Review on Breeding Potato (Solanum tuberosum L.) Genotypes for Processing Quality Traits

Potato (Solanum tuberosum L .) is a rich source of protein, energy, vitamins and minerals. Potato is in the family Solanaceae with chromosome numbers vary from diploid (2n = 2x = 24) to hexaploid (2n = 6x = 72). In Ethiopia, the major objectives of potato breeding was targeted at selection of clones for high yield, wide adaptability and resistance for late blight, hence processing qualitative traits were not the main targets in potato breeding program still near future. Therefore, the objective of this review article is to discuss breeding potato genotypes for desirable processing quality traits. Tuber shape is a syndrome of many characters that considers the length/width ratio for describing the overall shape; it varies from compressed/round to long. The yellow pigment in potato tuber flesh is caused by various carotenoids that may protect against cancer, cardiovascular disease, and macular eye degeneration. The genetics of morphological traits are Tuber flesh color, skin color and tuber shape and eye depth. To minimize waste, varieties with long tubers are preferred for French fries and varieties with round tubers are ideal for crisps. Eye depth is an important trait of tuber quality because deep eyes affect the appearance of tubers and add to the cost of peeling in processing factories. Tuber quality traits in potato are specific gravity, dry mater content, starch content, Glycolalkaloids and tuber size uniformity. Specific gravity of potatoes is commonly used by the potato processing industry as a tool for quick estimation of dry matter content, as both are highly correlated. Tuber dry matter content and specific gravity significantly influenced by the interaction effect of growing environment and cultivars. Processing quality usually has relatively low to moderately high heritability, depending on the progenitor materials. Therefore, multiple location tests over several years are often required in order to determine whether a clone has indeed a high processing quality.