Ammonium Requirement for Embryogenesis in vitro

Abstract

PREVIOUS work on tissue cultures of the wild carrot has shown that the embryogenesis which occurs in such cultures is not fundamentally different from the same process in the ovule^1,2. It has also been shown that undifferentiated pro-embryos, sieved from callus, will continue to grow in a disorganized non-polar fashion if they are exposed to a concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) which is higher than 0.1 mg/1. (ref. 3). Lowering the 2,4-D concentration permits histological differentiation and polarized growth to occur. It is thus possible to establish a crude control over the process of embryogenesis by suitable alterations of the 2,4-D concentration. While this technique has provided an experimental system in which the simultaneous development of numerous embryos can be examined, it has provided no information on the morphogenetic factors which initially cause cultured cells to behave as zygotes.