Media culture factors affecting somatic embryogenesis in Agave angustifolia Haw.

Abstract

A complete protocol of somatic embryogenesis involves induction of embryogenic callus, embryo development, embryo maturation, and their conversion or germination to form complete plants; in this sense judicious se- lection of nutrient medium, growth regulators, and physical culture environment is required. In this work, culture medium factors that influence somatic embryogenesis in Agave angustifolia were investigated. In an induction medium (IM) we evaluated the effect of three sucrose concentrations, three plant growth regulator (PGR) combinations, two groups of vitamins and two sources of amino acids. We observed that somatic embryos (SE) in medium containing 6% sucrose concentration grew vigorously, while those induced in medium with 8% sucrose were abnormally shaped and did not develop fully. In contrast, a higher sucrose concentration (10%) inhibited development of explants. Embryogenic callus cultured in IM containing 13.59μM 2,4-di- chlorophenoxyacetic acid (2,4-D) and 4.44 μM 6-benzyladenine (BA) only produced SE, while those explants assayed in IM with 11.34 μM abscisic acid (ABA) did not improve embryogenesis response. Phillips-Collins (L2) vitamins induced a higher number of SE (34 ± 0.4) than Murashige–Skoog (MS) vitamins (1.7 ± 0.7). High levels of amino acids (500 mg l−1 L-glutamine or casein hydrolysate) were not effective in promoting embryogenesis. Conversion frequency to plantlets ranged from 95 to 100% with 100% survival under ex vitro conditions.