Changes in Allele Frequencies at Storage Protein Loci of Winter Common Wheat under Climate Change

Abstract

Allele frequencies at the storage protein loci Gli-A1, Gli-B1, Gli-D1, Glu-A1, Glu-B1, Glu-D1, and Gli-A3, as well as the population structure, were studied in groups of winter common wheat cultivars developed in different periods of time in two soil and climate zones: the Forest-Steppe of Ukraine (at the Myronivka Remeslo Institute of Wheat (MIW)) and the Steppe of Ukraine (at the Plant Breeding and Genetics Institute (PBGI)), a total of 275 cultivars. The cultivars were grouped based on registration time: before 1996 (period 1), in 1996–2010 (period 2), and after 2010 (period 3). Differences in average annual temperature in the periods of development of these cultivars amounted 0.6 and 0.7°C between periods 1 and 2, and as high as 0.9 and 1.0°C between periods 2 and 3 for the Forest-Steppe and Steppe zones, respectively. In the groups of winter wheat cultivars of both MIW and PBGI developed after 2010, specific sets of predominant alleles were basically retained. At the same time, there was a clear relationship between changes in frequencies of certain alleles in cultivar groups and annual temperature changes in the locations where selection of genotypes (future cultivars) had taken place during breeding. The most prominent changes in allele frequencies were revealed for the cultivars developed in the Steppe of Ukraine: for the PBGI cultivars such temporal changes were detected for 10 alleles at 4 loci. Probably this is due to the fact that in the Steppe zone the annual temperature has reached the high absolute value, and new coadaptive gene associations are being formed and selected during breeding. The increased contribution of wheat germplasm derived from regions with higher temperature to winter common wheat breeding in the Steppe zone might be expected.