Abstract |
In the article of cytoembryological research, described the results of aneuploids progeny studying. Aneuploid forms with unbalanced chromosome number were taken 2п = 23, 2п = 28, 2п = 29, 2п = 30, 2п = 34, 2п = 35, 2п = 37, 2п = 38, 2п = 39, secreted from tetrapodal variety of Bila Tserkva origin and haploids 2п = 18 (recurrent and bidirectional diploids of aneuploids progeny). Meiosis, gametogenesis and embryogenesis processes were investigated. As a control served typical tetraploids 2п = 36, improved in quality of pollen 2п = 36 (type 1) and tetraploids 2п = 36 with pollen of bad quality.
A number of deflections in chromosomes conjugation were observed in aneuploid plants meiosis. Distortions of metaphase I, anaphase I were the result of this. Methods of sugar beet genetic turnover are suggested.
When investigating aneuploids gametogenesis with 28, 34, 39 chromosomes, irregular mitosis of pollen grains were discovered. Polyspermy phenomenon was the result of this.
The size of pollen grains varies from 8,1 micron to 38,0 micron. Small pollen grains are usually sterile.
Greater distortions occure more often in aneuploid embryogenesis than in tetraploid. But even small amount of their seed reach ordinary structural composition, physiological maturity which provide good germination.
Typical biostructural characters as polyembryos and pistillody and others were exhibited in aneuploid 2п = 23, 2п = 28, 2п = 29, 2п = 30, 2п = 34, 2п = 35, 2п = 37, 2п = 38, 2п = 39 and dihaploid plants(2п = 18), which allows to attribute them to apomicts. The availability of unreduced ovigerms indicates the sugar beet agamospermy presence.
Methods of sugar beet genetic turnover were provided as a result of profound research of aneuploidy progeny and dihaploid derived from tetraploid. |
Key words |
Genom distortions, tetraploids, aneuploids, dihaploids, gametogenesis, meiosis, pollen, embryogenesis, embryo, apomixic, trisomic, monosomic, nullisomic. |