DIRECT AND INDIRECT SOMATIC EMBRYOGENESIS IN Coffea arabica var. Colombia

Abstract

Mexico is one of the top ten coffee producers in the world; however, the current state of its plantations faces genetic and phytosanitary
problems that require for coffee plantations to be renewed or repopulated with high quality plants. Tissue culture by micropropagation could help meet this requirement. The aim of this study was to establish culture conditions to induce somatic embryogenesis in Coffea arabica Colombia variety from leaf tissues. Leaf segments were cultured for 0, 3, 5, 8 or 10 days on media containing Yasuda or Murashige and Skoog salts (MS), 1.12 mg L^-1 6-benzylaminopurine (BAP), 0.5 mg L^-1 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.6 mM sorbitol. The culture medium containing the Yasuda salts, 1.12 mg L^-1 BAP and 0.6 mM sorbitol promoted the formation of embryos without a callus phase (direct embryogenesis). The medium composed of MS salts, 0.6 mM sorbitol, 1.12 mg L^-1 BAP, and 0.5 mg L^-1 2.4-D acid induced indirect somatic embryogenesis in explants. The percentage of explants that formed embryos was higher in direct embryogenesis (77.8) compared to indirect embryogenesis (55); the number of embryos per explant formed by indirect embryogenesis (153.2) was significantly higher than those generated by direct embryogenesis (10.3). The culture conditions established in this study allowed the formation of somatic embryos in Colombia variety.