Effective protocol for rice phenotyping based on grain quality: Ranking of rice samples from a segregating BC

The physical properties of rice backcross samples were studied in connection with the development of an effective breeding methodology for creating rice genotypes based on an accelerated breeding process. The purpose of the research was to study the traits of size, vitreousity, and fracturing of samples of the segregating population of BC2 reseedings from the 2022 and 2023 yield. As part of the program for developing varieties based on the use of modern post-genomic and cellular technologies, BC2 samples were used; as parent forms – samples of the USI “Collection of Federal Scientific Rice Centre” of various groups according to the shape of the grain. The crop was grown in artificial climate chambers under controlled conditions of light and air temperature and on the growing site of Federal Scientific Rice Centre. In the study, white grain samples from the segregating BC2 population were isolated for large-scale genotyping. The cultivation of parental forms for hybridization and the crossing process were carried out in artificial climate chambers. Hybridizations were performed using pneumocastration, which included cutting off the flower scales by 1/3 and then removing the anthers using a vacuum compressor. White grain BC2 samples were isolated for research. Seeds were sown on the growing area in containers with 6 kg of soil and Pryanishnikov’s mixture as the main fertilizer. After ripening, the seeds were manually harvested. Plant phenotyping of experimental populations was carried out basing on grain quality traits using certified equipment in accordance with the instructions for the devices and GOST standards. For 15 combinations, samples with the best characteristics of grain quality were selected. In connection with the indicators of physical grain quality traits, BC2 samples were classified into three groups with indicators for each trait: high, medium, low.