INHERITANCE OF FLOWER PETAL COLOR IN BROWN MUSTARD
The article presents the results of studies to establish the nature of the inheritance of light yellow and cream-colored petals of mustard-gray flowers. It has been established that the cream coloring of the petals of the mustard-gray flowers in the Dijonka and Retro varieties is due to one gene in the recessive state, and the pale yellow color of the petals of the mustard flowers of the Svetlana variety is due to another gene in the recessive state. The resulting cleavages of 12: 3: 1 indicate the presence of epistasis of cream-colored alleles over pale yellow. Mustard is a valuable diversified oilseed crop. It is represented by three species of the family Brassicaceae : brown mustard (sarepta) ( Brassica juncea Czern.), white mustard ( Brassica alba L. ) and black mustard ( Brassica nigra Koch.). Which have many common morphological and biological characteristics, and the species difference is associated with different origins (Mahmudur et al, 2018). The most common is gray mustard. Domestic varieties of this type listed in the Register are slightly different among themselves, although today there is an acute issue of protection of intellectual property rights. Scientists of the Institute of Oilseeds of the National Academy of Agrarian Sciences, using chemical mutagenesis, managed to create mustard varieties with distinctive morphological traits, the presence of which facilitates their easy identification. Retro, Dijonka and Svetlana mustard varieties are characterized by a distinct creamy and light yellow color of the petals of flowers, which is not typical of mustard grayish (Zhuravel, 2011). Morphological markers for mustard are primarily the color of flower petals and seeds (Jianjun Zhao, 2007). Mustard has been studying the genetics of coloring petals of flowers for about 70 years. First, it was found the presence of white color of petals of flowers in different types of mustard. In gray mustard ( Brassica juncea Czern.), It is controlled by the recessive state of two independent genes (Singh et al, 1968), and in another species of Brassica carinata, both monogenic (Getinet et al, 1993) and digital control of white coloration were indicated. flower petals (Heyn, 1973). Later, a study was conducted using molecular markers of the Bjpc1 and Bjpc2 genes, which determine the white color of the flower petals, and the molecular markers and the location of the genes on the A02 Brassica rapa chromosome were determined. (Xiangxiang et al, 2018, Zhang X, et al, 2018). The purpose of our study was to establish the nature of the inheritance of the sign of the color of flower petals in varieties of mustard gray. The material used was the varieties of mustard gray-gray selection of the Institute of Oilseeds NAAN - Retro, Dijonka, Svetlana, Demetra, Prima, Mriya and Tavrichanka with different color of flower petals. The color of the flower petals in Dijonka and Retro varieties is designated by us as cream, in Svitlana varieties - pale yellow, in the mustard varieties Prima, Demetra, Tavrichanka and Mriya - the usual golden-yellow color of flowers. To determine the nature of the inheritance of the character of the color of the petals of flowers, crosses were carried out using manual castration and subsequent pollination of the parent components with pollen using individual isolators. Seeds of mustard hybrids, obtained from each insulator, were sown separately on one or two row plots and grown according to the usual technology. Evaluation of the color of mustard flowers was carried out visually, comparing with the color of the flowers of the parent components. Statistical significance was established using the Pearson criterion (Lakin, 1990). The distinctive color of the flower petals - cream and light yellow in mustard - gray was obtained by applying chemical mutagenesis and inserting descendants. To establish the nature of the inheritance of this trait, a series of crossing combinations were carried out. As the maternal component used varieties of mustard - Mriya, Demetra, Tavrichanka with golden yellow color of flower petals and Svetlana variety with a light yellow color. The first generation hybrids in all cross-breeding combinations had a golden-yellow color of flower petals, although varieties with all studied flower colors were used as father. In the second generation of mustard we observed splitting of plants with flower color into two and three types. In a combination of Mriya×Dijonka crossing in the second generation, the colors of the flowers were split into golden yellow and cream in a ratio of 3:1. There were more plants with golden yellow flower petals than cream ones. A statistical check by the Pearson criterion confirmed the accuracy of the 3:1 ratio hypothesis (plants with a golden-yellow color to plants with cream). This testifies to the monogenic recessive control of the cream coloring of the flower petals of the Dijonka variety in relation to the Mriya variety with golden yellow color. In the F<sub>2</sub> generation from the crossing of the parent components of the varieties Demetra and Dijonka, three types of coloration were revealed: golden yellow, cream and pale yellow, which are not characteristic of parental phenotypes. The resulting splitting corresponds to a ratio of 12:3:1. This indicates the presence of two genes responsible for the color of the flower petals in these plants. In the F2 generation, from the combination of Demetra × Retro, 51 plants were obtained with golden yellow flower petals, 6 with cream and 1 with pale yellow. One plant in a small class cannot reliably confirm the ratio of 12:3:1, but close enough to it and identical with the previous combination of crossing Demetra×Dijonka. To establish the inheritance of a pale yellow color of flowers, three variants of crossing were carried out. In combinations of crossing Svetlana×Mriya, Svetlana×Prima and Tavrichanka×Svetlana in the first generation observed plants with golden-yellow flowers. In the F<sub>2</sub> generation, plants with golden yellow and pale yellow color of flower petals were found in a ratio of 3:1. The test carried out according to the Pearson criterion confirmed the hypothesis reliability: a ratio of 3 golden yellow to 1 pale yellow. This indicates a monogenic recessive control of the pale yellow color of the flower petals in Svetlana. Summarizing the established ratios of plants for the color of flower petals in the F<sub>2</sub> generation, it was found that the pale yellow color of flowers is due to one gene in the recessive state, the cream color of flowers is caused in one combination by one gene in the recessive state, in two other combinations with Demetra variety the appearance of pale yellow colored petals of flowers. This means that the Demetra variety also has a gene that is involved in the manifestation of a pale yellow color. The resulting ratio shows that the effect of the recessive alleles of the gene, which cause a pale yellow color, appears on the background of a cream color. To further clarify the nature of the inheritance of the color pattern of the petals of the mustard, self-pollination of second-generation hybrids was carried out and third-generation hybrids were obtained. In a combination of Mriya×Dijonka crossing from F<sub>2</sub> plants with golden-yellow color of flower petals, 3:1 splitting was found in two offspring, which confirms monogenic recessive control of the sign of cream color of flower petals in this combination. In one offspring, no splitting was observed and the color of the flower petals was only golden yellow. In the Demetra×Dijonka crossing combination, the F<sub>2</sub> plant with cream colored flowers had descendants with the same color. One F<sub>2</sub> offspring with golden yellow flowers did not split, the second had two classes with a 3:1 splitting, and only the third corresponded to the 12:3:1 ratio, as in the F<sub>2 </sub>splitting with the appearance of a class of pale yellow offspring. In the Demetra×Retro crossing combination, three splittings in F<sub>3</sub> reliably corresponded to a ratio of 3 golden yellow to 1 cream. This confirms the conclusion of a monogenic recessive control of the trait of cream coloring of flower petals. In one crossing, a class of plants with pale yellow flowers was obtained in a ratio of 12:3:1, as in the second generation. In combinations of crossing Tavrichanka×Svetlana, Svetlana×Prima, Svetlana×Mriya from F<sub>2</sub> plants with pale yellow flower petals in F<sub>3</sub>, all plants had a pale yellow color of flower petals. In the progeny of F<sub>3</sub> plants (F<sub>2</sub> with golden yellow flowers), two classes of descendants were obtained with golden yellow and pale yellow flower petals, which corresponded to a 3:1 ratio. Summarizing the resulting splittings in the second and third generation, the monogenic recessive control of the trait of cream coloring of flower petals was unequivocally confirmed. The pale yellow color of mustard flowers is due to another gene in a recessive state. The resulting cleavages of 12:3:1 indicate the presence of epistasis of cream-colored alleles over pale yellow. The established ratios do not contradict the studies of other scientists who obtained results on the presence of digital control of the white color of petals of mustard flowers (Singh et al, 1964; Rawat & Anand, 1986; Brar et al, 1991). In their studies, several splits were also obtained with a ratio of 12:3:1. The light yellow and creamy colors of the flower petals we obtained cannot be called white, as described in other scientific studies (Singh et al, 1964; Rawat & Anand, 1986; Brar et al, 1991). Each researcher can describe them with different phrases, so perhaps one of these types of coloring is just that. To identify now we do not have the opportunity. Further study of these varieties and a more detailed study of the detected types of color will make it possible to identify additional genes. It is proved that the cream coloring of the mustard flower petals in Dijonka and Retro varieties is due to one gene in a recessive state, and the pale yellow color of mustard flowers in Svetlana is caused by another gene in a recessive state. The resulting cleavages of 12:3:1 indicate the presence of epistasis of cream-colored alleles over pale yellow.