Genetic progress in the UNB-2U population of popcorn under recurrent selection in Rio de Janeiro, Brazil

As part of the Universidade Estadual do Norte Fluminense recurrent selection program of popcorn, we evaluated full-sib families of the sixth cycle of recurrent selection and estimated genetic progress for grain yield and expansion capacity. We assessed 200 full-sib families for 10 agronomic traits, in a randomized block design, with two replications within sets in two environments: Campos dos Goytacazes and Itaocara, in the State of Rio de Janeiro, Brazil. There were significant differences for families/"sets" for all traits, indicating genetic variability that could be exploited in future cycles. In the selection of superior progenies, the Mulamba and Mock index gave the best gains for popping expansion (PE) and grain yield (GY), with values of 10.97 and 15.30%, respectively, using random economic weights. By comparing the evolution of the means obtained for PE and GY in the cycles C(0), C(1), C(2), C(3), C(4), C(5), and predicted for C(6), a steady increase was observed for both PE and GY, with the addition of 1.71 mL/g (R(2) = 0.93) and 192.87 kg/ha (R(2) = 0.88), respectively, in each cycle. Given the good performance of this popcorn population in successive cycles of intrapopulation recurrent selection, we expect that a productive variety with high expansion capacity will soon be available for producers in the north and northwest regions of Rio de Janeiro State, Brazil.