Evaluation of quality of experimental white-grain rice populations in accelerated breeding by grain size and vitreosity

Background. In marker-assisted rice breeding, the accelerated development of varieties with superior grain quality traits through advanced biotechnological approaches requires the generation of segregating rice populations followed by phenotyping of genotypes for traits of interest. These segregating populations are used to identify genetic loci (QTLs) associated with complex traits, including rice grain quality, based on phenotypic data.

Purpose. The goal of the work was to evaluate experimental BC3 populations of rice based on physical characteristics of grain: size, vitreousity, fracturing, in order to carry out work on targeted selection based on phenotyping and genotyping data of promising plants - prototypes of varieties with specified traits in marker-assisted rice breeding.

Materials and methods. The study involved hybrids of 15 combinations of parental forms. The seeds were sown in vessels on the vegetation site of FSBSI Federal Scientific Rice Centre, Pryanishnikov’s mixture was used as the main fertilizer; as they ripened, the seeds were harvested manually. High-tech methods of phenotyping the breeding material were used to conduct the research. The grain size was estimated by the mass of 1000 absolutely dry grains using a moisture analyzer, an air-heat unit, and an automatic seed counter; the vitreousity and grain fracturing were estimated in transmitted light using a diaphanoscope.

Results. Genotypes were differentiated and distributed into groups for each trait. As a result of the quality study of the obtained BC3 samples, lines combining high technological grain quality traits were identified using phenotyping data. The mass of 1000 absolutely dry grains was in the range of 23.2-30.2 g in the group of medium-weight samples, the indices of vitreousity and fracturing were 62-93% and 1-9%, respectively.

Conclusion. As a result of the comparative analysis of hybrids and parental forms, combinations were noted for which the heterosis effect was typical for grain quality traits.