Species delimitation is an important issue in terms of conservation priorities, especially for narrow endemics under threat of extinction. The Alpine endemics Brassica repanda subsp. glabrescens and subsp. baldensis belong to a highly polymorphic species complex, although their disjunct distribution suggests favourable conditions for independent evolution. In the present study, we applied the unified species concept to test whether the endemics form distinct evolutionary lineages, both from one another and also from the remainder of the complex. Compliance with the criteria of monophyly, diagnosability, and genotypic clustering was examined, primarily by making use of amplified fragment length polymorphism data. Both endemics were indicated as monophyletic by phylogenetic analyses, and diagnostic characters were found for both taxa. Population structure analyses showed clear genetic discontinuity for each of the endemics, with little admixture among the clusters. This evidence indicates that the endemics have acquired multiple properties that satisfy each of the species criteria considered. Hence, we suggest the taxonomic recognition of B. baldensis and B. glabrescens as separate species. Comparative population genetics analyses show the lack of marked genetic structuring within either taxon, as well as low levels of heterozygosity. Conclusions on the status of threat and on recommended conservation actions are drawn.
Lega, M.; Fior, S.; Prosser, F.; Bertolli, A.; Li, M.; Varotto, C. (2012). Application of the unified species concept reveals distinct lineages for disjunct endemics of the Brassica repanda (Brassicaceae) complex. BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, 106 (3): 482-497. doi: 10.1111/j.1095-8312.2012.01887.x handle: http://hdl.handle.net/10449/21188
Application of the unified species concept reveals distinct lineages for disjunct endemics of the Brassica repanda (Brassicaceae) complex
Lega, Margherita;Fior, Simone;Li, Mingai;Varotto, Claudio
2012-01-01
Abstract
Species delimitation is an important issue in terms of conservation priorities, especially for narrow endemics under threat of extinction. The Alpine endemics Brassica repanda subsp. glabrescens and subsp. baldensis belong to a highly polymorphic species complex, although their disjunct distribution suggests favourable conditions for independent evolution. In the present study, we applied the unified species concept to test whether the endemics form distinct evolutionary lineages, both from one another and also from the remainder of the complex. Compliance with the criteria of monophyly, diagnosability, and genotypic clustering was examined, primarily by making use of amplified fragment length polymorphism data. Both endemics were indicated as monophyletic by phylogenetic analyses, and diagnostic characters were found for both taxa. Population structure analyses showed clear genetic discontinuity for each of the endemics, with little admixture among the clusters. This evidence indicates that the endemics have acquired multiple properties that satisfy each of the species criteria considered. Hence, we suggest the taxonomic recognition of B. baldensis and B. glabrescens as separate species. Comparative population genetics analyses show the lack of marked genetic structuring within either taxon, as well as low levels of heterozygosity. Conclusions on the status of threat and on recommended conservation actions are drawn.File | Dimensione | Formato | |
---|---|---|---|
2012 BJLS Lega et al.pdf
solo utenti autorizzati
Licenza:
Tutti i diritti riservati (All rights reserved)
Dimensione
866.52 kB
Formato
Adobe PDF
|
866.52 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.