RESUMO
BACKGROUND: Although potato as a crop is commercially grown from seed tubers, plants grown from tissue culture plantlets are often used in physiological studies including freezing tolerance determination. OBJECTIVE: This study aimed to examine the effects of the source of plants on freezing tolerance of potato plants at young developmental stages. MATERIALS AND METHODS: We compared freezing tolerance and contents of soluble proteins and sugars of Solanum tuberosum plants derived from tissue culture with those derived from tubers before and after cold acclimation. RESULTS: Tuber-derived plants showed significantly higher freezing tolerance than tissue-culture-derived plants after cold acclimation, although non-acclimated plants did not show any marked differences. Soluble protein contents were higher in tuber-derived plants regardless of cold acclimation. Sucrose content increased to a higher level in tuber-derived plants after cold acclimation. CONCLUSION: These results suggest that source of plant tissue can have a significant effect on the response of young potato plants to freezing stress and that the use of tissue culture plants in freezing tolerance studies may not accurately reflect the frost tolerance of commercially grown plants.