Genetic Variability in Natural Populations of Agave durangensis (Agavaceae) Revealed by Morphological and Molecular Traits

• Published in: The Southwestern naturalist 2013-09, Vol.58 (3), p.314-324
• Main Authors: Almaraz-Abarca, Norma, Delgado-Alvarado, Eli A, Torres-Morán, Martha I, Herrera-Corral, Jesús, Ávila-Reyes, José A, Naranjo-Jiménez, Néstor, Uribe-Soto, José N
• Format: Article
• Language: English
• Subjects: Agavaceae; Agave; Agave durangensis; Biological diversity; Deoxyribonucleic acid; DNA; Evolutionary genetics; Feature s; gene flow; Genetic aspects; Genetic distance; Genetic diversity; Genetic loci; Genetic polymorphisms; Genetic variation; indigenous species; interspecific variation; loci; Molecular genetics; Multiculturalism & pluralism; Phenols; Physiological aspects; Plant genetics; Plant morphology; Plants; Population; Population genetics; Studies; Taxonomy
• ISSN: 0038-4909; 1943-6262
• DOI: 10.1894/0038-4909-58.3.314

Agave durangensis is an endemic species that occurs in a reduced area in southern Durango and northern Zacatecas, Mexico. We analyzed the genetic variability of three populations of the species using two pairs of Inverse-Sequence-Tagged-Repeat primers and nine morphological characters to determine the species of the morphologically variable populations. The primers generated characteristic amplification profiles, which distinguished between populations of A. durangensis and revealed interspecific variability when compared with individuals of A. asperrima. Some incongruence between morphological and molecular variability was detected. High genetic variability was indicated by an elevated level of polymorphism (24.18–61.50%) among 91 genetic loci amplified and by the level of gene diversity (0.0807–0.2337) among populations. Genetic differentiation (0.0328–0.4857), gene flow (0.5294–14.7511), genetic distance (0.0200–0.3019), and genetic identity (0.7653–0.9802) among populations suggested that one of the three populations of A. durangensis is in a present advanced diversification process but may still maintain some level of gene flow with the other two populations. Urgent conservation efforts, including protection from harvest, should be addressed for maintaining the genetic variability of the natural populations of A. durangensis. Agave durangensis es una especie endémica que crece en un área reducida del sur de Durango y norte de Zacatecas, México. Analizamos la variabilidad genética de tres poblaciones de esa especie usando dos pares de iniciadores de los marcadores de Repetición de Secuencias Inversas Marcadas (ISTR por sus siglas en inglés) y nueve atributos morfológicos para determinar las especies de las poblaciones morfológicamente muy variables. Los iniciadores generaron perfiles de amplificación característicos, mostrando su capacidad para distinguir entre poblaciones de A. durangensis y para revelar variabilidad intereespecífica cuando los perfiles se compararon con los de A. asperrima. Incongruencia entre la variabilidad morfológica y la molecular fue detectada. Alta variabilidad genética fue encontrada, indicada por los elevados niveles de polimorfismo (24.18–61.50 %) entre 91 loci genéticos amplificados y por los valores de diversidad génica (0.0807–0.2337) entre poblaciones. Diferenciación genética interpoblacional (0.0328–0.4857), flujo genético (0.5294–14.7511), distancia genética (0.0200–0.3019) y la identidad genética (0.7653–0.9802) sugi