TITLE:
Sugar, Starch, and Proline in Peach Trees Exposed to Freezing Temperatures during Dehardening
AUTHORS:
Seok Kyu Yun, Haejin Bae, Kyung-Ho Chung, Ik Koo Yoon, Eun Young Nam, Jung Hyun Kwon, Ji Hae Jun
KEYWORDS:
Carbohydrate, Survival Rate, EC, Peach Cultivar
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.10,
August
28,
2014
ABSTRACT:
Freezing
temperatures cause different levels of freezing injury and change biochemical
components of trees. In this study, the range of survival temperature and
variation in electrolyte leakage, and in concentrations of sugar, starch, and
proline were determined in peach twigs (Jinmi, Changhowonhwangdo, and
Kawanakajima Hakuto) exposed to artificially controlled freezing temperature. Freezing
temperatures at which the plants were damaged by stress were found to be -21°C in Jan. and Feb., -18°C in Mar., and -6°C in Apr. Electrolyte leakage increased as
temperature decreased from -15°C to -24°C at each assessment time. Sugar gradually decreased after
the endodormancy period in the late part of winter, and sugar concentration
was overall lower in freezing temperature treatments, while starch increased as
a result of changing seasons from Jan. to Apr. The trend of proline
concentration was related to the survival rate of peach trees during winter. This
study suggests possible safe temperatures for survival and cultivation of peach
trees as well as identifying freezing temperature effects on internal
components of freeze-injured peach twigs.