Gene action and genetic parameters of characters related to rice grain quality

Information about gene action, heritability, heredity, and potential gain estimated by selecting these characters is scarce. This study aims to estimate genetic parameters related to physical attributes of rice (Oryza sativa L.) grain quality. The crosses “BR/IRGA 409″ × “BRS Bojuru” and their reciprocal were performed, obtaining F1 and F2 generations and backcrosses (BC1 and BC2). After obtaining seeds, the experiment was conducted following a completely randomized design with replications determined by the total number of plants of each generation. Total chalky area (CA), white core (WC), vitreous whiteness (VW), caryopsis length (CL), caryopsis width (CW), caryopsis length × width (CL/CW), percentage of whole grains (WHO), and broken grains (BG) were evaluated. The experiment analyzed means and variances and genetic parameters of generations based on a complete model and additive‐dominant model. The physical attributes are inherited quantitatively, and the main genetic effect is the additive. However, there is a great environmental influence on the characters studied. The BR/IRGA 409 × BRS Bojuru cross makes it possible to obtain a greater genetic gain in the selection of chalky grain characters (CA, WC, and VW) as they express a narrower heritability, whereas BRS Bojuru × BR/IRGA 409 makes it possible to obtain a greater genetic gain in the selection of CL, CW, CL/CW, WHO, and BG. Parent plants affect the type of gene action. A gene action of partial dominance, overdominance, and complete dominance occurred among the physical attributes of grain quality. Core Ideas Gene action study for characters is related to rice grain quality. The experiment analyzed means and variances and genetic parameters of generations based on a complete model and additive‐dominant model. The physical attributes of rice grain quality have a quantitative genetic inheritance, and the additive intragenic action stands out as the main genetic effect.