Articles
Genetic characterization to guarantee varietal authenticity between citrus germplasms and proposal of an international database development
Article number
1448_26
Pages
211 – 216
Language
English
Abstract
Authentication of the varietal identity of genetic resources is essential to guarantee the exchange of biological material and enable comparison of plant behaviour between different sites and environments.
As part of the conservation of citrus genetic resources at the INRAE-Cirad Biological Resource Center (BRC) in San Giuliano, France, a genetic and phenotypic characterization procedure was set up.
Genetic characterization was carried out on 600 accessions, using 42 microsatellite markers (SSR) whose allelic profiles were revealed by denaturing capillary separation (ABI 300). SSR polymorphism is absent in species whose varietal diversity is based on mutation: sweet orange, sour orange, grapefruit, clementine, satsuma mandarin and some lemon trees (i.e., around 50% of the 1,100 accessions in the BRC). SSR markers are highly effective in detecting hybrid genotypes.
In addition, we detected several cultivars with identical genetic profiles (synonyms) and, conversely, several accessions of the same cultivar with different genetic profiles (homonyms). In both cases, phenotypic diversity was assessed using fruit characterization descriptors to confirm or invalidate the genetic interpretation.
The detection of a ‘Cleopatra’ mandarin accession with a low-acid pulp is an example of phenotypic diversity in the absence of SSR polymorphism.
We propose to create an international genetic database by promoting the use of a set of 10 common SSR markers and a common method for revealing and identifying them in order to characterize citrus collections in different countries.
This freely accessible international database would enable us to draw up an inventory of conserved genetic resources, but above all to guarantee a certain form of varietal authenticity between collections.
As part of the conservation of citrus genetic resources at the INRAE-Cirad Biological Resource Center (BRC) in San Giuliano, France, a genetic and phenotypic characterization procedure was set up.
Genetic characterization was carried out on 600 accessions, using 42 microsatellite markers (SSR) whose allelic profiles were revealed by denaturing capillary separation (ABI 300). SSR polymorphism is absent in species whose varietal diversity is based on mutation: sweet orange, sour orange, grapefruit, clementine, satsuma mandarin and some lemon trees (i.e., around 50% of the 1,100 accessions in the BRC). SSR markers are highly effective in detecting hybrid genotypes.
In addition, we detected several cultivars with identical genetic profiles (synonyms) and, conversely, several accessions of the same cultivar with different genetic profiles (homonyms). In both cases, phenotypic diversity was assessed using fruit characterization descriptors to confirm or invalidate the genetic interpretation.
The detection of a ‘Cleopatra’ mandarin accession with a low-acid pulp is an example of phenotypic diversity in the absence of SSR polymorphism.
We propose to create an international genetic database by promoting the use of a set of 10 common SSR markers and a common method for revealing and identifying them in order to characterize citrus collections in different countries.
This freely accessible international database would enable us to draw up an inventory of conserved genetic resources, but above all to guarantee a certain form of varietal authenticity between collections.
Publication
Authors
F. Luro, E. Marchi, G. Costantino, E. Bloquel, O. Pailly
Keywords
Citrus, germplasm collection, SSR, genetic database, genotyping, synonym, diversity
Groups involved
Online Articles (103)