Allele frequencies of Ppd-D1a, Ppd-B1a, and Ppd-B1c of photoperiodic sensitivity genes in spring bread wheat varieties (Triticum aestivum L.) of various origin

Aim. To identify and evaluate allele frequencies of Ppd-D1a, Ppd-B1a, Ppd-B1c and Ppd-1 of the genotypes of springbread wheat varieties from various climatic zones. Methods. DNA isolation, allele-specific PCR, electrophoresis inagarose and polyacrylamide gel, statistical analysis. Results. 137 varieties of spring bread wheat of various originwere detected to identify Ppd-1 genotypes of Ppd-D1a, Ppd-B1a and Ppd-B1c allele carriers. The results for the totalsampling of the varieties under investigation and the sampling of Asian varieties yielded six different Ppd-1 genotypesin each. As for samplings of other regions, there were from two (Mexico) to four (Europe, the USA, Canada, Ukraine)Ppd-1 genotypes. In the total sampling of varieties, there was a high incidence (20.5 %) of genotypes, dominant onlyin allele Ppd-D1a, varying from 0 (Russia) to 85.0 % (Mexico). The incidence of the genotypes with monogenicallydominant Ppd-B1a (7.3 %) or Ppd-B1c (5.1 %) in the total sampling, was considerably lower. These genotypes weremost common for the sampling of the varieties from the USA and Canada (25.0 and 16.7 % respectively). Digenicallydominant Ppd-D1a Ppd-B1a genotypes were found in the total sampling with relatively low incidence (7.3 %), andwere notable for the varieties from Asia (33.4 %), Mexico (15.0 %), Ukraine (13.1 %), and Europe (3.1 %). The digenically dominant genotype Ppd-D1a Ppd-B1с was found only in the Japanese variety Konosu-25. Gene Ppd-A1 waspresent in all the spring varieties under investigation in its recessive state. Conclusions. Out of three dominant allelesin the studied sampling, the highest incidence was noted for allele Ppd-D1a (28.5 %). All the varieties from Mexico,present in the set, carry this allele. At the same time, it was not found in any variety from Russia. Allele Ppd-B1a wasdetected in the varieties from all the regions with the incidence of 7.7 (Russia) – 44.4 % (Asia). Allele Ppd-B1c wassporadically present in the varieties from Russia, Ukraine, the USA, Japan, and Brazil, and its incidence in the totalsampling was insignificant (5.8 %). The varieties, identified by the allelic status of Ppd-1 genes, may be used as donorsfor selection and determination of the influence of alleles for each gene by the development rate and related economically valuable traits of bread wheat.