Genetic patterns in neotropical magnolias (Magnoliaceae) using de novo developed microsatellite markers

Conserving tree populations safeguards forests since they represent key elements of the ecosystem. The genetic characteristics underlying the evolutionary success of the tree growth form: high genetic diversity, extensive gene flow and strong species integrity, contribute to their survival in terms of adaptability. However, different biological and landscape contexts challenge these characteristics. This study employs 63 de novo developed microsatellite or SSR (Single Sequence Repeat) markers in different datasets of nine Neotropical Magnolia species. The genetic patterns of these protogynous, insect-pollinated tree species occurring in fragmented, highly-disturbed landscapes were investigated. Datasets containing a total of 340 individuals were tested for their genetic structure and degree of inbreeding. Analyses for genetic structure depicted structuring between species, i.e. strong species integrity. Within the species, all but one population pair were considered moderate to highly differentiated, i.e. no indication of extensive gene flow between populations. No overall correlation was observed between genetic and geographic distance of the pairwise species’ populations. In contrast to the pronounced genetic structure, there was no evidence of inbreeding within the populations, suggesting mechanisms favouring cross pollination and/or selection for more genetically diverse, heterozygous offspring. In conclusion, the data illustrate that the Neotropical Magnolias in the context of a fragmented landscape still have ample gene flow within populations, yet little gene flow between populations

Integrating morphological and genetic limits in the taxonomic delimitation of the Cuban taxa of Magnolia subsect. Talauma (Magnoliaceae)

An accurate taxa delimitation, based on a full understanding of evolutionary processes involved in taxa differentiation, can be gained from a combination of ecological, morphological, and molecular approaches. The taxonomy of Magnolia subsect. Talauma in Cuba has long been debated and exclusively based on traditional morphological study of a limited number of individuals. A more accurate description of leaf morphology variation using geometric morphometrics combined with genetic data could bring consistency to taxa delimitation in this group. Leaf samples for the morphological (243) and genetic (461) analyses were collected throughout the entire distribution range. The variability of each taxon was analyzed through multivariate and geometric morphometry, and 21 genetic markers (SSR). The observed leaf morphological variability was higher than previously described. Morphological and genetic classifications were highly congruent in two out of four taxa. Our data brought evidence that Magnolia orbiculata can be considered a true species with very clear genetic and morphological limits. The main taxonomic issues concern the north-eastern Cuban populations of Magnolia subsect. Talauma. The data supported the existence of two clear groups: corresponding mainly to M. minor-M. oblongifolia and T. ophiticola. However, these two groups cannot be considered fully delimited since genetic markers provided evidence of genetic admixture between them. Due to the likely absence of, at least strong, reproductive barriers between these three taxa, we propose therefore to consider them as a species complex

MAGNOLIA_SSR_dodecapetala21_CONVERT

This file includes SSR/microsatellite genotype data of 40 individuals of 2 populations of Magnolia dodecapetala: 20 individuals per population. DNA of the 40 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the forest of the Lesser Antilles. The 40 individuals were genotyped using 21 de novo developed microsatellites

MAGNOLIA_SSR_cubensis31_CONVERT

This file includes SSR/microsatellite genotype data of 20 individuals of 1 population of Magnolia cubensis subspecies cubensis. DNA of the 20 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the Cuban forest. The 20 individuals were genotyped using 31 de novo developed microsatellites

MAGNOLIA_SSR_lacandonica23_CONVERT

This file includes SSR/microsatellite genotype data of 40 individuals of 2 populations of Magnolia lacandonica: 20 individuals per population. DNA of the 40 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the forests of Mexico. The 40 individuals were genotyped using 23 de novo developed microsatellites

MAGNOLIA_SSR_ekmanii31_CONVERT

This file includes SSR/microsatellite genotype data of 40 individuals of 2 populations of Magnolia ekmanii: 20 individuals per population. DNA of the 40 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the forest of Haiti. The 40 individuals were genotyped using 31 de novo developed microsatellites

MAGNOLIA_SSR_hamorii24_CONVERT

This file includes SSR/microsatellite genotype data of 40 individuals of 2 populations of Magnolia hamorii: 20 individuals per population. DNA of the 40 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the forest of the Dominican Republic. The 40 individuals were genotyped using 24 de novo developed microsatellites

MAGNOLIA_SSR_domingensis23_CONVERT

This file includes SSR/microsatellite genotype data of 40 individuals of 2 populations of Magnolia domingensis: 20 individuals per population. DNA of the 40 individuals was extracted from leaves using the CTAB method. The leaves were dried on silica-gel and collected from trees in the forest of the Dominican Republic. The 40 individuals were genotyped using 23 de novo developed microsatellites