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

Magnolia oblongifolia Palmarola 2016

3. Magnolia oblongifolia (León) Palmarola in Palmarola et al. (2016: 3). Type:— CUBA. Holguín: Monte de la Breña, Sierra de Moa, Moa, Oriente, 1 Jul 1945, León, Alain, Clemente & Crisógono LS-22588 (holotype: HAC ex-LS SV-10692!). Homotypic synonyms: Talauma minor var. oblongifolia León (1950: 5). Talauma minor subsp. oblongifolia (León) Borhidi (1971: 6). Talauma oblongifolia (León) Bisse (1974: 589). Heterotypic synonym: Talauma ophiticola Bisse (1974: 589). Type:— CUBA. Holguín: Baracoa, Mina Iberia, en las orillas del arroyo Iberia, April 1968, Bisse & Köhler HFC-6519 (lectotype: HAJB 634!, designated here; isolectotypes: JE 1224!, 1225!, HAJB 635!). Trees or shrubs up to 14 m tall, 0.23 m in diameter. Leaves with petiole 0.8–3.4 cm, leaf blade 7.9–19.7 × 2.5–6.4 cm, oblong-elliptic to oblanceolate, length-width ratio (2.21–) 2.5–4.66, apex round, retuse-emarginate or acute, base cuneate, adaxial surface dark green, abaxial light green, glabrous, reticulate-veined on both sides, midrib flat above, prominent beneath. Flowers terminal, sepals 3, ovate-linear, obovate or rounded, initially greenish white, up to 3.0 × 2.0 cm, petals 6, cream, in two cycles, the 3 outer petals elliptic up to 2.5 × 1.1 cm, the inner petals narrowly ovate and apiculate, up to 2.3 × 0.7 cm, stamens up to 30, linear, cream to white, from base to connective about 0.5 cm, gynoecium 5–8 carpels, pubescent, brown to ferruginous hairs. Polyfollicle irregular elliptic-rhombic, 3.0–4.5 × 3.0– 4.5 cm. Phenology:— Flowering all year, fruiting February–September. Notes:— In the protologue of T. ophiticola, the type is indicated to be at HAJB, but which of the two specimens is the holotype is not indicated (HAJB 634, 635; Bisse 1974). Palmarola et al. (2016) recognised HAJB 634 as the holotype, but this cannot be considered effective lectotypification (termed “inadvertent lectotypification”) since (as of 1 January 2001) the phrase “designated here” or an equivalent is required (Turland et al. 2018: Art. 7.11). For this reason, T. ophiticola is lectotypified here with the material of Palmarola et al. (2016). As presented here, Magnolia oblongifolia has the same limits as proposed by Bisse (1974, 1988) for T. ophiticola. Therefore, it has a reduced circumscription from that proposed by Palmarola et al. (2016; Fig. 1) because it does not include gatherings considered by Bisse (1974, 1988) as T. oblongifolia (except the type), in which the leaves are on average twice as long as wide. Confusion over M. oblongifolia and T. ophiticola was caused because the latter was based on Bisse & Köhler HFC-6519 (HAJB 634; Fig. 2A), which is similar to the type of T. minor var. oblongifolia (León et al. LS-22588, HAC; Fig. 2B). The types of these two names reflect the morphological variability of this species (Fig. 2). Therefore, the correct name for gatherings considered T. ophiticola by Bisse (1974, 1988) is M. oblongifolia. This confusion was not clarified by Palmarola et al. (2016). Distribution:— Endemic to north-eastern Cuba, Holguín, Guantánamo and Santiago de Cuba Privinces, in rain and pine forest, 0–1,000 m a.s.l., in serpentine soils. Specimens examined: — CUBA. Guantánamo: Baracoa, a 1 km del margen occidental del Toa, entre Tabajó y Bernando, bosque pluvial montano, 18 Apr 1986, Arias et al. HFC-58971 (HAJB); Camino al sur de las Delicias después de la toma de agua del río del Duaba, 21 Jul 2017, Bécquer et al. HFC-89538, HFC 89556 (HAJB); Camino entre arroyo Claro y Vega de la Palma, alrededores del río Arroyo Blanco, 19 Feb 1979, Bisse et al. HFC-39615 (HAJB, JE); Cuchillas del Toa, Sierra del Maguey, pluvisilva y charrascales, 24 Mar 1972, Bisse et al. HFC-22687 (HAJB, JE); Loma Los Guineos, bosque pluvial montano, 14 Apr 1986, Arías et al. HFC-58693 (HAJB); Mirador del Iberia, 5 Jul 2016, Palmarola et al. HFC-89261 (HAJB); Mirador del Iberia, 5 Jul 2016, Palmarola et al. HFC-89262 (HAJB); Mirador del Iberia, 5 Jul 2016, Palmarola et al. HFC-89263 (HAJB); Orillas del Río Báez, cerca de los Naranjos, 21 Jan 1977, Bisse et al. HFC-33839 (HAJB, JE); Palenque: Cuchillas del Toa, Cayo Fortuna pluvisilva cerca del arroyo Manajú, 30 Mar 1972, Bisse & Berazaín HFC-22701 (HAJB, JE); Pluvisilva al sur del Yunque de Baracoa, camino desde el charrascal de la Ermita, 19 Jul 2017, Bécquer et al. HFC-89528-89529 (HAJB); Valle al noreste del Yunque de Baracoa, Feb 1968, Bisse & Köhler HFC-5169 (HAJB); Valle del río Duaba La Ermita, 2 Mar 2012, Greuter et al. 27639 (HAJB); Vega de la Palma, alrededores del río Duaba, 27 Feb 1979, Bisse et al. HFC-40068 (HAJB, JE); Imías, Falda oeste de la loma de Majagua Hueca, 16 Apr 1984, Meyer et al. HFC-53146 (HAJB); Monte Oscuro, 3 Apr 1998, Arías et al. HFC-76464 (HAJB); Palenque, Cuchillas del Toa, charrascos de la Loma de Yarey, 26 Mar 1972, Bisse et al. HFC-22169 (HAJB); Sierra de Imías Palmarito de Yamagua, 17 Apr 1984, Bisse et al. HFC-53300 (HAJB, JE). Holguín: Frank País, Falda norte de la Sierra Cristal subida a Palenque en la zona de Brazo Grande, 7 Apr 1987, Bassler et al. HFC-60533 (HAJB); Falda norte de la Sierra Cristal, al sureste de El Culebro, en la subida al Alto del Cuncuní, 10 Oct 1987, Bassler et al. HFC-60851 (HAJB); Falda norte de la Sierra Cristal, al sureste de El Culebro, subida al Pico el Cielo, 13 Apr 1987, Bassler et al. HFC-61180 (HAJB); Mayarí, Meseta el Toldo, al oeste del primer campamento de los americanos en los alrededores de las cabezadas del río Piloto, 28 Jul 2015, Falcón et al. HFC-88424 (HAJB); Moa: Alto de La Melba, 10 Aug 2017, Palmarola et al. HFC-89586-89589 (HAJB); Camino de Mina Iberia a La Melba, 30 Dec 1968, Bisse & Lippold HFC-16527 (HAJB, JE); Camino entre las Comadres y La Melba, 12 Aug 2017, Palmarola et al. HFC-89582, HFC-89583 (HAJB); Cayo Guam, 15 Feb 2016, Palmarola et al. HFC-89228 (HAJB); Cayo Guam, margen izquierdo del río a 2 km del campismo en dirección al campamento de pioneros, 16 Jul 2017, Bécquer & Testé HFC-89438-89440, (HAJB); Cayo Guam: detrás del campamento de los pioneros, 27 Jun 2016, Palmarola et al. HFC-89239, HFC-89248 (HAJB); Cayo Guam: entre el campismo y la poza del Ché, 27 Jun 2016, Palmarola et al. HFC-89250 (HAJB); En el sendero de El Alto de La Melba, 19 Jun 2017, Falcón et al. HFC-89377 (HAJB); En las orillas del río Jiguaní, cerca del segundo aserrío de la Melba, Apr 1968, Bisse & Köhler HFC-6715 (JE), HFC 6802 (HAJB, JE); Falda norte del Pico El Toldo, 21 Jan 1988, Berazaín et al. HFC-63401 (HAJB); La Melba: falda oeste de la Sierra de Moa, 800-1000 m alto, pluvisilva, 23 Dec 1968, Bisse & Lippold HFC-11612 (JE); Mina Delta, Jul 1949, Hnos. León & Clemente LS-910 (US); Monte de la Breña, 300-500 m alto, pluviosilva, Mar 1968, Bisse & Köhler HFC-6390 (JE); Monte La Breña, alrededores del campamento Los Carboneros, camino al nacimiento del río Yagrumaje, 17 Apr 1981, Bisse et al. HFC-44378 (HAJB, JE); Orillas del río Yagrumaje, cerca del puente en el camino a Moa, Feb 1968, Bisse & Köhler HFC-6002 (HAJB, JE); Playa Moa, 15 Apr 1945, Acuña SV-12417 (US); Pluvisilva 8-10 km camino de la Melba, 1 May 1980, Álvarez et al. HFC-42531 (HAJB); Sierra de Moa, al oeste del Toldo 800-900 m, monte nublado, 14 Aug 1970, Bisse & Lippold HFC-17897 (JE); Sagua de Tánamo, Cupeyal del Norte, Hoyo de Mola, 29 Jul 2016, Falcón et al. HFC-88947 (HAJB); Cupeyal del Norte, Hoyo de Mola, 29 Jul 2016, Falcón et al. HFC-88948, HFC 88950, HFC-88952 HFC-88954 (HAJB). Santiago de Cuba: Segundo Frente, Sierra Cristal, Cabezadas Río San Miguel, Apr 1968, Bisse HFC-8367 (HAJB, JE).Published as part of Testé, Ernesto, García-Beltrán, José Angel, Palmarola, Alejandro, Robert, Thierry & Bécquer, Eldis R., 2023, Taxonomic update of Magnolia subsect. Talauma (Magnoliaceae) from Cuba, pp. 124-132 in Phytotaxa 598 (2) on pages 128-130, DOI: 10.11646/phytotaxa.598.2.2, http://zenodo.org/record/796104

Population structure and genetic diversity of Magnolia cubensis subsp. acunae (Magnoliaceae) : effects of habitat fragmentation and implications for conservation

Genetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk. Such data are particularly important for species affected by habitat fragmentation such as Magnolia cubensis subsp. acunae, a Critically Endangered magnolia subspecies endemic to Cuba. Using genetic data from 67 individuals, we aimed to evaluate the effect of habitat fragmentation on two subpopulations in the Guamuhaya mountain range, in Topes de Collantes Protected Natural Landscape and Lomas de Banao Ecological Reserve. We characterize the structure and genetic diversity of these subpopulations, with the objective of managing their conservation more effectively. We used Landsat satellite images to determine land-cover types at the two locations and calculated indices of habitat fragmentation. For genetic analyses, we extracted DNA from the leaf tissue of individuals from the two subpopulations and used EL microsatellite markers to genotype them. We calculated heterozygosity, allelic richness and the F-statistics, to evaluate genetic variability. The montane rainforest in Topes de Collantes was most affected by habitat fragmentation, with smaller patches of more irregular shapes, compared to submontane forest at this location and both montane and submontane forests in Lomas de Banao. Genetic diversity was higher in Topes de Collantes, but we found no genetic differentiation between subpopulations. Our findings suggest the two subpopulations can be considered a single evolutionary unit and conservation entity. We propose to use individuals from both subpopulations for reinforcement to increase the overall genetic diversity of the subspecies

Population structure and genetic diversity of Magnolia cubensis subsp. acunae (Magnoliaceae): effects of habitat fragmentation and implications for conservation

Abstract Genetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk. Such data are particularly important for species affected by habitat fragmentation such as Magnolia cubensis subsp. acunae, a Critically Endangered magnolia subspecies endemic to Cuba. Using genetic data from 67 individuals, we aimed to evaluate the effect of habitat fragmentation on two subpopulations in the Guamuhaya mountain range, in Topes de Collantes Protected Natural Landscape and Lomas de Banao Ecological Reserve. We characterize the structure and genetic diversity of these subpopulations, with the objective of managing their conservation more effectively. We used Landsat satellite images to determine land-cover types at the two locations and calculated indices of habitat fragmentation. For genetic analyses, we extracted DNA from the leaf tissue of individuals from the two subpopulations and used 11 microsatellite markers to genotype them. We calculated heterozygosity, allelic richness and the F-statistics, to evaluate genetic variability. The montane rainforest in Topes de Collantes was most affected by habitat fragmentation, with smaller patches of more irregular shapes, compared to submontane forest at this location and both montane and submontane forests in Lomas de Banao. Genetic diversity was higher in Topes de Collantes, but we found no genetic differentiation between subpopulations. Our findings suggest the two subpopulations can be considered a single evolutionary unit and conservation entity. We propose to use individuals from both subpopulations for reinforcement to increase the overall genetic diversity of the subspecies

MAGNOLIA_SSR_dataset3_10_CONVERT

Dataset 3 comprises 260 individuals representing 13 populations of the 8 Magnolia taxa of the section Talauma subsection Splendentes (See Veltjen et al. 2018 Table 1: Class. = TAS), genotyped for 10 microsatellite markers (See Supplementary Table S2: marker names indicated with an asterisk; Veltjen et al. 2018)

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

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