Use este identificador para citar ou linkar para este item: https://locus.ufv.br//handle/123456789/27115
Tipo: Artigo
Título: Incorporating different proportions of exotic maize germplasm into two adapted populations
Autor(es): Peternelli, Luiz Alexandre
Santos, Manoel Xavier dos
Pollak, Linda Maria
Pacheco, Cleso Antônio Patto
Guimarães, Paulo Evaristo Oliveira
Parentoni, Sidney Netto
Nass, Luciano Lourenço
Abstract: Maize breeders frequently wish to use exotic germplasm in their breeding programs without losing specific characteristics of their adapted material. The objective of this study was to determine the optimal proportions of exotic germplasm to incorporate into adapted populations (F2 = 50% exotic, BC1 = 25% exotic, BC2 = 12.5% exotic and BC3 = 6.25% exotic) to form the initial foundation population and to determine the heterosis between adapted x exotics. We used six exotic populations of different origins and two adapted populations representing a Brazilian heterotic pattern. In 1993-94 and 1994-95, the parents, F1, F2, BC1, BC2, BC3 and four checks were evaluated in six environments in central Brazil using an 8 x 9 simple rectangular lattice design. Higher mean values for yield were obtained as the proportion of exotic germplasm decreased. Some backcrosses produced more than the adapted populations BR 105 (7.59 ton/ha) and BR 106 (8.43 ton/ha). The best results were obtained when incorporating 6.25 or 12.5% of exotic genes. This trend was true for root lodging, stalk lodging and ear diseases but not for plant and ear height. The midparent heterosis for yield varied from -16.1 to 40.3%. Midparent heterosis with positive and negative values were also found for the other traits. The results indicate the potential of exotic germplasm for developing good hybrids. After choosing the best exotic source, some recurrent selection might be appropriate in order to adapt and improve the exotic populations.
Palavras-chave: Incorporating
Exotic maize
Germplasm
Populations
Editor: Genetics and Molecular Biology
Tipo de Acesso: Open Access
URI: http://dx.doi.org/10.1590/S1415-47572000000200033
https://locus.ufv.br//handle/123456789/27115
Data do documento: Jun-2000
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