Location: Vegetable Crops ResearchTitle: Potato development and skin set in fresh market red varieties
Submitted to: Wisconsin Potato and Vegetable Growers Associaiton Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/17/2015
Publication Date: 2/3/2015
Citation: Bethke, P.C., Busse, J.S. 2015. Potato development and skin set in fresh market red varieties. Wisconsin Potato and Vegetable Growers Associaiton Conference Proceedings. 28:81-82.
Technical Abstract: A bright, attractive, uniformly pigmented skin is critically important for fresh market red-skinned potatoes. We will summarize what is known about the potato skin development, with an emphasis on pigment accumulation and loss. We will provide some insight into what may be responsible for changes in skin color over time. Potato tubers develop from stolons that are covered by a single layer of epidermal cells. Epidermal cells serve many functions including mechanical protection and reduction of water loss. With tuber initiation and subsequent development, cell divisions occur in the epidermis and sub-epidermal tissues. This results in the formation of a periderm, or skin that assumes a protective role for the tuber. Collectively, the periderm is composed of the phelloderm, cork cambium (phellogen) and cork cells (phellem). It is the cells of the periderm, and especially the cork cells, that contain the water-soluble red pigments that give red-skinned tubers their attractive color. These pigments, various forms of anthocyanins, accumulate in specialized subcellular compartments within multiple cork cell layers of a good quality periderm. The loss of periderm color is not well understood. Skinning incurred during harvest degrades product appearance when wound-healing results in areas with no or little pigmentation. Genes that are required for pigment formation are strongly repressed in wound periderm, and this is the likely reason that healed wounds contain substantially less pigment than undamaged skin. A loss of skin color brightness and development of netting is commonly observed during storage. The reasons for this are incompletely known, but it may be that periderm cells lose pigment as they age or as outer cell layers die. The red color depends on the pigments being located in an acidic subcellular compartment. It is reasonable to speculate that red color is lost from cork cells as cells die since the cellular machinery required to produce an acidic environment is compromised.