Effect of Seed Treatment on Growth and Growth-substance Content of Dwarf French Beans (Phaseolus vulgaris)

The longer the seeds of dwarf French bean (Phaseolus vulgaris) were soaked in water before sowing, the smaller were the seedlings they produced. Soaking for 24 hours removed only little dry matter, but detectable amounts of a gibberellin and a betaine. The amounts of these two removed increased with increased time of soaking. Long soaking of seeds decreased the amounts of gibberelin and auxin in the cotyledons, and of gibberellin, auxin, and betaine in the primary leaves of seedlings. Aerating, cooling, or increasing the volume of water in which the seeds were soaked also retarded the growth of the seedlings, but did not affect the amount of growth substance removed from the seeds or contained in the cotyledons. The deleterious effect of soaking seeds was not alleviated by treating the seeds or seedlings with gibberellic acid or glycine betaine. Although larger seedlings were produced by heavy than by light seeds, their cotyledons and primary leaves contained similar concentrations of growth substances.