Razafinarivo Norosoa, Rakotomalala J.J., Brown S.C., Bourge M., Hamon Serge, Kochko Alexandre de, Poncet Valérie, Dubreuil Tranchant Christine, Couturon Emmanuel, Guyot Romain, Hamon Perla. (2012). Geographical gradients in the genome size variation of wild coffee trees (Coffea) native to Africa and Indian Ocean islands. Tree Genetics and Genomes, 8 (6), p. 1345-1358. ISSN 1614-2942.
Titre du document
Geographical gradients in the genome size variation of wild coffee trees (Coffea) native to Africa and Indian Ocean islands
Année de publication
2012
Auteurs
Razafinarivo Norosoa, Rakotomalala J.J., Brown S.C., Bourge M., Hamon Serge, Kochko Alexandre de, Poncet Valérie, Dubreuil Tranchant Christine, Couturon Emmanuel, Guyot Romain, Hamon Perla
Source
Tree Genetics and Genomes, 2012,
8 (6), p. 1345-1358 ISSN 1614-2942
The genus Coffea, mainly native to Africa and to the Indian Ocean islands (Mascarocoffea), accounts for 124 species. Genome size data are available for 23 African species. The aim of this study was to assess the genome size of 44 Mascarocoffea species and to investigate possible association with species geographic distribution, stomata traits, and species relationships. 2 C values were measured using flow cytometry. A lyophilization procedure for leaves was tested. The 2 C nuclear DNA content of Mascarocoffea species ranged from 0.96 to 1.41 pg. Coffea mauritiana and Coffea humblotiana have the smallest genomes and Coffea millotii has the largest. Mean 2 C DNA for Mascarocoffea and Africa is 1.19 and 1.43 pg, respectively. The overall DNA values corresponded to two partially overlapped normal distributions: one harboring species from east Africa Mascarocoffea, the other harboring species from west/central Africa. Plotted on a geographical map according to the native origin of species, these values showed a gradient in Madagascar and Africa. Genome sizes increased following a north to southeast gradient in Madagascar and an east to west gradient in Africa. None, or only weak correlations were noted between genome size and stomata parameters. Genetically close species could be highly distinctive in their genome size while divergent species could be similarly sized. The non-random geographic distribution and habitat of species, and the absence of correlation between genome size and genetic relationships, suggest that during Coffea genome evolution, both DNA content increase and/or decrease occurred independently in Africa and in the Indian Ocean Islands.
Plan de classement
Sciences du monde végétal [076]
;
Etudes, transformation, conservation du milieu naturel [082]
Localisation
Fonds IRD [F B010058168]
Identifiant IRD
fdi:010058168
