Resumo
In the present paper the authors present the results of a genetic study concerning the erecta type of growth of the lateral branches of Coffea arabica L. The erecta mutant, which probably originated in Java, differs from normal coffee plants by having upright growing lateral branches instead of plagiotropic ones. However, in spite of the fact that both, the main shoot and the lateral branches grow in the same direction, the dimorphic nature of the branches still persists. The genetic studies carried out since 1933, which included the study of progenies of F1, F2 generations and backcrosses, have revealed that the erecta character is conditioned by one pair of dominant genes Er Er. It is not yet known whether all erecta plants, of different origins, have the same dominant gene, but investigations already in progress are expected to yield information on this matter. Of all genes so far studied in C. arabica, Er is the most completely dominant, the heterozygote being indistinguishable from the homozygote. The erecta gene has been found to show complete penetrance and a constant expressivity.
Genética de Coffea. XIII - Hereditariedade do caraterístico erecta em Coffea arabica L.(1 (1 ) Trabalho apresentado à Segunda Reunião da Sociedade Brasileira para o Progresso da Ciência, realizada, de 5 a 12 de novembro de 1950, em Curitiba, Paraná. )
A. CarvalhoI; C. A. KrugII
IEngenheiro agrônomo, Secção de Genética
IIEngenheiro agrônomo, diretor do Instituto Agronômico de Campinas
SUMMARY
In the present paper the authors present the results of a genetic study concerning the erecta type of growth of the lateral branches of Coffea arabica L. The erecta mutant, which probably originated in Java, differs from normal coffee plants by having upright growing lateral branches instead of plagiotropic ones. However, in spite of the fact that both, the main shoot and the lateral branches grow in the same direction, the dimorphic nature of the branches still persists.
The genetic studies carried out since 1933, which included the study of progenies of F1, F2 generations and backcrosses, have revealed that the erecta character is conditioned by one pair of dominant genes Er Er. It is not yet known whether all erecta plants, of different origins, have the same dominant gene, but investigations already in progress are expected to yield information on this matter.
Of all genes so far studied in C. arabica, Er is the most completely dominant, the heterozygote being indistinguishable from the homozygote. The erecta gene has been found to show complete penetrance and a constant expressivity.
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LITERATURA CITADA
- 1. Carvalho, A., C. A. Krug e J. E. T. Mendes. O dimorfismo dos ramos em Coffea arabica L. Bragantia 10 : 151-159, est. 1-4. 1950.
- 2. Krug, C. A. Genética de Coffea - Boletim Técnico do Instituto Agronômico de Campinas 26 : 1-39. 1936.
- 3. Krug, C. A. e A. Carvalho. The Genetics of Coffea. Proceedings of the eigth international congress of genetics. Heréditas, Supplementary volume: 611-612. 1949.
- 4. Krug, C. A., J. E. T. Mendes e A. Carvalho. Taxonomia de Coffea arabica L. Boletim Técnico do Instituto Agronômico de Campinas 62 : 1-57, est. 1-58. 1939,
- 5. Mc Clelland, T. B. Coffee varieties in Porto Rico. Bul. Porto Rico Agric. Exp. Sta. (Mayaguez) 30 : 1-27, est. 1-9. 1924.
Datas de Publicação
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Publicação nesta coleção
09 Jun 2010 -
Data do Fascículo
1950
