Population structure and genetic diversity of Magnolia cubensis subsp. acunae (Magnoliaceae): effects of habitat fragmentation and implications for conservation M AJELA H ERNÁNDEZ ,A LEJANDRO P ALMAROLA ,E MILY V ELTJEN P IETER A SSELMAN ,E RNESTO T ESTÉ ,I SABEL L ARRIDON M ARIE -S TÉPHANIE S AMAIN and L UIS R. G ONZÁLEZ -T ORRES Abstract Genetic data on threatened plant populations can facilitate the development of adequate conservation strate- gies 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  individuals, we aimed to evaluate the effect of habi- tat 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 sub- populations, with the objective of managing their conser- vation more effectively. We used Landsat satellite images to determine land-cover types at the two locations and calcu- lated indices of habitat fragmentation. For genetic analyses, we extracted DNA from the leaf tissue of individuals from the two subpopulations and used  microsatellite markers to genotype them. We calculated heterozygosity, allelic rich- ness and the F-statistics, to evaluate genetic variability. The montane rainforest in Topes de Collantes was most affect- ed 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 subpopu- lations 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. Keywords Conservation genetics, Cuba, fragmentation indices, Magnolia cubensis subsp. acunae, magnolias, micro- satellites, simple sequence repeats markers Supplementary material for this article is available at doi.org/./SX Introduction G enetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk (Hedrick, ). This is particularly important for species affected by habitat frag- mentation, which reduces the number of individuals per population and leads to isolation between populations, raising the probability of local extinction (Heinken & Weber, ). The genus Magnolia is represented in Cuba by seven endemic taxa (Palmarola et al., ). The Critically Endangered subspecies Magnolia cubensis subsp. acunae Imkhan. is endemic to the Guamuhaya mountain range (González-Torres et al., , ) and is threatened by deforestation and land conversion for cattle farming and coffee production. Recent studies on the distribution and conservation status of the subspecies’ populations (Palmarola et al., ; Granado, ) reported that the two main subpopulations have  and  individuals, respectively. However, there is no information on genetic diversity, the degree of habitat fragmentation or the interaction between these factors. Our study aimed to evaluate the effect of habitat fragmentation on the structure and genetic diver- sity of the M. cubensis subsp. acunae subpopulations in the Guamuhaya mountain range, to support effective conservation management of this subspecies. MAJELA HERNÁNDEZ (Corresponding author, orcid.org/0000-0002-1142-5296) Universidad de La Habana, Facultad de Biología, Calle 25 e/I y J, Vedado, La Habana, Cuba. E-mail majelahr@gmail.com ALEJANDRO PALMAROLA and ERNESTO TESTÉ Universidad de La Habana, Jardín Botánico Nacional, La Habana, Cuba EMILY VELTJEN† ( orcid.org/0000-0002-3170-3345) and PIETER ASSELMAN Systematic and Evolutionary Botany Lab, Department of Biology, Ghent University, Ghent, Belgium ISABEL LARRIDON*( orcid.org/0000-0003-0285-722X) Royal Botanic Gardens, Kew, Richmond, UK MARIE-STÉPHANIE SAMAIN* ( orcid.org/0000-0002-7530-9024) Red de Diversidad Biológica del Occidente Mexicano, Instituto de Ecología, A.C., Pátzcuaro, Michoacán, México LUIS R. GONZÁLEZ-TORRES‡ Department of Biology, The University of British Columbia, New Westminster, Canada *Also at: Ghent University, Ghent, Belgium †Also at: Ghent University Botanical Garden, Ghent, Belgium ‡Also at: Douglas College, New Westminster, Canada Received  November . Revision requested  January . Accepted  May . Oryx, Page 1 of 9 © 2020 Fauna & Flora International doi:10.1017/S003060531900053X https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060531900053X Downloaded from https://www.cambridge.org/core. IP address: 107.150.0.66, on 18 Apr 2020 at 04:14:49, subject to the Cambridge Core terms of use, available at