Genetic variability analyses of the somatic embryogenesis induction process in Olea spp. using nuclear microsatellites

• Published in: Trees (Berlin, West) Vol. 23; no. 1; pp. 29 - 36
• Main Authors: Lopes, Tina, Capelo, Ana, Brito, Gina, Loureiro, João, Santos, Conceição
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.02.2009; Springer-Verlag; Springer Nature B.V
• Subjects: adults; Agriculture; Archipelagoes; Biomedical and Life Sciences; callus; Developmental stages; Economic importance; Embryonic growth stage; explants; Forestry; Fruit trees; genotype; Growth regulators; Indigenous species; indole butyric acid; Leaves; Life Sciences; loci; Mediterranean region; micropropagation; microsatellite repeats; mutation; Olea europaea; olives; Original Paper; petioles; Plant Anatomy/Development; Plant Pathology; Plant Physiology; Plant Sciences; somaclonal variation; somatic embryogenesis; somatic embryos; trees; zeatin; Mediterranean region; Microsatellites; In vitro culture; Somaclonal variation; Somatic embryogenesis
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s00468-008-0251-6

The crop species Olea europaea L. (olive tree) is of great economic importance in the Mediterranean region. Hence, many efforts have been done in the last decades to propagate this commercially valuable species by in vitro methods. On the other hand, the lesser known Olea maderensis (Lowe) Rivas Mart. & Del Arco which is a native species of the Madeira Archipelago has only been the subject of micropropagation from nodal stem cuttings. Therefore, in this work we analysed the stability of ten nuclear simple sequence repeat (SSR) markers at successive stages of the somatic embryogenesis process in two adult trees belonging to these two species from the Madeira Archipelago. For the induction of somatic embryogenesis, petiole and leaf explants were cultivated on solid Murashige and Skoog medium (MS) with 12.25 μM indole-3-butyric acid (IBA) and 4.56 μM of zeatin, in the dark. After 3 months, different callus tissues (non-embryogenic, pre-embryogenic and embryogenic) developed from leaf explants and petioles were later transferred to MS medium without growth regulators in the dark. All ten SSR markers were able to distinguish between species. However, no mutations were found at the SSR loci at any of the successive developmental stages from PEMs (pre-embryogenic masses) to somatic embryos. This genetic uniformity was observed within material derived from each genotype/species and its respective donor plant. Therefore, we conclude that the genomic integrities of both O. europaea and O. maderensis were maintained throughout the stages of the embryogenic processes in study suggesting the absence of somaclonal variation.