The Canon of Potato Science: 41. Sprouting

摘要

Sprouting is the visible growth of shoot meristem tissue in the "eyes" of potato tubers which occurs after dormancy has ended. It is the major visible milestone in determining tuber physiological age. The earliest observable stage of sprouting, when only small white buds are visible, is often termed "pipping" or "peeping". Sprouts have multiple nodes, with meristematic tissue and leaf primordia present at each node as well as at the distal end. Since potato tubers are modified shoot tissue, the apical ("rose-end") eye is first to sprout, followed by sprouting at the lateral eyes as apical dominance diminishes. Potato sprouts are negatively geotropic and usually develop adventitious roots on the basal portions. Branching of the sprout occurs when apical dominance within the sprout is overcome, either after the sprout is sufficiently large, or following damage to the apex. Repeated damage to the apical ends of sprouts and branches can lead to excessive branching at the eye, forming a tightly-packed rosette of sprouts. Internal sprouts are normal sprouts which penetrate the originating tuber or an adjacent tuber due to close proximity, pile pressure or resetting.