Cold De-acclimation Tolerance among Polish Accessions of Common Wheat and Triticale

AbstractCold de-acclimation is a phenomenon the frequency of which is expected to increase due to unstable winter temperatures predicted in the future [1] The aim of the present work was to screen for cold-de-acclimation tolerance the breeding materials of common wheat and triticale, and to find out whether this trait may be, at least partially, responsible for their winter survival.The experiment was performed during winter 2013/14 with 44 accessions of triticale and 78 accessions of wheat. Winter hardiness was studied in seven locations. The studies of freezing tolerance/de-acclimation were conducted at two experimental points where the plants were tested for the freezing tolerance before and after a warm spell during winter. Freezing tolerance on the cellular level was additionally assessed by means of chlorophyll fluorescence measurements after freezing.Our results indicated that the studied accessions of both species were highly variable in their tolerance to de-acclimation. Although no correlation between the freezing tolerance and de-acclimation tolerance was observed, all de-acclimation tolerant accessions were also highly freezing-tolerant. The maximum level of de-acclimation tolerance observed in triticale was higher than in wheat. It was also found that de-acclimation tolerance was responsible for different winter survival of triticale plants in one out of seven field locations, while in five locations no differences in winter survival were observed. In the case of common wheat, de-acclimation tolerance was not related to winter survival at any of three locations in which it varied between the studied materials.Similar observations, together with the studies of other risk factors for winter survival during future winters, will be continued for the next four winters to create models of future winter hardiness risk for wheat and triticale and to select plants with higher resistance to these factors.Founding: the Ministry of Agriculture and Rural Development (Poland) grant HOR hn 801-10/14