Study of vernalization requirement and photoperiod sensitivity in winter wheat varieties of Myronivka breeding in the conditions of the central forest-steppe of Ukraine

Background. The vernalization requirement and photoperiodic sensitivity are significant indicators as they determine the adaptability of plants to environmental conditions. The aim of the study was to characterize modern winter wheat genotypes by genetic systems that determine vernalization processes. Materials and Methods. The winter wheat varieties of Myronivka breeding, such as Vezha Myronivska, Avrora Myronivska, MIP Yuvileina, MIP Lada, MIP Fortuna, MIP Darunok, MIP Nika, MIP Roksolana, MIP Feieriia, MIP Vidznaka, and MIP Lakomka, were studied. The vernalization requirement duration and photoperiodic sensitivity of winter wheat varieties were determined according to the methodological recommendations (Demydov et al., 2019). Five winter bread wheat varieties, MIP Darunok, MIP Roksolana, MIP Nika, MIP Feieriia and MIP Vidznaka were crossed on incomplete diallele scheme with three near-isogenic lines derived from Erythrospermum 604 with different genotypes for the Vrd gene system 1) Vrd1Vrd1vrd2vrd2, 2) vrd1vrd1Vrd2Vrd2, and 3) vrd1vrd1vrd2vrd2. Hybridological analysis was performed in F2 populations by the comparison of the fact segregation of the plant phenotypes’ number with theoretically expected using χ2 criterion. Results and Discussion. The Vezha Myronivska, Avrora Myronivska, MIP Yuvileina, MIP Nika and MIP Roksolana varieties demonstrated low photoperiod sensitivity; the MIP Lada, MIP Fortuna, MIP Darunok, MIP Feieriia and MIP Vіdznaка varieties showed medium photoperiod sensitivity; the MIP Lakomka variety was characterized by high photoperiod sensitivity. The Vezha Myronivska, MIP Yuvileina, MIP Fortuna, MIP Nika, MIP Roksolana, MIP Feieriia, MIP Vіdznaка and MIP Lakomka varieties required vernalization duration for 30 days, whereas varieties Avrora Myronivska, MIP Lada and MIP Darunok for 40 days. The results of the hybridological analysis indicate the pre­sence of the dominant allele Vrd1 in the MIP Darunok and MIP Roksolana varieties, which contributes to shortening the vernalization duration. In the MIP Nika variety, the vernalization requirement duration is controlled by the dominant allele Vrd2, while in the varieties MIP Feieriia and MIP Vidznaka, it is controlled by two dominant alleles of Vrd1 and Vrd2 genes. Conclusions. The obtained results indicate the possibility of recombining different levels of photoperiodic sensitivity and vernalization requirement duration in the winter wheat genotype through breeding and developing varieties with their optimal combination for specific ecological conditions.