Phylogeographic and population genetic analyses of Cucurbita moschata reveal divergence of two mitochondrial lineages linked to an elevational gradient

© 2020 Botanical Society of America..

PREMISE: Domestication usually involves local adaptation to environmental conditions. Cucurbita species are a promising model for studying these processes. Cucurbita moschata is the third major crop in the genus because of its economic value and because it displays high landrace diversity, but research about its genetic diversity, population structure, and phylogeography is limited. We aimed at understanding how geography and elevation shape the distribution of genetic diversity in C. moschata landraces in Mexico.

METHODS: We sampled fruits from 24 localities throughout Mexico. We assessed 11 nuclear microsatellite loci, one mtDNA region, and three cpDNA regions but found no variation in cpDNA. We explored genetic structure with cluster analysis, and phylogeographic relationships with haplotype network analysis.

RESULTS: Mitochondrial genetic diversity was high, and nuclear genetic differentiation among localities was intermediate compared to other domesticated Cucurbita. We found high levels of inbreeding. We recovered two mitochondrial lineages: highland (associated with the Trans-Mexican Volcanic Belt) and lowland. Nuclear microsatellites show that localities from the Yucatan Peninsula constitute a well-differentiated group.

CONCLUSIONS: Mexico is an area of high diversity for C. moschata, and these landraces represent important plant genetic resources. In Mexico this species is characterized by divergence processes linked to an elevational gradient, which could be related to adaptation and may be of value for applications in agriculture. The Isthmus of Tehuantepec may be a partial barrier to gene flow. Morphological variation, agricultural management, and cultural differences may be related to this pattern of genetic structure, but further studies are needed.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:107

Enthalten in:

American journal of botany - 107(2020), 3 vom: 19. März, Seite 510-525

Sprache:

Englisch

Beteiligte Personen:

Hernández-Rosales, Helena S [VerfasserIn]
Castellanos-Morales, Gabriela [VerfasserIn]
Sánchez-de la Vega, Guillermo [VerfasserIn]
Aguirre-Planter, Erika [VerfasserIn]
Montes-Hernández, Salvador [VerfasserIn]
Lira-Saade, Rafael [VerfasserIn]
Eguiarte, Luis E [VerfasserIn]

Links:

Volltext

Themen:

Cucurbitaceae
DNA, Mitochondrial
Evolutionary divergence
Genetic diversity
Genetic resources
Journal Article
Mexico
Research Support, Non-U.S. Gov't
Squash

Anmerkungen:

Date Completed 04.05.2020

Date Revised 05.05.2020

published: Print-Electronic

GENBANK: GQ856148, MN381966, MN381976

Citation Status MEDLINE

doi:

10.1002/ajb2.1424

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM306665867