The Control and Branch Growth on Potato Tubers: I. ANATOMY OF BUDS IN RELATION TO DORMANCY AND CORRELATIVE INHIBITION

Abstract

A study was made of the morphology of potato buds during the dormant period and of the anatomy of dormant, growing, and correlatively inhibited buds. Lateral buds showed a progressive increase in development with increasing number of nodes measured basipetally, and some further development in association with second-growth of the tuber. In dormant buds, or buds which had not grown after the end of the rest period, the cytoplasm of cells in the meristematic dome stained only lightly with Heidenhain's iron-hematoxylin, whereas cells of buds which had grown had densely staining cytoplasm. The xylem vessels leading to dormant buds were filled with tannin-like substances for a short distance below the bud. Buds which had grown after the end of the rest period had both old obstructed xylem vessels and new open vessels. The end of the dormant period was not reflected in the internal bud anatomy unless buds also commenced to grow. Thus, while dormant buds had distinctive anatomical features, none of the structures appeared to be primarily associated with dormancy. Correlatively inhibited buds showed the features either of dormant or of growing buds depending on whether or not they had grown at the end of the dormant period.