Publicaciones

@article{nokey,

title = {Anthropogenic dispersion of selected germplasm creates a geographic mosaic of contrasting maternal lineages in Crescentia cujete from Mesoamerica},

author = {Xitlali Aguirre-Dugua and Jesús Llanderal-Mendoza and Antonio González-Rodríguez and Luis E. Eguiarte and Alejandro Casas},

doi = {10.1007/s11295-018-1230-8},

issn = {16142950},

year  = {2018},

date = {2018-01-01},

journal = {Tree Genetics and Genomes},

volume = {14},

issue = {2},

publisher = {Springer Verlag},

abstract = {The modification of the genetic/phenotypic composition of plant populations through artificial selection occurs both through time and space. We analyzed the role of human dispersal on the geographic distribution of maternal lineages of Crescentia cujete in Mesoamerica. We sampled 28 homegarden (224 individuals) and 12 wild populations (159 individuals). Semi-structured interviews provided information on the origin of cultivated trees. Six chloroplast microsatellites allowed for the identification of 21 haplotypes, four of them exclusively in 83% of homegarden trees. Wild haplotypes from local C. cujete and Crescentia alata were found at low frequencies (17%) under cultivation. Cultivated and wild haplotypes constituted two different haplogroups. Accordingly, barriers to seed dispersal were detected among neighboring cultivated and wild populations. Recorded events of human dispersal of cuttings and seeds attaining up to > 200 km agreed with homegardens’ lower diversity (Nei’s h = 0.55, dropping to 0.32 when excluding wild haplotypes). Wild populations displayed high diversity (h = 0.71) and isolation by distance, in agreement with physiographic provinces. Our results support the native status of wild C. cujete and a Pre-Columbian introduction of cultivated lineages that generated a novel genetic mosaic superimposed on native maternal lineages. The results reveal the active role of farmers in maintaining the identity of cultivated lineages through time, while chloroplast capture from local congeners has increased the diversity of maternal lineages under cultivation. Additional data are needed on the origins of cultivated lineages, but our results contribute new insights into tree domestication in this center of crop diversity.},

keywords = {Bignoniaceae, Crescentia cujete, Homegarden, Mesoamerica, Perennial, Tree domestication},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phylogeography and population differentiation in the Psittacanthus calyculatus (Loranthaceae) mistletoe: a complex scenario of climate–volcanism interaction along the Trans-Mexican Volcanic Belt},

author = {María José Pérez-Crespo and Juan Francisco Ornelas and Antonio González-Rodríguez and Eduardo Ruiz-Sanchez and Antonio Acini Vásquez-Aguilar and Santiago Ramírez-Barahona},

doi = {10.1111/jbi.13070},

issn = {13652699},

year  = {2017},

date = {2017-01-01},

journal = {Journal of Biogeography},

volume = {44},

issue = {11},

pages = {2501-2514},

publisher = {Blackwell Publishing Ltd},

abstract = {Aim: The formation of the Trans-Mexican Volcanic Belt (TMVB) played an important role in driving inter- and intraspecific diversification at high elevations. However, Pleistocene climate changes and ecological factors might also contribute to plant genetic structuring along the volcanic belt. Here, we analysed phylogeographical patterns of the parrot-mistletoe Psittacanthus calyculatus to determine the relative contribution of these different factors. Location: Trans-Mexican Volcanic Belt. Methods: Using nuclear and chloroplast DNA sequence data for 370 individuals, we investigate the genetic differentiation of 35 populations across the species range. We conducted phylogenetic, population and spatial genetic analyses of P. calyculatus sequences along with ecological niche modelling and Bayesian inference methods to gain insight into the structuring of genetic variation of these populations. Results: Our analyses revealed population structure with three genetic groups corresponding to individuals from Oaxaca and those from the central-eastern and western TMVB regions. A significant genetic signal of demographic expansion, an east-to-west expansion predicted by species distribution modelling, and approximate Bayesian computation analyses strongly supported a scenario of habitat isolation and invasion of TMVB by P. calyculatus during the late-Pleistocene. Main conclusions: The genetic differentiation of P. calyculatus may be explained by the combined effects of (1) geographical isolation linked to the effects of the glacial/interglacial cycles and environmental factors, driving genetic differentiation from congeners into more xeric vegetation and (2) the invasion of TMVB from east to west, suggesting a role for both colonization and glacial/interglacial cycles models.},

keywords = {Loranthaceae, Mesoamerica, Mexico, Mistletoes, Phylogeography, Pleistocene, Psittacanthus, Trans-Mexican Volcanic Belt},

pubstate = {published},

tppubtype = {article}

}

@article{Parra2015,

title = {Spatial distribution of genetic variation of Stenocereus pruinosus (Otto) Buxb. in Mexico: analysing evidence on the origins of its domestication},

author = {Fabiola Parra and Alejandro Casas and Víctor Rocha and Antonio Gonzàlez-Rodríguez and Salvador Arias-Montes and Hernando Rodríguez-Correa and Janet Tovar},

doi = {10.1007/s10722-014-0199-x},

issn = {15735109},

year  = {2015},

date = {2015-01-01},

journal = {Genetic Resources and Crop Evolution},

volume = {62},

issue = {6},

pages = {893-912},

abstract = {We studied populations of Stenocereus pruinosus throughout Mexico, a species important for its edible fruit. The Tehuacán Valley is setting of ancient and the currently most active management of S. pruinosus; we hypothesized Tehuacán as the original area of domestication of S. pruinosus and expected to find there its highest genetic variation and original source of genes of cultivated plants. Through nuclear microsatellite loci we studied spatial distribution of genetic variation and population differentiation. We sampled wild and managed populations of the Central-western (Tehuacán, Central Valleys and Tehuantepec, Oaxaca), north-eastern (Huasteca) and south-eastern (Chiapas) regions. Differences among regions and populations were compared through homogeneity and exact test for FIS , AMOVA, Bayesian analysis, and genetic barriers. A niche analysis allowed corroborating taxonomic identity of populations. The highest genetic diversity was in Tehuantepec (HE = 0.841), decreasing towards the extremes of distribution (HE = 0.242 in Huasteca},

keywords = {Centre of origin, Columnar cacti, domestication, Genetic resources conservation, Mesoamerica, Stenocereus pruinosus},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Round and large: Morphological and genetic consequences of artificial selection on the gourd tree Crescentia cujete by the Maya of the Yucatan Peninsula, Mexico},

author = {Xitlali Aguirre-Dugua and Luis E. Eguiarte and Antonio González-Rodrgíuez and Alejandro Casas},

doi = {10.1093/aob/mcs068},

issn = {03057364},

year  = {2012},

date = {2012-01-01},

journal = {Annals of Botany},

volume = {109},

issue = {7},

pages = {1297-1306},

abstract = {Background and AimsArtificial selection, the main driving force of domestication, depends on human perception of intraspecific variation and operates through management practices that drive morphological and genetic divergences with respect to wild populations. This study analysed the recognition of varieties of Crescentia cujete by Maya people in relation to preferred plant characters and documents ongoing processes of artificial selection influencing differential chloroplast DNA haplotype distribution in sympatric wild and home-garden populations. MethodsFifty-three home gardens in seven villages (93 trees) and two putative wild populations (43 trees) were sampled. Through semi-structured interviews we documented the nomenclature of varieties, their distinctive characters, provenance, frequency and management. Phenotypic divergence of fruits was assessed with morphometric analyses. Genetic analyses were performed through five cpDNA microsatellites. Key ResultsThe Maya recognize two generic (wild/domesticated) and two specific domesticated (white/green) varieties of Crescentia cujete. In home gardens, most trees (68%) were from domesticated varieties while some wild individuals (32%) were tolerated. Cultivation involves mainly vegetative propagation (76%). Domesticated fruits were significantly rounder, larger and with thicker pericarp than wild fruits. Haplotype A was dominant in home gardens (76%) but absent in wild populations. Haplotypes B-F were found common in the wild but at low frequency (24%) in home gardens. ConclusionsThe gourd tree is managed through clonal and sexual propagules, fruit form and size being the main targets of artificial selection. Domesticated varieties belong to a lineage preserved by vegetative propagation but propagation by seeds and tolerance of spontaneous trees favour gene flow from wild populations. Five mutational steps between haplotypes A and D suggest that domesticated germplasm has been introduced to the region. The close relationship between Maya nomenclature and artificial selection has maintained the morphological and haplotypic identity (probably for centuries) of domesticated Crescentia despite gene flow from wild populations. © The Author 2012. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.},

keywords = {Artificial selection, Bignoniaceae, Crescentia cujete, domestication, Maya, Mesoamerica, Microsatellites, traditional plant management},

pubstate = {published},

tppubtype = {article}

}

@article{Parra2010,

title = {Evolution under domestication: Ongoing artificial selection and divergence of wild and managed Stenocereus pruinosus (Cactaceae) populations in the Tehuacán Valley, Mexico},

author = {Fabiola Parra and Alejandro Casas and Juan Manuel Peñaloza-Ramírez and Aurea C. Cortés-Palomec and Víctor Rocha-Ramírez and Antonio González-Rodríguez},

doi = {10.1093/aob/mcq143},

issn = {10958290},

year  = {2010},

date = {2010-01-01},

journal = {Annals of Botany},

volume = {106},

issue = {3},

pages = {483-496},

abstract = {Background and AimsThe Tehuacán Valley in Mexico is a principal area of plant domestication in Mesoamerica. There, artificial selection is currently practised on nearly 120 native plant species with coexisting wild, silvicultural and cultivated populations, providing an excellent setting for studying ongoing mechanisms of evolution under domestication. One of these species is the columnar cactus Stenocereus pruinosus, in which we studied how artificial selection is operating through traditional management and whether it has determined morphological and genetic divergence between wild and managed populations.MethodsSemi-structured interviews were conducted with 83 households of three villages to investigate motives and mechanisms of artificial selection. Management effects were studied by comparing variation patterns of 14 morphological characters and population genetics (four microsatellite loci) of 264 plants from nine wild, silvicultural and cultivated populations.Key ResultsVariation in fruit characters was recognized by most people, and was the principal target of artificial selection directed to favour larger and sweeter fruits with thinner or thicker peel, fewer spines and pulp colours others than red. Artificial selection operates in agroforestry systems favouring abundance (through not felling plants and planting branches) of the preferred phenotypes, and acts more intensely in household gardens. Significant morphological divergence between wild and managed populations was observed in fruit characters and plant vigour. On average, genetic diversity in silvicultural populations (HE = 0·743) was higher than in wild (HE = 0·726) and cultivated (HE = 0·700) populations. Most of the genetic variation (90·58 ) occurred within populations. High gene flow (NmFST > 2) was identified among almost all populations studied, but was slightly limited by mountains among wild populations, and by artificial selection among wild and managed populations.ConclusionsTraditional management of S. pruinosus involves artificial selection, which, despite the high levels of gene flow, has promoted morphological divergence and moderate genetic structure between wild and managed populations, while conserving genetic diversity. © The Author 2010.},

keywords = {Cactaceae, Columnar cacti, crop evolution, domestication, Mesoamerica, Stenocereus pruinosus, traditional plant management},

pubstate = {published},

tppubtype = {article}

}