SOMATIC EMBRYOGENESIS AND PRODUCTION OF SYNTHETIC SEEDS IN ZIZIPHUS
Cotyledon, hypocotyl and epycotyl explants of Ziziphus mauritiana, Z. jujube and Z. spina-christi were cultured on Murashige and Skoog (MS) basal medium supplemented with 2,4-D, kinetin and N6-(2-isopentenyl) adenine (2iP). These explants after 2 weeks in darkness at 25°C followed by 4 weeks in 16 h light at 25°C produced embryogenic callus with very compact, pale yellow, nodular structures and/or pro-embryos. Proliferation and maintenance of embryogenic callus was on MS basal medium with 3 mg/L kinetin with a regular subculture every 15 days. Somatic embryo multiplication was achieved by separating the adventive somatic embryos one by one and subculture in hormone-free MS medium. Somatic embryo multiplication, maturation and germination occurred in the same hormone-free MS basal media. Vitrification of somatic embryos highly affected the plantlet regeneration. Partially desiccated embryogenic mass produced healthy somatic embryos, which germinated into healthy plantlets with roots. Synthetic seed formation was attempted by encapsulation of the somatic embryos in matrix comprise of different concentrations of sodium alginate. The synthetic seeds of Ziziphus were able to germinate on hormone-free MS basal media. Addition of 0.1 mg/L BA and 0.01 mg/L NAA enhanced the plant growth, elongation and rooting. Rooted plantlets subjected to photoautotrophic culture system for 30 days at controlled light, temperature and humidity survived 100% during greenhouse acclimatization. Field evaluation confirmed the clonal nature of the micropropagated Ziziphus plantlets. The micropropagated Ziziphus plants flowered and fruited faster than the seedling originated plants. Further studies on rate of conversion of somatic embryos in to plantlets are in progress for the commercial production.
Sudhersan, C., Jibimanuel, S. and Ashkanani, J. (2013). SOMATIC EMBRYOGENESIS AND PRODUCTION OF SYNTHETIC SEEDS IN ZIZIPHUS. Acta Hortic. 993, 83-90
tissue culture, embryo multiplication, vitrification control, acclimatization