Do all lenticels on potato tubers form from stomata?

The limited literature on the lenticel features considered important in common scab disease infection highlights the need for a detailed study on the pathway of lenticel formation in potato tubers. A series of experiments were conducted in a hydroponic system to investigate the pattern of lenticel development during early stage of tuber formation. Detailed study of lenticel development on tubers revealed that two pathways of lenticels formation exist in potato tubers. Formation of lenticels from stomata, the commonly accepted pathway in the literature, occurred on all tubers, but when tubers expanded rapidly, lenticels were also formed directly from peridermal rupture. In most tubers, the majority of lenticels have formed from the second pathway. The initiation of lenticel formation in both pathways was shown to be via localised zones of increased cell division in the phellem layer, placing pressure on the outer cell layers and leading to rupture of the periderm. Continued cell division and expansion under the rupture site creates lenticular shaped structure of a mature lenticel.