Tuber shape

Many genetic studies in potato have focused on disease resistance. A summary of disease resistance genes and quantitative trait loci in potato has recently been published (Celebi-Toprak et al., 2005b). In addition, major quantitative trait loci have been identified for tuber dormancy (chromosome II), tuber eye depth (chromosome X), flesh color (chromosome IV), tuber shape (chromosome II) and uniformity of tuber shape (chromosome III) (Sliwka et al., 2008). 

Sliwka, J., Wasilewicz-Flis, I., Jakuczun, H., Gebhardt, C. (2008). Tagging quantitative trait loci for dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in diploid potato originated from six Solanum species. Plant Breeding, 127, 49-55. 

Squeezing a cut tuber produces a pale creamy, cheese-like ooze. Later, the discoloration becomes a more distinct brown and the necrosis can extend into the surrounding tissue. In advanced stages the bacterium can ooze from the heel end and eyes. This may result in reddish-brown, slightly sunken, and star-shaped lesions on the skin from which bacteria may ooze, causing soil particles to adhere. Yield loss may reach 50%. 

Love, S. L., Werner, B. K., Pavek, J. J. (1997). Seleetion for individual traits in the early generations of potato breeding program dedieated to producing cultivars with tubers having long shape and russet skin. American Potato Journal, 74,199-213. 

The tuber samples should be selected at random and be representative of the entire batch in question. The samples should be evaluated for specific gravity and graded for size and absence of external and internal defects. A sub-sample should be Ified and if the fry color is not satisfactory, a reducing sugar evaluation should be made and the strategies for storage and end use followed as recommended above. The appearance and size of tubers are important to the user, and cleaning, uniformity of shape and size, depth of eyes, flesh color, and peel are very important in terms of... 

Most clones have tubers with an irregular surface. Spindle-shaped tubers generally have the smoothest surface (Pas ko, 1973). An irregular surface is undesirable in that it makes preparation for cooking more difficult. 

Autol05.62G.2 — French origin. White tubers, ovoid (oblong) shaped. Early maturing. Maintained by Institut National de la Recherches Agronomique (INRA), UMR-DGPC, Montpellier, France (INRA MPHE001373) limited immediate availability. 

Blanc precoce [Early White] — French origin. Short-stemmed plants (1.5 to 2.0m), with small leaves. White tubers, short pear shaped with irregular surface. Early maturing. Synonymous with D19 breeding/research clone. Barloy, 1988 Barloy and Le Pierres, 1988 De Mastro, 1988 (tubers, 71.6 t/ha, 20.6 t DM/ha) Gabini, 1988 Mesken, 1988 Mimiola, 1988 Pas ko, 1973, 1974 Varlamova et al., 1996. 

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