FACTORS AFFECTING REGENERATION OF THE HORSERADISH ROOT

Abstract

Over 15,000 small isolated pieces of the horseradish root (Cochlearia armoracia) were studied under controlled conditions. Buds were affected more than roots by temp. changes. Between 15[degree]C-25[degree]C the Q10 for bud initiation was 2.8, that for root initiation 1.6. The optimum temp. for root and bud initiation was 26[degree]C. Over a wide range of concs., naphthaleneacetic acid inhibited bud initiation and stimulated root initiation; high concs. of it could induce roots to form from any living tissue of the root. Several other organic and inorganic compounds, including various vitamins and other "active" substances, had little effect on either root or bud initiation. The initiation of roots and buds was confined to the root traces. The outer tissues of the root were responsible for root initiation; the inner tissues contained a factor that stimulated bud initiation. This factor moved only along the root trace and required intact cells for its transfer. Extracts of the inner tissues indicated that it is a chemical entity.