Localization of Chromosomal Regions Determining Magnesium and Calcium Content in Rice Varieties

There has been a wide variation in the content of micro- and macroelements, both between subspecies and within rice species and varieties. Magnesium as a cofactor is involved in more than 300 enzymatic reactions and is necessary for growth and development of both plants and humans. It affects carbohydrate and protein metabolism. Both adenosine triphosphate (ATP) production, nucleotide and glucose synthesis, and lipid oxidation regulation depend on its concentration. Calcium is also essential for the formation of cell wall structure and cell division. High concentrations of calcium change the composition and condition of red blood cell membranes and cell morphological characteristics. At the same time, the variability in traits of domestic rice varieties has not yet been studied. There have been no studies on the localization of chromosomal regions responsible for the formation of traits of magnesium and calcium content in rice samples. Wide variation in calcium content (0.07-2.33%) and magnesium content in rice samples (2-14%) was established. Contrasting groups of varieties and sources by traits were identified. A search for chromosomal regions determining the quality of domestic samples was carried out using 58 molecular markers distributed across the rice genome (SSR). The data on phenotyping of native rice varieties by quality features were used to divide them into groups with maximum trait value (1) and minimum trait value (2). The relationship between phenotypic manifestation of the trait and the genotype of the sample was established by means of analysis of variance. Eight loci determining magnesium and calcium content in native rice varieties were identified. The loci determining magnesium content are located on chromosomes 5, 6, 7, and 8. Four loci associated with calcium content were identified: two on the second chromosome and one each on the eighth and fifth chromosomes. On the fifth chromosome, it is located (RM 13, 28.6 cM) in close proximity to the RM 405 marker region (28 cM), which is connected with magnesium content.