biologia plantarum

Biologia plantarum 49:65-71, 2005 | DOI: 10.1007/s10535-005-5071-6

Development of freezing tolerance in different altitudinal ecotypes of Salix paraplesia

C. Li^1,*, N. Wu², S. Liu³

¹ Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, P.R. China

² Department of Biosciences, University of Helsinki, Helsinki, Finland

³ Institute of Forest Ecology and Environment, Chinese Academy of Forestry, Beijing, P.R. China

Salix paraplesia was used as an experimental model to investigate the effect of short day photoperiod (SD) and low temperature (LT) on development of freezing tolerance and on endogenous abscisic acid (ABA) contents. We characterized differences in SD and LT-induced cold acclimation in three ecotypes from different altitudes. The results demonstrated that cold acclimation could be triggered by exposing the plants to SD or LT alone, and that a combination of the different treatments had an additive effect on freezing tolerance in all ecotypes studied. However, the high altitudinal ecotype was more responsive to SD and LT than the low altitudinal ecotype. Development of freezing tolerance induced by SD and LT was accompanied by changes in ABA contents which were ecotype-dependent. Although the stem had higher initial freezing tolerance, the leaves developed freezing tolerance more quickly than the stem and thus leaves may provide an interesting experimental system for physiological and molecular studies of cold acclimation in woody plants.

Keywords: abscisic acid; cold acclimation; low temperature; short-day photoperiod

Subjects: abscisic acid (ABA); ecotypes, altitudinal, freezing; freezing, frost tolerance; growth analysis, plant development, biomass and yield enhancement; photon flux density; photoperiod, short-day; Salix paraplesia; short-day plant, cold acclimation; temperature, low, altitudinal ecotype; willow, altitudinal ecotypes

Received: September 2, 2003; Accepted: April 22, 2004; Published: March 1, 2005  Show citation