PECULIARITIES OF INHERITANCE IN F1 AND TRANSGRESSIVE VARIABILITY IN F2 POPULATIONS OF GRAIN WEIGHT PER MAIN SPIKE IN CROSSES OF WINTER WHEAT OF DIFFERENT ECOTYPES

Abstract

The purpose – determining the nature of inheritance of grain weight from the main ear in F1 and establishing transgressive variability in F2 populations created by crossing soft winter wheat varieties of forest-steppe, steppe and western european ecotypes. Methods. In 2022–2023, 27 hybrids and F2 hybrid populations created by hybridisation of winter bread wheat varieties were studied in the experimental field of the research and production centre of Bila Tserkva NAU: Zorepad bilotserkivskyi (Zor. bts.), Kvitka poliv (Kv. poliv) – forest-steppe ecotype; Lastivka odeska (Last. od.), Znakhidka odeska (Znakh. od.) – steppe ecotype; Mulan, Fidelius – western european ecotype. Seeds of F1 and F2 populations were sown with a manual sowing machine according to the scheme ♀ (maternal form) – F1-2 – ♂ (male form). The biometric analysis of the studied material was carried out using an average sample of 25 plants in triplicate. The degree of phenotypic dominance of grain weight from the main ear was determined by the formula B. Griffing. The obtained data were grouped according to the classification of G. M. Beil, R. E. Atkins. The degree (Ts, %) and frequency (Tch, %) of positive transgressions were determined by the conventional method. Results. In the hybridisation of forest-steppe and steppe ecotypes, we found a positive correlation at the level of moderate correlation between the degree of phenotypic dominance and the degree of transgression (r = 0.313) and their frequency (r = 0.345). No close correlations were found when the Western European ecotype was involved in hybridisation. For example, a positive, weak correlation was found between the degree of phenotypic dominance and the degree of transgression (r = 0.063), and a positive correlation with the frequency of transgression with a change in sign (r = – 0.132). Conclusions.1. The inheritance of grain weight from the main ear of winter bread wheat in recurrent crosses of forest-steppe, steppe and western european ecotypes in most hybrids was positive superdominance (hp = 2.1–83.0) with modification of phenotypic dominance depending on the components of hybridisation. 2. In 18 out of 27 F2 populations, a positive degree (Тс = 0.3–40.0) was determined by the weight of grain from the main ear with the frequency of recombinants – Тч = 50.0–100.0 %. 3. The involvement of forest-steppe, steppe and western european ecotypes in hybridisation promotes the formation of F2 populations with the possibility of selecting economically valuable recombinants by grain weight per head, namely, by crossing the steppe ecotype with the forest-steppe ecotype: Lastivka odeska / Kvitka poliv (Ts = 40,8 %; Tch = 73,3 %), Znakhidka odeska / Zorepad bilotserkivskyi (Ts = 18.6%; Tch = 100.0%); steppe ecotype with steppe ecotype: Lastivka odeska / Znakhidka odeska (Ts = 25.5 %; Tch = 60.0 %); forest-steppe ecotype with western european ecotype: Kvitka poliv / Mulan (Ts = 29.6 %; Tch = 86.7 %); western european ecotype with forest-steppe ecotype: Fidelius / Kvitka poliv (Ts = 29.3 %; Tch = 73.3 %); steppe ecotype with western european ecotype: Znakhidka odeska / Mulan (Ts = 18.5 %; Tch = 83.3 %) and western european ecotype with steppe ecotype: Fidelius / Znakhidka odeska (Ts = 18.5 %; Tch = 83.3 %).