The term "dormancy" is frequently used to describe a potato's storability. The dormancy value, often known as the length of dormancy, indicates how long the potato will be stored before sprouting. The growing season or pre-harvest conditions can affect dormancy length along with post-harvest conditions such as temperature and light which can influence dormancy length. The beginning of dormancy break begins before visible sprout development. The physiological processes related to dormancy and subsequent sprout formation are still being studied by researchers.
There are many factors contributing to potato tuber dormancy including genetic background, tuber maturity, plant hormones, environmental conditions during tuber growth, and storage conditions. The five key plant hormones are thought to be involved in the process. Dormancy induction is aided by abscisic acid and ethylene, dormancy break is aided by cytokinins, and sprout growth is aided by gibberellins and auxins. A QTL analysis demonstrates that some genes, TG234, TG66, and TG443 have some effects on potato dormancy (Van den et al, 1996). In addition, a pivotal gene, StSN2, related to dormancy, which maintains tuber dormancy suggested by Mengsheng Deng et al, 2021. Over expression of StSN2 gene show a high dormancy period compared to wild-type potato.
Knowledge on dormancy length provides information on selecting varieties for short to long-term storage, planning for proper timing of sprout inhibition products, and marketing of the potatoes. For process and fresh market potatoes, detrimental quality concerns develop once sprouting begins such as changes in carbohydrate status, increase in respiration rate, additional weight loss, and storage management issues.
After harvest, potatoes are held in cold storage (usually at 4°C) in Bangladesh, like in many other potato-producing nations, to ensure a year-round supply to industry and consumers. Despite the many benefits of cold storage, tubers accrue a significant quantity of sucrose (Suc), which is then transformed into glucose (Glu) and fructose (Fru) in a process known as cold-induced sweetening (CIS). While processing like frying at high temperature, these potatoes lead to dark-brown-colored chips as a result of Maillard reaction between the accumulated reducing sugars and free amino acids (arginine) and thus these darkened chips and fries are unacceptable to consumers. As CIS remains one of the serious hurdles of the potato processing industry, developing CIS-resistant genotypes is one of the frontal areas of research on potato quality all over the world. To conclude researchers need to pay attention to the regulation of potato dormancy for processing potatoes.
- J H van den Berg, E E Ewing, R L Plaisted, S McMurry, M W Boierabale, QTL analysis of potato tuber dormancy, Theor Appl Genet.1996 Aug; 93(3):317-24
- M Deng, J Peng, J Zhang, S Ran, C Cai, L Yu, S Ni, X Huang, L Li, X Wang, The cysteine-rich peptide Snakin-2 negatively regulates tubers sprouting through modulating Lignin biosynthesis and H2O2 accumulation in potato, Int. J. Mol. Sci. 2021, 22, 2287.
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