Rice (Oryza sativa L.) plant architecture is crucial in rice productivity enhancement, particularly in forecasting agronomic-related traits. The presented research characterized the shoot architecture, photosynthesis, and yield-related traits in the F9 generation of rice recombinant inbred lines (RILs) derived from a cross between cultivar IR64 and local cultivar Hawara Bunar through correlation and path analyses among the various features. Rice RILs and parental cultivars’ sowing transpired in the greenhouse and the field. The greenhouse experiment commenced growing the rice seeds of 90 RILs and their parental lines in PVC tubes (20 cm in diameter and 50 cm in height) with sand soil as a medium. The study employed the upland rice cultivation system for the field experiment to cultivate the rice genotypes. The study used a randomized complete block design (RCBD) with three replications. Shoot plant architecture, physiological, and yield traits observation continued at various stages of plant growth. A significant positive correlation to the seed yield per plant appeared in the maturative stage by the total seed weight, transpiration efficiency, intercellular CO₂ concentration, and intercellular CO₂ pressure. A substantial positive indirect effect on grain yield also surfaced from the net transpiration rate and its efficiency, intercellular CO₂ concentration, and CO₂ pressure. Therefore, the shoot architecture significantly affects the photosynthetic rate and grain yield.

Keywords: Path analysis, physiological traits, rice, recombinant inbred lines (RILs), yield

Key findings: Correlation and path analyses revealed a relationship among shoot architecture, photosynthesis rate, and yield-related traits in the 9^th generation of rice recombinant inbred lines (RILs) derived from a cross between cv. IR64 × Hawara Bunar.