Journal Article

Round and large: morphological and genetic consequences of artificial selection on the gourd tree <i>Crescentia cujete</i> by the Maya of the Yucatan Peninsula, Mexico

Xitlali Aguirre-Dugua, Luis E. Eguiarte, Antonio González-Rodríguez and Alejandro Casas

in Annals of Botany

Published on behalf of The Annals of Botany Company

Volume 109, issue 7, pages 1297-1306
Published in print June 2012 | ISSN: 0305-7364
Published online April 2012 | e-ISSN: 1095-8290 | DOI: https://dx.doi.org/10.1093/aob/mcs068
Round and large: morphological and genetic consequences of artificial selection on the gourd tree Crescentia cujete by the Maya of the Yucatan Peninsula, Mexico

More Like This

Show all results sharing these subjects:

  • Ecology and Conservation
  • Evolutionary Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Background and Aims

Artificial 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.

Methods

Fifty-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 Results

The 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.

Conclusions

The 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.

Keywords: Artificial selection; Bignoniaceae; Crescentia cujete; domestication; Maya; Mesoamerica; microsatellites; traditional plant management

Journal Article.  7263 words.  Illustrated.

Subjects: Ecology and Conservation ; Evolutionary Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.