Resumo

GUTIERREZ-ORTEGA, José Said; KAJITA, Tadashi  e  MOLINA-FREANER, Francisco E.. Conservation genetics of an endangered cycad, Dioon sonorense (Zamiaceae): Implications from variation of chloroplast DNA. Bot. sci [online]. 2014, vol.92, n.3, pp.433-439. ISSN 2007-4476.

The endemic species Dioon sonorense comprises the northernmost group of populations of Dioon, in Sonora, Mexico. Although it is endangered, only the southern populations are protected within a preservation area, while the remaining populations have not been taken into account in management plans or genealogical studies. Describing the intraspecific genealogy and the geographical structure of the genetic variation of D. sonorense may help in the identification of units for further conservation. Therefore, the main objective of this study was to describe the intraspecific genealogy of populations throughout the range of distribution of the endangered species D. sonorense, using haplotypes of the trnL-F spacer of the cpDNA. In addition, the levels of diversity of the employed molecular marker were estimated. Low levels of variability were recorded and at least two evolutionary units, corresponding to each haplotype, were identified as components of the species. The inclusion of northern populations into conservation programs is recommended. In order to integrate these findings to the genealogy of genus Dioon, trnL-Fsequences of all the remaining species were merged and analyzed. An ancestral haplotype with wide distribution was detected in several species and one haplotype in D. sonorense was found shared with its sister species, D. tomasellii. This work represents a first attempt to reconcile a genealogical approach in the identification of important centers of genetic diversity of Mexican cycads.

Palavras-chave : chloroplast DNA; conservation genetics; Dioon sonorense; endangered species.

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