Effects of various growth regulators on the embryogenesis in a carrot cell suspension culture

Abstract

A high rate of embryo formation was observed in a suspension culture of a callus strain isolated from the petiole of a domestic carrot, Daucus carota cv. Kurodagosun, when the size of cell clusters of the culture was made uniform by sieving with nylon screens and when auxin was removed thoroughly from the culture medium. The embryogenesis was inhibited by exogenously supplied 2,4-dichlorophenoxyacetic acid (2,4-D) (> 10-9M) or indoleacetic acid (IAA) (> 10-10M) Zeatin promoted the embryogenesis at a concentration of 10-7M. In contrast, other cytokinins such as benzylaminopurine (BAP) or kinetin did not promote but instead inhibited embryogenesis. All the investigated combinations of zeatin with auxins, 2,4-D or indoleacetic acid, did not show promotion but inhibition. Gibberellin A3 (GA3) or abscisic acid (ABA) did not affect the number of embryos formed in the globular and early heart stages but caused a decrease of those in the heart and torpedo stages. © 1975.