Establishment and optimization of callus-to-plant regeneration system using mature and immature embryos of maize (Zea mays)

Two experiments were conducted to develop an efficient maize regeneration system using mature and immature embryos of four maize elite lines (Agaiti-85, Golden, Soneri and Sultan). The comparative studies revealed that all maize lines were responsive to callus and plant regeneration from mature and immature embryos. The culture medium Chu's N6 was used in both experiments. Immature embryos efficiently produced callus and regenerated plants therefore, when cultured on medium supplemented with 2,4-D, kinetin, 6-BAP and IBA at concentrations of 2 mL L^-1, 0.2, 0.2 and 0.3 g L^-1, respectively. However, callus-to-plant regeneration system for mature embryos required these growth regulators at higher concentrations (5 mL L^-1, 0.4 g L^-1, 0.5 g L^-1 and 0.6 g L-1, respectively). The regeneration frequencies ranged from 40 to 75% using immature embryos, compared to 55 to 80% from immature embryos of all elite lines of maize under study.