Resumo

AGUIRRE-LIMON, Verónica et al. Genetic variation of Pinus pinceana Gordon evidence of conectivity in fragmented populations. Rev. mex. de cienc. forestales [online]. 2017, vol.8, n.43, pp.39-63. ISSN 2007-1132.

Pinus pinceana is a Mexican pine species which belongs to the Cembroides subsection. It occurs in a fragmented manner in arid mountainous areas of the Eastern Sierra Madre (SMO). It is currently included in the Mexican Official Standard NOM-059-SEMARNAT-2010 with the Special Protection status. In order to assess the genetic diversity among its populations, the amount of genetic flow, as well as the genetic distance between them, 180 samples obtained from the northernmost locations were analyzed using the random amplification of polymorphic DNA (RAPD) technique. The genetic diversity in the populations was high, with a polymorphism percentage of 94.7 % and a Shannon diversity index of 48 %. The total variation between the populations was 14.8 % (P=0.001). Most of the variation was determined within the populations (85.18 %) as being high and having a low differentiation (Gst = 0.15). This suggests that, although the distribution of the species across the SMO is fragmented and restricted, the interpopulational genetic flow has been sufficient to declare that P. pinceana is not in a vortex of genetic extintion. The genetic distance shows the formation of two groups: one with the populations belonging to the state of Coahulia, and another with those of Nuevo León and Zacatecas: this indicates a larger genetic flow between them than within relation to those of Coahuila and, probably, the influence of a physographic barrier in the Eastern Sierra Madre.

Palavras-chave : Genetic distance; genetic extinction; genetic flow; Pinus pinceana Gordon; RAPD; Eastern Sierra Madre; genetic variation.