Spring rape (Brassica napus L.) varieties androgenesis and regenerators evaluation for pollen fertility

The purpose of research is to study the ability of spring rapeseed genotypes of domestic and foreign selection to induce embryoids in anther culture in vitro, as well as the regeneration potential of formed embryoids and the fertility of androclinic plants obtained from them. Objectives: to introduce isolated anthers into in vitro culture, to determine the frequency of induction of embryoidogenesis of the studied genotypes and their regenerative capacity. Anthers were cultivated on B5 nutrient medium supplemented with 2,4-D at a concentration of 0.1 mg/l and NAA at a concentration of 0.1 mg/l. The content of iron chelate in the medium was increased to 12.5 mg/L. Embryoid induction was obtained in all studied genotypes. According to the ability to embryoidogenesis, the studied samples differed significantly. The maximum number of embryoids (9.26 %) was obtained from the Topas variety. Seven varieties - Avangard, Bulat, Visit, Lira, Lipetsky, Ratnik, Rubezh induced embryoids with a frequency of less than 1.0 %. With the development and accumulation of chlorophyll, the embryoids were transplanted onto a nutrient medium that did not contain growth regulators, where they were incubated until the development of shoots and roots. Seedlings with a well-developed root system and 3 true leaves were transplanted into the soil. During the flowering period of plants, the inflorescences were covered with insulators for the purpose of self-pollination and to exclude the ingress of foreign pollen. Many androclinic plants obtained from primary embryoids had reduced (underdeveloped) anthers. The bulk of these plants were haploids. Some plants had wrinkled or thickened parts of the anther. Cytological analysis showed that anthers with various deviations produce little pollen, most of which is sterile. Pollen diversity is one of the main factors of low seed set under the isolator. Androclinic plants with the presence of sterile pollen are promising for use in hybridization after their genetic analysis.