Embryogenic tissue initiation and somatic embryogenesis in Fraser fir (Abies fraseir [Pursh] Poir.)

Abstract

Embryogenic suspensor mass (ESM) was established from immature seeds of Fraser fir. The initiation frequency of ESM was dependent on genotype, collection time, medium, and plant growth regulators (PGR) used. The ESM initiation potential was higher with seeds collected in late June (clone 16-273, 4.7%) or early July (clone 16-45, 2.2%) and decreased as the zygotic embryos matured. Excised proembryo stage of zygotic embryos was most appropriate to initiation of ESM. Most of the ESM arose from the seeds that were at the proembryo stage. From the four different culture media we compared, seven ESM lines were obtained: two lines from Murashige and Skoog (MS) medium with 4.4 μM benzyladenine (BA), one from Schenk and Hildebrandt (SH) medium with 4.5 μM thidiazuron (TDZ), and four from SH with 4.4 μM 6-benzyladenine. However, only one ESM line from clone 16-273 (June 24, SH+TDZ) could be proliferated in subsequent culture. Different concentrations of L-glutamine and casein hydrolysate (CH) in the medium were also compared for their effect on ESM proliferation. The highest proliferation rate (1.16-fold) was obtained from SH medium supplemented with 250 mg/L CH and 3.42 mM L-glutamine. In contrast, the lowest rate was noted when 1,000 mg/L CH plus 3.42 mM L-glutamine (0.17-fold) was added to the medium. As for somatic embryo maturation, the highest number of mature precotyledonary (100.1/g −1 FW ESM) or cotyledonary (64.3/g −1 FW ESM) somatic embryos was obtained on a medium containing 20 or 80 μM abscisic acid, 10% polyethyleneglycol, 4% maltose, and 0.3% gellan gum. For germination of the somatic embryos, the cotyledonary somatic embryos derived from maturation medium were transferred on halfstrength Litvay medium containing 0.3% gellan gum. The somatic plantlets were recovered from the germination medium and transferred to soils.

Conifer somatic embryogenesis – an efficient plant regeneration system for theoretical studies and mass propagation

“…Some examples of mature somatic embryo yield (number) calculated per 1 g of fresh weight: 64 for Abies fraseri (Kim et al 2009), 36 for Abies cephalonica (Krajňáková et al 2009), 187 in Pinus pinaster (Alvarez et al 2013), 321 in Pinus sylvestris (Aronen et al 2009), 269 for Picea glauca (Kong and Yeung 1995), 65 for Picea mariana (Tremblay and Tremblay 1995), 300-960 for hybrid of Larix (Lelu et al 1994). An undesirable phenomenon -loss of ability to produce mature somatic embryos -has been observed in embryogenic tissues of many species (Klimaszewska et al 2009).…”

The effect of culture medium formulation on Pinus nigra somatic embryogenesis

“…Many attempts have been done in order to improve the initiation of embryogenic tissues in conifers. The effort focused mainly on testing of nutrient medium com-position and plant growth regulators (Ewald et al 1995, Hazubska-Przybyl andBojarczuk 2008), carbon sources ( Salajova and Salaj 2005), vitamins (Pullman et al 2006), medium salt composition (Lelu et al 1994, Becwar et al 1990, Miguel et al 2004, Kim et al 2009, Krajňáková et al 2008, polyamines effect (Nakagawa et al 2011) as well as environmental (Vookova and Kormutak 2009) and genetic effects (Cheliak and Klim·aszewska 1991, Niskanen et al 2004, Yildirim et al 2006) have been studied.…”

Efficient and new method for Tectona grandis in vitro regeneration

“…The addition of adequate levels of TDZ cytokinin is known to increase shoot numbers in other trees, such as Pterocarpus marsupium (Husain et al 2007), Fraxinus americana (Palla and Pijut 2011), Prunus salicina (Canli and Tian 2009), Abies fraseir (Kim et al 2009), Melia azedarach (Vila et al 2007), Quercus rubra (Vengadesan and Pijut 2009), Pongamia pinnata (Sujatha and Hazra 2007), Acrocomia aculeate (Moura et al 2009), and Cinnamomum pauciflorum (Kong et al 2009). Finally, cytokinins play a central role during the cell cycle and influence numerous developmental processes, including the formation of shoot meristems, demonstrating their function beyond maintaining the cell cycle (Werner et al 2001).…”