Abstract
Biochemical markers for cold-induced sweetening (CIS) resistance were tested for their stability over years and their use in selection of parents for crossing to achieve high selection efficiency in potato breeding programs.Two regulatory enzymes directly associated with reducing sugar (RS) accumulation during potato tubers cold storage were tested as a predictor for CIS resistance. These enzymes were studied in 33 potato clones from various breeding programs over four years. Clones with the presence of A-II isozymes of UDP-glucose pyrophosphorylase (UGPase) and low activity of vacuolar acid invertase (VAcInv) enzyme had increased resistance to cold-induced sweetening (CIS). Depending on the levels of these enzymes, clones were divided into class A, class B and class C. Clones categorized as class A had average RS of 0.73 mg per g FW after six months at 5.5°C storage. Class B and C had average RS of 1.15 and 3.80 mg per g FW respectively. The enzyme activity was closely associated with RS accumulation over long-term cold storage.The biochemical markers were found to be stable over the years. Repeated-measure analysis showed 75% chance of maintaining class from one year to the next and a 25% chance of switching, No clone switched between class A and class C, even across all four years. Application of these biochemical markers can identify clones with CIS resistance early in the selection process. Biochemical markers were used to select parents for crossing and six families were established. Results showed that with both parents from class A, 95% of their offspring had desirable glucose levels and chip color, which dropped to 52% when one parent was from class A and other from class B. These results suggest that two regulatory enzymes, i.e., UGPase and VAcInv, can be used as stable prognostic biochemical markers for CIS resistance for precise parent selection resulting in progenies with significantly higher percentage of clones with acceptable processing quality.
Highlights
In the USA about 61% of total potato production is used for processing into French fries, chips or granules
Results on biochemical markers are presented and Biochemical markers assisted potato breeding for cold-induced sweetening resistance discussed in terms of their association with reducing sugar accumulation, values as predictors of CIS resistance during cold storage and their use in precise parent selection for crossing
Compared to DNA-based markers, biochemical markers describe here 75% variation in tuber CIS resistance in this study. As these biochemical markers were found stable over the years, they can be used to select parents for cross to achieve a high frequency of clone with better CIS resistance
Summary
In the USA about 61% of total potato production is used for processing into French fries, chips or granules. Storage of potatoes at low temperatures, 2 to 4 ̊C, has several advantages including lower disease pressure, less shrinkage and water loss, reduced chemical use and longer storage and marketing window. These benefits are compromised at 2 to 4 ̊C by a physiological process commonly known as cold-induced-sweetening (CIS), whereby starch is degraded to produce excessive amount of RS, i.e., glucose (glc) and fructose (fru). Processing quality during storage is monitored through French fry color and RS level tests at regular intervals. French fry color and sugar tests cannot predict the tuber quality change during cold storage
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
