Full text in pdf format

 

Proposal for applying combined selection to diallel analysis

 

 

Cleso Antônio Patto PachecoI; Maria Amélia Gava FerrãoII; Cosme Damião CruzIII; Roland VencovskyIV;

IEMBRAPA-CNPMS, Caixa Postal 151, 35701-970 Sete Lagoas, MG, Brasil. Send correspondence to C.A.P.P.
IIEMCAPA-EEL, Caixa Postal 62, 29900-970 Linhares, ES, Brasil.
IIIDepartamento de Biologia Geral, UFV, 36570-000 Viçosa, MG, Brasil.
IVESALQ-USP, Caixa Postal 83,13400-970 Piracicaba, SP, Brasil.

 

 

ABSTRACT

The philosophy of intrapopulation combined selection is the search for and identification of individuals with superior genotypic behavior, based on their performance compared to the family mean and, at the same time, of their family mean in relation to the population mean, through the weighting of the phenotypic values represented, respectively, by the within and among families heritability coefficient. The objective of this study was to adapt and apply this philosophy to diallel analysis. The crosses were considered as having fixed effects and selected on the basis of their specific combining ability (SCA), and on the mean performance of the two involved parents, in relation to the general combining ability (GCA). This work was based on Griffing's (Heredity 10: 35-50, 1956) method 2, model 1 which involves p(p + 1)/2 treatments. The proposed index resulted from the weighting of the effects of GCA (gi's) and SCA (sij's) by the respective determination coefficients of additive and dominant genetic determinations, resulting from the partitioning of the total genotypic determination coefficient. An example is given for illustration.

Keywords: combined selection; diallel analysis.

 

 

REFERENCES

Cruz, C.D. (1995). Seleção combinada. In: Notas de Aulas do Curso de Genética Quantitativa Aplicada ao Melhoramento de Plantas - FIT 770. UFV, Viçosa, MG (mimeografado).

Cruz, C.D. and Regazzi, A.J. (1994). Modelos Biométricos Aplicados ao Melhoramento Genético. UFV, Impr. Univ., Viçosa, MG, pp. 390.

Cruz, C.D. and Vencovsky, R. (1989). Comparações de alguns métodos de análise dialélica. Rev. Bras. Genet. 12: 425-438.

Falconer, D.S. (1981). Introdução à Genética Quantitativa. UFV, Impr. Univ., Viçosa, MG, pp. 279.

Delbóni, J.S., Silva, J.C., Cruz; C.D. et al. (1989). Análise de cruzamentos dialélicos entre variedades de milho braquítico usando o método de Gardner e Eberhart. R. Ceres, 36: 365-372.

Gardner, C.O. and Eberhart, S.A. (1966). Analysis and interpretation of the variety cross diallel and related populations. Biometrics 22: 439-452.

Gomide, B.G. (1980). Cruzamentos dialélicos entre variedades de milho (Zea mays L.). Master's thesis, UFV, Viçosa, MG, pp. 71.

Griffing, B.A. (1956). A generalized treatment of the use of diallel crosses in quantitative inheritance. Heredity 10: 31-50.

Miranda, J.E.C. (1987). Análise genética de um cruzamento dialélico em pimentão (Capsicum annuum L.). Doctoral thesis, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP, pp. 159.

Paini, J.N. (1994). Capacidade combinatória e heterose em oito variedades de milho (Zea mays L.), avaliadas sob condições climáticas da região sul do Brasil. Master's thesis, UFV, Viçosa, MG, pp. 125.