This paper had the objective of quantifying the genetic progress of lowland rice in the state of Amapá, Brazil, in the 1991-1996 period. The efficiency of the rice lineages evaluation and selection program was studied, using grain yield data, obtained in the Advanced Yield Trials, of the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão network. To estimate the genetic gain the methodologies of Vencovsky et al. (1986) and Fernandes (1988) were used. The genetic gain obtained was of 2.45%/ year (78.9 kg ha-1), being 63.21% of the whole progresses due to the genetic breeding, for the first method. In the second method, the genetic gain was of 3.02%/year (96.93 kg ha-1), being 67.85% of the whole progresses due to the genetic breeding. The genetic gains obtained in both methodologies evidence that the efforts undertaken in the search of adapted and productive cultivars have been producing expressive results.
Oryza sativa; genetic gain; lineage evaluation
