Germination and Early Growth Responses of Marchantia Gemmae to Some Growth Regulators

Abstract

Germination and initial intercalary growth of gemmae were not influenced by 2,4-D, maleic acid hydrazide, gibberellic acid, or 2-furanacrylic acid (/P-2-furylacrylic acid) in concentrations up to 250 ppm. Gibberellic acid delayed rhizoid development, but maleic acid hydrazide had no effect. No difference in number of rhizoids was noted. Apical cell activity and cell elongation were generally suppressed. Internal differentiation did not occur in plants treated with 2,4-D and maleic hydrazide, and only localized areas were differentiated in enlarging plants under 2-furanacrylic acid. The results indicate an increasing sensitivity with age of the plant to both type and con- centration of the regulator. While relatively few bryophytes have been used in studies of the effects of growth regulators on plants, there is increasing evidence that different species display similar responses. It was thought that an investigation of the differentiation, size, and general appearance of cells of gemmalings grown in cultures containing varying concentrations of known growth substances might be of value in determining the mechanisms by which these effects are produced. Therefore, the objective of this study was to de- termine if certain growth regulators consistently affected gemma germination and development.