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 spring bread wheat varieties from various climatic zones. Methods. DNA isolation, allele-specific PCR, electrophoresis in agarose and polyacrylamide gel, statistical analysis. Results. 137 varieties of spring bread wheat of various origin were detected to identify Ppd-1 genotypes of Ppd-D1a, Ppd-B1a and Ppd-B1c allele carriers. The results for the total sampling of the varieties under investigation and the sampling of Asian varieties yielded six different Ppd-1 genotypes in 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 only in allele Ppd-D1a, varying from 0 (Russia) to 85.0 % (Mexico). The incidence of the genotypes with monogenically dominant Ppd-B1a (7.3 %) or Ppd-B1c (5.1 %) in the total sampling, was considerably lower. These genotypes were most common for the sampling of the varieties from the USA and Canada (25.0 and 16.7 % respectively). Digenically dominant Ppd-D1a Ppd-B1a genotypes were found in the total sampling with relatively low incidence (7.3 %), and were notable for the varieties from Asia (33.4 %), Mexico (15.0 %), Ukraine (13.1 %), and Europe (3.1 %). The di genically dominant genotype Ppd-D1a Ppd-B1с was found only in the Japanese variety Konosu-25. Gene Ppd-A1 was present in all the spring varieties under investigation in its recessive state. Conclusions. Out of three dominant alleles in 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 was detected in the varieties from all the regions with the incidence of 7.7 (Russia) – 44.4 % (Asia). Allele Ppd-B1c was sporadically present in the varieties from Russia, Ukraine, the USA, Japan, and Brazil, and its incidence in the total sampling was insignificant (5.8 %). The varieties, identified by the allelic status of Ppd-1 genes, may be used as donors for selection and determination of the influence of alleles for each gene by the development rate and related economically valuable traits of bread wheat.