Revisió d’estudis al·loenzimàtics a Canàries

Julia Pérez de Paz i Juli Caujapé-Castells, investigadors del Jardín Botánico Canario ‘Viera y Clavijo’-Unidad Asociada CSIC de Las Palmas de Gran Canaria, acaben de publicar a la prestigiosa revista Annals of Botany l’article A review of the allozyme dataset for the Canarian endemic flora: causes of the high genetic diversity levels, implications for conservation, on s’avaluen els nivells de diversitat al·loenzimàtica de centenars de poblacions de 123 tàxons en relació amb 27 variables biòtiques i amb la distància de cadascuna de les illes al continent. Es tracta d’un article de revisió profund, amb sòlides aportacions a la resolució a de la tècnica mateixa, a la biogeografia de Canàries i al plantejament d’estratègies de conservació de flora en territoris insulars.

Julia Pérez de Paz i Juli Caujapé-Castells (2013). A review of the allozyme dataset for the Canarian endemic flora: causes of the high genetic diversity levels, implications for conservation. Annals of Botany (2013) doi:10.1093/aob/mct076
First published online: April 21, 2013.

Resum

Background and Aims- Allozyme and reproductive data sets for the Canarian flora are updated in order to assess how the present levels and structuring of genetic variation have been influenced by the abiotic island traits and by phylogenetically determined biotic traits of the corresponding taxa; and in order to suggest conservation guidelines.

Methods- Kruskal–Wallis tests are conducted to assess the relationships of 27 variables with genetic diversity (estimated by A, P, Ho and He) and structuring (GST) of 123 taxa representing 309 populations and 16 families. Multiple linear regression analyses (MLRAs) are carried out to determine the relative influence of the less correlated significant abiotic and biotic factors on the genetic diversity levels.

Key Results and Conclusions- The interactions between biotic features of the colonizing taxa and the abiotic island features drive plant diversification in the Canarian flora. However, the lower weight of closeness to the mainland than of (respectively) high basic chromosome number, partial or total self-incompatibility and polyploidy in the MLRAs indicates substantial phylogenetic constraint; the importance of a high chromosome number is feasibly due to the generation of a larger number of linkage groups, which increase gametic and genotypic diversity. Genetic structure is also more influenced by biotic factors (long-range seed dispersal, basic chromosome number and partial or total self-incompatibility) than by distance to the mainland. Conservation-wise, genetic structure estimates (FST/GST) only reflect endangerment under intensive population sampling designs, and neutral genetic variation levels do not directly relate to threat status or to small population sizes. Habitat protection is emphasized, but the results suggest the need for urgent implementation of elementary reproductive studies in all cases, and for ex situ conservation measures for the most endangered taxa, even without prior studies. In non-endangered endemics, multidisciplinary research is needed before suggesting case-specific conservation strategies. The molecular information relevant for conservation should be conserved in a standardized format to facilitate further insight.

Més informació

Deixa un comentari

L'adreça electrònica no es publicarà. Els camps necessaris estan marcats amb *