Abstract
The in vitro germination of radish pollen was studied utilizing various media. The results are as follows:
1. In a basal medium containing 50 mg•liter-1 boric acid, 100 mg•liter-1 CaCl2, and differ-ing concentrations of sucrose and a gel forming agent, the medium containing 15% sucrose and 0.2% gelrite yielded the highest percentage of pollen germination.
2. Germination rate was improved by imbedding the stigma, style, ovary and ovule in a medium; the addition of a young stigmas which was collected two days before anthesis gave the best results of any treatment.
3. Germination was also promoted by substance (s) extracted from the tissues with methanol or ethylacetate; substances which partitioned into the ethylacetate layer were more active than those which remained in the aqueous layer. Substances which partitioned into the neutral frac-tion were more active than those in the acidic fraction; the basic fraction evoked the least amount of activity.
4. Glycocholic and cholic acids and steroids were found to promote germination of radish pollen in vitro.
