Frost Tolerance in Winter Wheat Genotypes Evaluated in Aral Sea Cold Zone in Central Asia.

Frost is an important constraint to winter wheat cultivation in Aral Sea zone of Central Asia encompassing parts of Uzbekistan, Turkmenistan and Kazakhstan. There is a need to identify frost tolerant improved varieties of winter wheat to increase productivity, and bring additional area under wheat cultivation to improve food security. In 2013, International Center for Agricultural Research in the Dry Areas (ICARDA) initiated CGIAR Research Program for Dryland Systems in the Aral Sea zone. One activity included identification of improved genotypes of winter wheat with frost tolerance. Three field experiments were conducted using more than 300 experimental lines and released cultivars in the Aral Sea Action Site in Karakalpakstan, Uzbekistan. In the first experiment, 170 advanced breeding lines were evaluated. To determine the effect of seeding depth on frost injury, 150 genotypes were planted at 2 and 4 cm depths in the second experiment. The third experiment comprised 14 genotypes that had been selected for frost tolerance in 2013, and one local cultivar (‘Krasnodar-99’). The lowest temperature recorded during winter wheat cycle was -25˚C in February.  Snow was removed from the plots to create frost occurrence. Seedling counts were made before and after winter to determine percent survival. Fifty four and 65% of the genotypes showed more than 80% winter survival in the first and second experiment, respectively. Overall, the seeding depth at 4 cm resulted in higher (71%) winter survival than that of 2 cm (41%). All of the 14 genotypes that were frost tolerant in 2013 remained tolerant in 2014 as well. A group of 39 farmers and other stakeholders evaluated the frost tolerant lines for agronomic traits and selected superior genotypes compared to Krasnodar-99. The results of this study have open possibilities in the identification of superior frost tolerant winter wheat genotypes for many frost-prone regions.