MICROTUBER DORMANCY IN 3 POTATO CULTIVARS

Microtuber size, media growth regulators, incubation period, as well as bud maturity and endogenous abscisic acid content of microtubers were evaluated for their effects on length of dormant period of Kennebec, Russet Burbank and Superior microtubers. The dormant period of microtubers was found to be cultivar-specific and a significant correlation was observed between in vitro and in vivo dormant periods. Smaller microtubers (less than or equal to 250 mg) had longer dormant periods than did those greater than 250 mg. Dormant periods were unaffected by addition of coumarin or 2-(chloroethyl)trimethylammoniumchloride and 6-benzylaminopurine to the culture media or incubation period (28 and 56 days). Developmental age had no effect on individual buds ability to break dormancy and elongate. A positive correlation was observed between tissue levels of abscisic acid and microtuber dormant periods.