Nuclear DNA C-values for biodiversity screening: Case of the Lebanese flora

Abstract

The geographic position of Lebanon in the Mediterranean basin at the transition of two major landmasses, Eurasia and Africa, has contributed to its high plant diversity and makes its flora particularly interesting to study. This paper contributes to the plant DNA C-value database of native Lebanese taxa. These data should reinforce biodiversity evaluation, systematic and evolution studies involving processes of speciation such as polyploidisation. C-values have been estimated by flow cytometry using propidium iodide as intercalary fluorochrome stain. Each sample comprised at least five individuals. Where possible, several populations were measured for each species. This study presents C-values for 225 taxa belonging to 55 families and 141 genera. C-values are novel for 193 taxa including 126 plants endemic to the Eastern Mediterranean region. These are the first values for 50 genera. In this panel, genome size ranged from 1C = 0.28 pg in Hypericum thymifolium to 54.69 pg in Fritillaria alfredae. The life growth form and life cycle type are analysed according to the genome size class. Cases of polyploidy are reported for some species usually considered as only diploid. Examination of C-value variation through flow cytometry constitutes a powerful tool to screen taxonomic heterogeneity, opening further investigations.

Keywords::

• Chromosome number
• endemism
• genome size
• Lebanon
• nuclear DNA C-value
• plant diversity
• polyploidy

Acknowledgements

We thank Olivier Catrice for his help in flow cytometry, Fatima Pustahija and Nadine Haddad for the statistical analysis and the students of Saint-Joseph University for their help in plant material collection.

Supplemental data

Supplementary material relating to this article is available online at http://dx.doi.org/10.1080/11263504.2013.861530.

Additional information

Funding

Part of this work was supported by AUF réseau BIOVEG [grant number P2.2092RR707], by UNESCO-L'Oreal for Women in Science Fellowship 2008, UNESCO-HP Brain Gain Initiative 2010 and by the National Council for Scientific Research Lebanon (1 June 2008). This work has benefitted from the facilities of the Imagif Cell Biology Unit of the Gif campus (www.imagif.cnrs.fr) which is supported by the Conseil Général de l'Essonne.