dispersal-mediated genetic connectivity among extant populations. © 2013 Botanical Society of America.