Effect of different concentration of 2,4-D on somatic embryogenesis in some Iranian carrot genotypes

In respect to the ability of embryo production from somatic cells, somatic embryogenesis could be the preliminary step of artificial seed production. So at present research was conducted for identifying the most suitable genotype and hormonal combination for embryogenic callus as complete randomized design in three replications on 25 percent MS medium. First factor Iranian carrot genotype in 9 levels and second factor is hormonal combinations in 4 levels (control, 2, 4 and 6 mg.L-1 2,4-D). Plantlet was produced by in vitro seed culture and hypocotyle of those planlets was used for produce embryogenic callus. 12 weeks after explants culture, callogenesis percent, callus length and diameter, callus dry and fresh weight and also callus tissue type, color and embryogenesis situation was evaluated. Also, globular, heart and turpedo shape embryos were numerated. Results showed that maximum callogenesis (100 percent) was obtained in 99-26 (without plant growth regulator) and 99-31 (in 4 mg.L-1 2,4-D) genotypes. Embryogenic callus production was observed in 99-16, 99-27, 99-64 and 99-40 genotypes in present of 2 mg.L-1 2,4-D and in 99-56 ad 99-31 genotypes in present of 4 mg.L-1 2,4-D. 99-64 was produced maximum globular (13), heart (5.33) and torpedo (3.33) embryos. Genotype 99-64 and 2 mg.L-1 2,4-D are suitable for producing the maximum number of somatic embryo. In general Iranian carrot genotypes showed different responses to Callus Induction and embryogenesis.