Justo E., Elisirio P., Jacquemond Camille, Leitãoa J..
1999. Variety purity assessment of fifteen citrus rootstocks by isozymes prior to field trial implementation.
In : 5th world congress of the International Society of Citrus Nurserymen. Proceedings of the congress = [Cinquième congrès mondial de la Société Internationale des Pépiniéristes d'Agrumes. Actes du congrès]. Aubert B. (ed.)
Autre titre : Vérification, par la technique des isozymes, de la pureté variétale de quinze porte-greffes d'agrumes, en préalable à une expérimentation en champ
Résumé : Introduction. Citrus rootstocks are usually propagated commercially by seed because facultative apomixis through nucellar embryony favors high levels of genetic uniformity. In each seed, one zygotic embryo usually coexists with several somatic embryos of nucellar origin. Dependent on the genotype and environment, the probability of development of zygotic embryos determines the rate of apomixis characteristic of each rootstock cultivar. Commercial varieties grafted on zygotic rootstocks would show lower growth and yield than those on nucellar individuals of the same variety. Selection against zygotic rootstocks is partially accomplished in nurseries by routinely discarding off-type seedlings after visual evaluation. However, for comparative field trials, seedlings need to be more accurately evaluated and individuals of sexual origin rigorously eliminated. Isozyme analysis readily distinguishes zygotic and somatic seedlings. Materials and methods. Forty plants from each of 15 rootstock cultivars to be assayed under Algarve agricultural conditions underwent to isozyme analysis. Extracts for analysis were obtained by homogenizing leaf pieces in liquid nitrogen and resuspending the homogenate in an appropriate buffer. After starch gel electrophoresis of the leaf extracts, five isozyme systems were revealed : Pgi, Pgm, Idh, Mdh and Got. Results and discussion. Several plants, identified as originating from self- pollination or cross-pollination, were discarded. For the rootstocks analysed, apomixis rates varied from 88% to 100%. Morphological traits, as plant height or stem diameter, of zygotics and nucellar seedlings showed no significant difference.
Mots-clés Agrovoc : Citrus, isoenzyme, essai de variété, sélection, porte greffe, électrophorèse, apomixie, anatomie végétale, lignée pure
Mots-clés géographiques Agrovoc : Portugal
Mots-clés complémentaires : Criblage variétal
Classification Agris : F30 - Génétique et amélioration des plantes
Auteurs et affiliations
- Justo E.
- Elisirio P.
- Jacquemond Camille
- Leitãoa J.
Source : Cirad - Agritrop (https://agritrop.cirad.fr/391249/)
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