Publicaciones

@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}

}