Technology of sugar beet dihaploid lines development

E.N. Vasil¿chenko, O.A. Zemlyanukhina, N.A. Karpechenko, V.N. Kalaev
The first stage includes the selection of genotypes by the following genotypic features: apocarpy/syncarpy, shrub mien, qualitative pollen characters, and ploidy of plants. Unfertilised ovules with eight-nucleate embryo sacs are used as explants. The Gamborg medium B5 (2 mg L‑1 BAP) allows to produce (7.4%) haploid regenerants that are viable up to 4-6 months. The transfer into a solid medium (1.9 mg L‑1 BAP, 3 g L‑1 gelrite) results in shoot induction. The simultaneous application of BAP, kinetin, and gibberellin (0.2 mg L‑1) allows the formation of normal plants (95%) and axillary shoots. Cytophotometric ploidy analysis is used to select and form lines with an exclusively haploid chromosome set (n=9). To create homozygotic lines, the haploids are exposed to colchicine (0.005 mg L‑1, 2 days). The yield of diploid plants is 91.3%, there are also some triploid and tetraploid plants. Cultivation in kinetin slows down the development of haploid tissue, stimulates the fission of diploid cells, and stabilises growth processes. Rhizogenesis stimulation is observed when 1 mg L‑1 of indolebutyric acid, alpha-naphthalene acetic acid, and 3 g L‑1 of activated carbon are added to the medium. Adaptation to non-sterile conditions lasts 2-3 days and is conducted at 100% air humidity in the mixture of sand and organic matter (1:1). Stecklings weighing 16-100 g are formed within 2-3 months. Jarovization lasts 45 days and (in order to obtain seed plants) is conducted at low light intensity and at +4°С. When the stems start to form, the temperature is increased to 14-20°C and the light intensity is increased to 1,000 lx. After a month, normal shrub miens and flower buds are formed and the plants start blossoming. After 8-10 weeks, seeds with high apocarpy are formed. The innovative technology for production of restitutional lines makes it possible to obtain seeds of homozygotic lines at a higher rate - these are components of high yield hybrids of sugar beet.
Vasil¿chenko, E.N., Zemlyanukhina, O.A., Karpechenko, N.A. and Kalaev, V.N. (2021). Technology of sugar beet dihaploid lines development. Acta Hortic. 1324, 131-136
DOI: 10.17660/ActaHortic.2021.1324.20
sugar beet, in vitro, haploids, dihaploids, technology

Acta Horticulturae