Genetic potential and cytoembryological characteristics of Beta vulgaris L. lines of apozigotic reproduction

Abstract

Purpose. To investigate the possibility of transferring elements of apozigotic reproduction (adventitious embryo) to combinational-valuable CMS lines; to carry out screening of breeding materials of the Verkhniatska Research Breeding Station for apomictic reproduction. Methods. Cytoembryological methods of embryogenesis, microsporogenesis.Results. It was found that the bulk of pollen grains of all the breeding materials under study belonged to the type b. In addition, they were characterized by a high variability of pollen grains (12.0 to 26.0 microns) that indicated the instability of the breeding materials. The line Sf (I2S1I11) had genotypes with the pollen type c. The type of pollen indicates the presence of unreduced pollen grains and it is a marker of the presence of unreduced parthenogenesis, which relates to regular apomixis. Most of the anomalies in embryological development were recorded in accessions F1 CMS 2-1 No. 120, 123 (8–10%), and F2 CMS 25 No. 105, 102 (6.0–7.3%). The following anomalies of the embryo were detected: the location of the embryo in the pectoral part, the medial position of the embryo, coenocytes. The SF line of I2S1I11 No. 3314 was characterized by the largest number of apomictic embryo clusters (55%). The presence of coenocytes was detected.Conclusions. The possibility of transferring the adventitious embryo from the donor [Sf line (I2S1I11)] to the combinational-valuable MS lines was studied. It has been established that the line F2 MS 25 shows a greater tendency to form apomictic germs (7.3–14.9%), compared with F1CMS 2-1 (5.0–12.5%). The analyzed CMS lines of the Verkhniatska RBS were characterized by certain instability under the cytoembryological test.