Oak somatic and gametic embryos maturation is affected by charcoal and specific aminoacids mixture

Abstract

Abstract• Development of both somatic and gametic embryogenesis has many applications in clonal forestry and genetic improvement, for instance as mass-propagation of genetically improved plants and production of pure lines through doubled-haploid plant regeneration from gametic embryos.• The goal of this work was to improve growth, maturation and plantlet regeneration of cork oak (Quercus suber L.) embryos from both somatic and gametic origin.• Activated charcoal promoted a significant increase in growth in terms of relative size and weight of both somatic and doubled-haploid embryos, as well as a more efficient control of secondary somatic embryogenesis during development. A significant interaction was also observed with amino acid nutrition. While some amino acids (i.e., glutamine, arginine or asparagine) did not show significant differences with the controls, a mixture of these three amino acids or gamma amino butyric acid stimulated embryo growth. The highest survival rate during acclimation of plantlets from both somatic and doubled-haploid origin was obtained when the embryos had been previously cultured on basal medium with 3% sucrose and 1% activated charcoal for two months at 4 • C and germinated on medium supplemented with 6-benzylaminopurine and indole-3-butyric acid.• We obtained more than 900 cork oak plantlets acclimated from several embryogenic lines, with a high survival rate, demonstrating that this methodology is applicable for large scale plantlet production. We also report the first regeneration of doubled-haploid plantlets in cork oak. • Le développement des deux embryogenèses gamétique et somatique a de nombreuses applications dans la foresterie clonale et l'amélioration génétique, par exemple en tant que propagation en masse de plants génétiquement améliorés et la production de lignées pures par régénération de plants haploïdes doublés d'embryons gamétiques. Mots-clés• L'objectif de ce travail était d'améliorer la croissance, la maturation et la régénération des plantules des embryons de chêne-liège (Quercus suber L.) des deux origines gamétique et somatique.• Le charbon actif a favorisé une augmentation significative de la croissance en termes de taille et de poids des embryons haploïdes doublés et somatiques, ainsi qu'un contrôle plus efficace de l'embryogenèse somatique secondaire au cours du développement. Une interaction significative a également été observée avec la nutrition aminoacide. Alors que certains acides aminés (c'est-à-dire, la glutamine, l'arginine ou l'asparagine) ne montrent pas de différences significatives avec les témoins, un mélange de ces trois acides aminés ou l'acide butyrique amino gamma a stimulé la croissance de l'embryon. Le taux de survie le plus élevé au cours de l'acclimatation des plantules d'origine à la fois somatique et haploïde doublé, a été obtenu lorsque les embryons ont été auparavant cultivés sur milieu de base à 3 % de saccharose et de 1 % de charbon actif pendant deux mois à 4 • C et ont germé sur un milieu complété par la 6-benzylaminopurine et ...

Improved secondary embryo production in Quercus alba and Q. rubra by activated charcoal, silver thiosulphate and sucrose: influence of embryogenic explant used for subculture

“…Charcoal is involved in the differentiation of somatic embryos, especially promoting maturation of cotyledon-shaped embryos and later germination (Merkle et al 1995). In other Quercus species, charcoal (1 %) was used for promoting maturation of 3-4 mm cotyledonarystage embryos of cork oak (Hernández et al 2009;Pintos et al 2010) and holm oak (Barra- Jiménez et al 2014) with a significant increase in both embryo size and fresh weight, as well as stopping repetitive embryogenesis during maturation. However, results of the present study indicate that charcoal may be used prior to the embryo maturation step, since small embryogenic structures subcultured in proliferation medium containing AC produce well-developed and singularised SSEs.…”

Application of biotechnological tools to Quercus improvement

“…The application of a 2-month cold period as a pre-germination treatment stimulated embryo germination and conversion in material from Q. suber of immature zygote origin (Fernández-Guijarro et al 1995;García-Martín et al 2001;González-Benito et al 2002a) and Q. ilex (Mauri and Manzanera 2004), as well as in embryogenic lines from Q. suber of mature tree origin (Hernández et al 2003b). Similarly, the application of activated charcoal and a mixture of glutamine, arginine, and asparagine coupled with cold storage at 4°C for 2 months had a favorable effect on plantlet conversion in cork oak (Pintos et al 2010). In the embryogenic system derived from immature cotyledons of Q. rubra, germination was performed by desiccation for 3 days followed by cold storage for 8 weeks (Vengadesan and Pijut 2009).…”

Embryogenesis in Oak species. A review

“…These plantlets were acclimated in successive steps in the greenhouse and in the nursery. The high survival rate obtained, 78% (Pintos et al, 2010), proved that this methodology is applicable for large scale plantlet production. In the second year of nursery, the plantlets were transferred to 2 l pots with peat: vermiculite (3:1).…”