Features of embryonic development in sugar beet under apospory and cytoplasmic male sterility
Year: 2026
Type: article
Abstract: The aim of the study was to evaluate the theoretical foundations of the phenomenon of high seed self-reproduction in substituted lines and to develop a methodology for studying embryonic development in sugar beet breeding materials with cytoplasmic male sterility (CMS) of different genetic origins. Experimental investigations included field methods, pollen-free seed production in CMS breeding materials, laboratory methods, cytological analysis of embryo development during apozygoty over 34 days after flowering fixation, and a cytophotometric method for assessing genome-level ploidy variability in materials with different terms of apozygotic seed reproduction. The methodology for studying embryonic development during apozygoty in materials of different CMS source origins was improved, incorporating flowering marking, shoot isolation, and embryo fixation from 5 to 34 days until complete embryo development. It was established that apozygoty in sugar beet is characterised by delayed genetically determined development of 4, 8, or 10 days within the 28-day developmental cycle, depending on the origin of the material, as well as by polyembryony and a high percentage of degenerated embryos. Adventitious embryogenesis, apospory, and simultaneous embryo development from integuments and nucellus in both micropylar and chalazal regions were characteristic of male-sterile lines of different genetic origins. It was found that substituted lines based on new CMS sources derived from wild species of the genus Beta L. exhibit the phenomenon of high seed self-reproduction under pollen-free conditions. The methodology for studying embryo development synchrony was developed to investigate the nature of apozygoty (generative and somatic embryogenesis) in substituted lines with introduced sterile cytoplasms, compared with monoecious male-sterile lines carrying the F. Owen S-vulgaris cytoplasm. The type of apozygoty manifested through gametophytic and sporophytic embryogenesis and determined the genetic heterogeneity (variability in quality) of apozygotic seeds. Apomixis using substituted lines and new sterile cytoplasms derived from wild species of the genus Beta L., combined with a high percentage of apomictic seed reproduction, may provide significant advantages for the production of new crop hybrids, particularly through the fixation of heterosis and preservation of the maternal plant genotype
Source: PLANT AND SOIL SCIENCE
Authors: Mykola Roik, Nataliia Kovalchuk, Olesia Zinchenko, Yaroslav Manziuk, Roman Spriazhka
Institution: Institute of Bioenergy Crops and Sugar Beet
Language: English
Topic: Plant Reproductive Biology
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W7163662771