Differences between plant species in their ability to utilise substituted phenoxybutyric acids as a source of auxin for tissue culture growth

Abstract

Callus initiation and growth from leaf pieces of several Nicotiana species was examined in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D) or 2-methyl,4-chlorophenoxyacetic acid (MCPA) as auxins, and in the presence of the corresponding butyric acids 2,4-dichlorophenoxybutyric acid (2,4-DB) or 2-methyl,4-chlorophenoxybutyric acid (MCPB). The phenoxybutyric acids must be converted by β-oxidation to 2,4-D or MCPA within the plant to give an auxin response. Some species grew readily in the presence of the butyric acids but others did not. It is suggested that butyric acids should be useful as a selective screen in somatic hybridization work, and in mutagenesis studies.