Spike performance transgression degree and frequency in F2 winter bread wheat hybrids
Authors: Chernobai Yu. O. , Riabchun V. K. 
Published: August 2023

Purpose and Objectives. To analyze the spike performance transgression degree and frequency in F2 winter bread wheat hybrids.
Materials and Methods. The study was carried out in the Laboratory of Genetic Resources of Cereals of the Plant Production Institute named after V.Ya. Yuriev of NAAS in 2019–2021. Thirty 30 F2 hybrids from diallel crossings and 20 F2 hybrids from tester crossings were investigated. The experiments were carried out in accordance with the requirements for field experiments in breeding. F2 hybrids and their parents were sown with a manual single-row planter within the optimal timeframe. The row length was 1 m; the interrow distance was 20 cm; the depth was 4–6 cm; wheat was sown after bare fallow. Twenty seeds per row were sown. Data were statistically processed, as B.A. Dospekhov recommended. The transgression degrees and frequencies for quantitative traits were determined by the formulae proposed by H.S. Voskresenskaya and V.I. Shpota.
Results and Discussion. Analyzing the F2 hybrids from diallel crossings, positive transgressions of the “pike length” trait were found in all the analyzed hybrids. The highest degree of transgressions was recorded for Ladyzhynka / Dyvo (Td = 18.0%) and Vodohrai Bilotserkivskyi / Ladyzhynka (Td = 12.1%); the highest frequency of transgressions of this trait was observed in Ladyzhynka / Dyvo (Tf = 89.7%) and Khvala / Dyvo (Tf = 85.0%). The maximum degree of transgressions for the kernel number per spike was detected in Vodohrai Bilotserkivskyi / Khvala (Td = 12.9%), and the maximum frequency of transgressions of this trait was noted in Kubok / Ladyzhynka (Tf = 50.7%). Kubok / Dyvo was selected due to degree and frequency of spike weight transgressions (Td = 25.7%; Tf = 54.3%). The maximum advantage over the better parent in terms of the spikelet number per spike and the maximum frequency of transgressions of this trait were noted in Vodohrai Bilotserkivskyi / Khvala (Td = 18.6%; Tf = 88.7%). The maximum advantage over the better parent in terms of kernel weight per spike was detected in Kubok / Dyvo (Td = 27.7%); but the highest frequency of transgressions of this trait was recorded for Kubok / Korovaina (Tf = 54.3%). As to thousand kernel transgression degree and frequency, Kubok / Dyvo was distinguished (Td = 12.4%; Tf = 82.7%).
Analyzing the F2 hybrids from tester crossings, the Khvala / Kanada (Td = 10.7%) and Dyvo / Arktis (Td = 10.6%) hybrids were distinguished by spike length transgression degree; Khvala / Kanada was noticeable for transgression frequency for this trait (Tf = 79.7%). As to the spikelet number per spike, the highest degree of transgressions were observed in Khvala / Viglanka (Td = 16.4%) and the highest frequency of transgressions - in Khvala / Viglanka (Tf = 51.3%) and Vodohrai Bilotserkivskyi / Arktis (Tf = 51.3%). The maximum advantage over the better parent in terms of the kernel number per spike was detected in Ladyzhynka / Arktis (Td = 13.6%); this combination was also noticeable for the maximum frequency of transgressions of this trait (Tf = 47.0%). By spike weight transgression degree, Ladyzhinka / Arktis was distinguished (Td = 26.2%); by transgression frequency for this trait – Vodohrai Bilotserkivskyi / Kanada (Tf = 60.7 %). The maximum degree of transgressions of kernel weight per spike was observed in Ladyzhynka / Arktis (Td = 29.7%) and the maximum frequency of transgressions of this trait - in Dyvo / Viglanka (Tf = 55.0%). By thousand kernel weight transgression degree, Dyvo / Donera (Td = 11.9%) and Vodohrai Bilotserkivskyi / Viglanka (Td = 11.2%) were selected and by transgression frequency for this trait - Vodohrai Bilotserkivskyi / Viglanka (Tf = 92.0%).
Conclusions. The degree of positive transgressions of spike length among F2 hybrids from diallel crossings averaged 6.9% and the frequency – 52.6%; for the spikelet number per spike the corresponding parameters were 7.8% and 44.8%; for the kernel number per spike – 5.4% and 21.4%; for spike weight – 6.3% and 23.4%; for kernel weight per spike – 6.9% and 22.5%; and for thousand kernel weight – 0.1% and 31.2%. The degree of positive transgressions of spike length among F2 hybrids from tester crossings averaged 4.6% and the frequency – 36.5%; for the spikelet number per spike the corresponding parameters were 6.9% and 30.5%; for the kernel number per spike – 5.4% and 26.0%; for spike weight – 10.1% and 30.2%; for kernel weight per spike – 11.8% and 30.3%; and for thousand kernel weight – 2.4% and 34.0%.