Factors Influencing Embryogenesis in Carrot Cultures (Daucus carota L.)

Abstract

There is no doubt that isolated vacuolated carrot cells can de-differentiate and give rise to embryogenic clusters from which embryoids arise. However a study of the origins of embryogenic cells in culture suggests that the most frequent source is from groups of small meristematic cells liberated from the primary explant, and maintained as meristematic cells through numerous subcultures. Groups of vacuolated cells divide to give rise to callus nodules, which can undergo morphogenesis in a variety of ways. Transitions from one cell type to another are relatively infrequent, and cells generally divide to give rise to cells of similar type to the parent. The occurrence of a low proportion of embryogenic cells in an inoculum is sufficient to result in large numbers of embryoids when medium conditions are changed to favour their proliferation and development. The various routes by which plants can arise from carrot cultures are discussed.