Lipids are the basic biological molecules in plants, serving as glycerolipids for cell membranes and triacylglycerols as an energy source. Fatty acids are the major components of plant lipids. Both lipids and fatty acids significantly influence rice quality. Recent studies, through genetic analysis, have made significant progress in uncovering the functional mechanisms and regulatory pathways of lipid metabolism including the biological synthesis and degradation of fatty acids, glycerolipids, and triacylglycerols in rice. Meanwhile, quantitative trait loci (QTLs) identified by analyzing the natural variations of the composition and contents of lipids and fatty acids have been integrated and represented on 12 chromosomes. Lipids play multifaceted roles in the growth and development and stress response of rice. Through metabolic engineering and gene-editing technologies, significant advancements have been made in improving the lipid content in rice grains. These studies highlight the understanding the of molecular basis of lipid metabolism and lay a substantial basis for the genetic improvement of rice quality.

This article examines the survivability of rice plants from the seedling transplanting stage to harvest depending on fertilizer application rates and planting density. The results of the study showed that, when assessing the effect of nitrogen fertilizers on rice seedlings, the treatment with a fertilizer rate of N120P60K90 resulted in relatively higher plant survivability per 1 m² area before harvest. Among the planting density treatments of 1333, 750, and 480 plants/ha, the highest pre-harvest survivability was observed at a density of 750 plants/ha. It was found that an increase in the number of seedlings per unit area led to a decrease in plant survivability up to harvest, whereas an increase in nitrogen fertilizer rates had the opposite effect, improving plant survivability. A strong negative correlation was identified between planting density and seedling survivability (r = –0.93), while a positive correlation was observed between nitrogen fertilizer rate and seedling survivability (r = 0.56).

Grain quality traits of F6 rice lines were analyzed in a control seedling nursery. Grain yield ranged from 67.2 to 70.1 %, whole grain yield from 84.6 to 87.2 %. Grain length varied from 8.2 to 9.0 mm, width from 3.0 to 3.4 mm, and length-to-width ratio (L/W) from 2.8 to 3.1. Lines S-106, S-123, and S-118 demonstrated high technological quality and are considered promising starting material for breeding programs.

The article investigates the inheritance patterns of the vegetation period trait in rice (Oryza sativa L.) in F1 and F2 hybrid generations. The study analyzed hybrids obtained from crosses involving local and foreign varieties, assessing the duration of the vegetation period, degree of dominance (hp), coefficient of variation (CV%), and broad-sense heritability (H²). In the F1 generation, negative, intermediate, and high dominance for vegetation period duration were identified. In the F2 generation, the trait varied within the range of 106–128 days, with wide phenotypic segregation observed. The H² values ranging from 0.77 to 0.98 indicate strong genetic control of the trait. The results confirm that vegetation period duration is a polygenic and complexly inherited trait, providing opportunities for effective selection of early-and medium-maturing forms in breeding programs.