RANSGRESSIVE VARIABILITY OF MAIN SPIKE LENGTH IN F2 AND F3 POPULATIONS USING THE CYTOPLASM OF EARLY-MATURING SOFT WINTER WHEAT VARIETIES IN HYBRIDIZATION

The study aimed to determine transgressive variability in F1 and F2 populations created by crossing soft winter wheat varieties with different maturation rates. Materials and Methods. In 2019 and 2020, under field conditions at the research site of the Educational and Production Center of Bila Tserkva National Agrarian University, the studies were conducted on soft winter wheat varieties belonging to different maturity groups. Based on these, the following populations were created: Myronivska Early / Bila Tserkva Semidwarf, Myronivska Early / Kolchuga, Bila Tserkva Semidwarf / Kolchuga, Myronivska Early / Zolotokolosa, Myronivska Early / Chornyava, Bila Tserkva Semidwarf / Zolotokolosa, Bila Tserkva Semidwarf / Chornyava, Kolchuga / Chornyava, Myronivska Early / Antonivka, Myronivska Early / Yednist, Bila Tserkva Semidwarf / Antonivka, Bila Tserkva Semidwarf / Yednist, Bila Tserkva Semidwarf / Vіdrada, Kolchuga / Antonivka, Kolchuga / Yednist, Kolchuga / Vіdrada, Kolchuga / Stolychna, Myronivska Early / Vdala, Myronivska Early / Dobirna, and Bila Tserkva Semidwarf / Dobirna. The analysis methods included field, laboratory, comparative, and mathematical-statistical methods. Research Results. The meteorological conditions during the study years were characterized by contrasting temperature regimes and precipitation distribution, significantly influencing the formation of the main spike length in soft winter wheat and the degree of transgression. Positive transgressions in the main spike length were identified in 12 out of 20 studied third-generation populations, with a degree ranging from 4.8% (Bila Tserkva Semidwarf / Kolchuga) to 20.0% (Myronivska Early / Zolotokolosa and Kolchuga / Yednist), and a frequency of positive recombinants from 6.7% to 60.0%. Crossbreeding combinations with positive transgressive variability in both the second and third generations were identified: Myronivska Early / Bila Tserkva Semidwarf (Ts = 25.0%; 12.0%), Myronivska Early / Kolchuga (Ts = 14.3%; 7.6%), Myronivska Early / Zolotokolosa (Ts = 27.3%; 20.0%), Myronivska Early / Antonivka (Ts = 38.9%; 5.0%), Bila Tserkva Semidwarf / Vіdrada (Ts = 5.0%; Tc = 10.5%), Kolchuga / Antonivka (Ts = 23.8%; Tc = 8.6%), Kolchuga / Yednist (Ts = 42.9%; Tc = 20.0%), Kolchuga / Stolychna (Ts = 23.8%; Tc = 19.0%), Myronivska Early / Vdala (Ts = 33.3%; Tc = 12.0%), Myronivska Early / Dobirna (Ts = 15.8%; Tc = 10.0%), Bila Tserkva Semidwarf / Dobirna (Ts = 10.0%; Tc = 50.0%). Conclusions. It was noted that using early, mid-early, mid-maturing, and mid-late parental forms in hybridization promotes extensive formation in the second and third-generation populations of soft winter wheat, enabling the selection of long-spiked transgressive recombinants. The influence of annual conditions on the formation of main spike length and the manifestation of extreme maximum and minimum values in second and third-generation populations of soft winter wheat was established. Keywords: soft winter wheat, variety, main spike length, hybridization, transgressive variability.