Molecular characterization of mahogany tree (Swietenia macrophylla King, Meliaceae) in the remnant natural forest of Ecuador

ABSTRACT

The Swietenia macrophylla King (Meliaceae) mahogany tree is widely spread in the neotropics. In Ecuador, it has a wide distribution range from the coastal zone to the Amazon. The mahogany tree is an endangered species due the overexploitation of the high commercial value of its wood. This study is aimed to characterize the Simple Sequence Repeat (SSR) variability of 123 trees selected from six provinces of Ecuador. The results showed that the natural mahogany population had a low level of genetic diversity (A = 6.9; Ho = 0.39; He = 0.43) and a significant heterozygous deficit inbreeding coefficient (F = 0.16). The probability of identity (PI) of the 12 microsatellite markers was low 4.3 × 10⁻⁹ and the cumulative exclusion probability of 99.99%. Additionally, the relatedness coefficient among individuals was −0.010 (se = 0.004). The genetic diversity among populations was moderate (ΦST = 8%). In addition, the structure analysis showed two genetic groups; however, it was possible to distinguish admixture within the entire range evaluated. These results show the need to establish strategies that allow the recovery and increase of the genetic diversity in natural populations, especially with the selection of trees to harvest seeds, as well as crossing the tree genetic pool to recombine their diversity.

KEYWORDS:

• Mahogany
• genetic variability
• heterozygosity
• SSR

Acknowledgments

We would like to thank Petty Officer First Class (PO1) Mauricio Zambrano Pinoargote, Virginia Beach, USA; to Ezio Zambrano Limongi M.A. American Studies from the Universita degli studi di Torino, Italy and Mr David Trojniar for English proofreading the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

RL and JPM led this investigation and analyzed the raw data as well administered the funds of this research; MP, BN, and RL performed all the sampling and fieldwork; JPM, EM, and BC contributed with the statistical and genetical analysis; EM, JB, and SM performed the laboratory work and sampling processes. All authors read and approved the final manuscript.

Additional information

Funding

This work was supported by the Estación Experimental Litoral Sur y Estación Experimental Portoviejo INIAP, Proyect: Preservación de especies maderables nativas en peligro de extinción en el ecosistema de bosque seco del Litoral ecuatoriano; Programa de Conservación de Especies Amenazadas en Peligro de Extinción de la Facultad de Ingeniería Agronómica de la Universidad Técnica de Manabí and Centro de Estudios en Alimentos Procesados (CEAP), ANID Programa Regional R19A10001, Talca, Chile.