Avaliação do progresso genético obtido em 22 anos no melhoramento do arroz irrigado em Minas Gerais Evaluation of the genetical progress obtained in 22 years on the improvement of irrigated rice in Minas Gerais, Brazil

Autor: Patrícia Guimarães Santos, Plínio César Soares, Antônio Alves Soares, Orlando Peixoto de Morais, Vanda Maria de Oliveira Cornélio
Jazyk: English<br />Spanish; Castilian<br />Portuguese
Rok vydání: 1999
Předmět:
Zdroj: Pesquisa Agropecuária Brasileira, Vol 34, Iss 10, Pp 1889-1896 (1999)
Druh dokumentu: article
ISSN: 0100-204X
1678-3921
DOI: 10.1590/S0100-204X1999001000016
Popis: O objetivo deste trabalho foi avaliar o desempenho do programa de melhoramento genético do arroz irrigado, no Estado de Minas Gerais. Foram utilizados os dados de produtividade de grãos dos ensaios comparativos avançados de cultivares e linhagens de arroz irrigado, conduzidos em várias microrregiões do Estado de Minas Gerais, durante o período de 1974/75 a 1995/96. O ganho genético médio obtido em todo o período foi de 33 kg/ha/ano (0,98%), sendo altamente significativo (PThe goal of this work was to evaluate the performance of the genetical improvement program of irrigated rice in the State of Minas Gerais, Brazil. The grain yield data of the advanced comparative trials of both cultivars and lines of irrigated rice, conducted in several regions of the State of Minas Gerais over the period of 1974/75 to 1995/1996 were utilized. The average genetical gain obtained was of 33 kg/ha/year (0.98%), being highly significant (P< 0.01). The 22 year period was subdivided into two phases: at the first phase (1974/75 to 1979/80), a gain of 203 kg/ha/year (6.06%) was noticed, which was highly significant, and the second phase (1980/81 to 1995/96) presented a gain of 15 kg/ha/year (0.25%) being non significant. The high gain of the first phase is ascribed to the replacement of traditional high size and poor yielding potential for breeding materials such as Inca, BG 90-2 and MG 2. In the second phase of the program, increased attention was given to obtain materials more resistant to diseases and with better grain quality and non-significant gains for yield were obtained.
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