The genetic gains for yield obtained by the breeding program of irrigated rice in the Northeast Region of Brazil from 1984 to 1993 were estimated to evaluate the program efficiency. This estimation was done based on data from 59 regional field trials conducted by the Northeastern farm research institutions in cooperation with Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão (CNPAF), Goiânia, GO, Brazil. The statistical method used was based on adjusted means by generalized linear model. The estimated mean genetic gain was 54.9 ± 14.4 kg/ha-1/yr-1 (0,8%). However, in the last three years, there was a tendency of interrupting the gains. The small gain obtained for yield in the referred region may be attributed to the strategy adopted by the line breeding program of Embrapa, which has priority for grain quality and disease resistance, the environmental differences between Goiânia and the Northeast Region and the small number of trials conducted. The genealogy of the lines was traced back and it was identified that the main ancestors are mostly the same as the released varieties. The genetic base of the lines is narrow, which may be contributing to the small genetic gains obtained for yield.
genetic gain; genetic base; breeding program
