The Effects of 2,4,6-Trichlorophenoxyacetic Acid on Embryogenesis in Wild Carrot Tissue Cultures

Adventive embryogenesis in wild carrot is enhanced by the lowering of the effective auxin concentration either by removal from the medium or by the addition of 2,4,6-T (2,4,6-trichlorophenoxyacetic acid) or both. Growth is similar in undifferentiated and differentiated tissue until the embryos begin to elongate; the elongation is slower in the presence of 2,4,6-T and a greater homogeneity of developmental stages occurs. Also, root hairs do not form in the presence of 2,4,6-T. Aerobic respiration is stimulated by 2,4,6-T and a synergistic effect with DNP also occurs. In addition, DNP exerts a greater effect on older tissue than on younger tissue.