Selection of progenies in the initial cycle of recurrent selection for early flowering and grain yield in upland rice

ABSTRACT In upland rice breeding programs, it is crucial to develop both high-yielding and early flowering lines. A successful strategy for accumulating favorable alleles in a population and increasing selection gains is the recurrent selection. This method involves repeatedly selecting and intercrossing progenies that exhibit favorable traits, with the goal of accumulating these traits in the population and subsequently extracting superior lines. Thus, the aim of the present study was to evaluate F2:4 and F2:5 progenies from the recurrent selection population UFLA-P1 at cycle 0 for early flowering and grain yield. The total of 152 F2:4 progenies was evaluated in 12 × 13 triple alpha-lattice design, totaling 468 plots. From this evaluation, 26 genotypes were selected to be included in the elite lines trial of the upland rice breeding program (MelhorArroz). Among these, 100 progenies were assessed: 26 F2:5 progenies from the recurrent selection program, 72 F4:6 progenies from MelhorArroz, and two commercial lines as controls. The annual gain achieved through recurrent selection for days to flowering was -3.48%. Additionally, 11 F2:5 progenies from the UFLA-P1 population demonstrated superior performance for early flowering, grain yield, and other favorable phenotypic traits. These progenies were selected for advancement, with the aim of releasing superior lines. This study demonstrates the potential to develop superior lines for early flowering and grain yield in upland rice, starting from cycle 0 in recurrent selection.