Phylogeographic and population genetic analyses ofCucurbita moschatareveal divergence of two mitochondrial lineages linked to an elevational gradient
| Autor: | Rafael Lira-Saade, Gabriela Castellanos-Morales, Helena S. Hernández-Rosales, Guillermo Sánchez-de la Vega, Erika Aguirre-Planter, Salvador Montes-Hernández, Luis E. Eguiarte |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Population Plant Science DNA Mitochondrial 010603 evolutionary biology 01 natural sciences Gene flow Cucurbita Genetics education Mexico Phylogeny Ecology Evolution Behavior and Systematics Local adaptation education.field_of_study Genetic diversity biology Genetic Variation biology.organism_classification Phylogeography Haplotypes Evolutionary biology Cucurbita moschata Genetic structure Inbreeding 010606 plant biology & botany |
| Zdroj: | American Journal of Botany. 107:510-525 |
| ISSN: | 1537-2197 0002-9122 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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