Читать книгу Biotechnology of Fruit and Nut Crops - Группа авторов - Страница 83

Slow-growth storage conditions, including modifications of medium components and culture conditions, and synthetic seed technology for medium-term storage and cryopreservation involving dehydration- and vitrification-based one-step freezing for long-term preservation of Pistacia species could be utilized as complementary strategies. Pistachio microshoots survived slow growth storage for up to 18 months at 4°C and/or by using various photoperiods and light intensities together with inclusion of abscisic acid (ABA) (0.25–4 mg/l) or mannitol (2.5–40 mg/l) in the plant growth medium (Barghchi, 1986b). Somatic embryos and embryogenic cultures (Onay et al., 1996) and axillary buds (Ozden-Tokatli et al., 2009) have been encapsulated in Na-alginate as the gelling agent and CaCl₂·2H₂O as the complexing agents. Onay et al. (1996) reported that encapsulated somatic embryos could be conserved for up to 2 months at 4°C with 14% recovery. Akdemir et al. (2013) reported that ‘Atlı’ and ‘Siirt’ can be preserved as either microshoots or encapsulated shoot apices for up to 12 months at 4°C in darkness. Genetic stability of medium-term conserved mastic tree shoot cultures was evaluated by IRAP and AFLP analysis and genetic stability was reported (Koç et al., 2014).

Dehydration-based one-step freezing was developed as a cryopreservation method for seeds of pistachio, P. lentiscus and P. terebinthus (Ozden-Tokatli et al., 2007); 90% germination was achieved for ‘Bianca’ with 8 h desiccation in silica gel followed by immersion in liquid nitrogen, while 47% of P. lentiscus and 16% of P. terebinthus germinated after 15 min and 1 h dehydration, respectively. Vitrification and droplet-vitrification one-step freezing were used for cryostorage of in vitro ‘Siirt’ axillary buds (Ozden-Tokatli et al., 2009) and ‘Atlı’ shoot apices (Akdemir et al., 2013), respectively. Up to 11% viability was obtained by incubating ‘Siirt’ axillary buds in plant vitrification solution (PVS2, 30% glycerol, 15% ethylene glycol, 15% DMSO and 0.4 M sucrose) (Sakai et al., 1990) for 60 min at 0°C (Ozden-Tokatli et al., 2009), while 13.6% regrowth was achieved by incubating shoot apices of mature ‘Atlı’ for 150 min at 0°C followed by direct immersion in liquid nitrogen (Akdemir et al., 2013). Cryopreserved pistachio plantlets were assessed by RAPD analysis and genetic stability was affirmed (Akdemir et al., 2013).