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.
2004
González-Rodríguez, A.; Bain, J. F.; Golden, J. L.; Oyama, K.
Chloroplast DNA variation in the Quercus affinis-Q. laurina complex in Mexico: Geographical structure and associations with nuclear and morphological variation Artículo de revista
En: Molecular Ecology, vol. 13, iss. 11, pp. 3467-3476, 2004, ISSN: 09621083.
Resumen | Enlaces | Etiquetas: Chloroplast dna, Geographical structure, Hybridization, Mexico, Population history, Quercus
@article{Gonzalez-Rodriguez2004,
title = {Chloroplast DNA variation in the Quercus affinis-Q. laurina complex in Mexico: Geographical structure and associations with nuclear and morphological variation},
author = {A. González-Rodríguez and J. F. Bain and J. L. Golden and K. Oyama},
doi = {10.1111/j.1365-294X.2004.02344.x},
issn = {09621083},
year = {2004},
date = {2004-01-01},
journal = {Molecular Ecology},
volume = {13},
issue = {11},
pages = {3467-3476},
abstract = {The geographical distribution of chloroplast DNA (cpDNA) variation in 39 populations of two hybridizing Mexican red oaks, Quercus affinis and Q. laurina, was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Six haplotypes were identified. Of these, two (H1 and H4), separated by four mutations, had high frequencies (58 and 23% of the individuals, respectively) and were present across the whole geographical range of both species, often co occurring in the same populations. The other four haplotypes were rare, geographically restricted, and are probably derived from the two frequent haplotypes. Latitudinal or other clinal patterns in diversity levels or haplotype composition of populations were not apparent. The pattern of haplotype distribution was characterized by some mosaicism, with contrasting populations often situated in proximity. Average within-population diversity (hS = 0.299) and population differentiation (GST = 0.499) were, respectively, higher and lower than values reported in previous studies of oak species. There was evidence for phylogeographical structure, as indicated by NST (0.566) being significantly higher than GST. Haplotypic variation was largely species-independent, although some very weak associations were detected between haplotypes H1 and H4 and morphological and nuclear molecular variation correspondingly characterizing Q. affinis and Q. laurina. These oaks probably did not experience a marked restriction to one or a few particular subregions of their present range during the last glacial cycle. It is more likely that substantial populations persisted throughout several episodes of climatic change, but experienced recurrent latitudinal and altitudinal migrations which may have caused the widespread distribution of haplotypes H1 and H4 and frequent intermixing of populations.},
keywords = {Chloroplast dna, Geographical structure, Hybridization, Mexico, Population history, Quercus},
pubstate = {published},
tppubtype = {article}
}
The geographical distribution of chloroplast DNA (cpDNA) variation in 39 populations of two hybridizing Mexican red oaks, Quercus affinis and Q. laurina, was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Six haplotypes were identified. Of these, two (H1 and H4), separated by four mutations, had high frequencies (58 and 23% of the individuals, respectively) and were present across the whole geographical range of both species, often co occurring in the same populations. The other four haplotypes were rare, geographically restricted, and are probably derived from the two frequent haplotypes. Latitudinal or other clinal patterns in diversity levels or haplotype composition of populations were not apparent. The pattern of haplotype distribution was characterized by some mosaicism, with contrasting populations often situated in proximity. Average within-population diversity (hS = 0.299) and population differentiation (GST = 0.499) were, respectively, higher and lower than values reported in previous studies of oak species. There was evidence for phylogeographical structure, as indicated by NST (0.566) being significantly higher than GST. Haplotypic variation was largely species-independent, although some very weak associations were detected between haplotypes H1 and H4 and morphological and nuclear molecular variation correspondingly characterizing Q. affinis and Q. laurina. These oaks probably did not experience a marked restriction to one or a few particular subregions of their present range during the last glacial cycle. It is more likely that substantial populations persisted throughout several episodes of climatic change, but experienced recurrent latitudinal and altitudinal migrations which may have caused the widespread distribution of haplotypes H1 and H4 and frequent intermixing of populations.