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Heritability and genetic gain for resistance to leaf blight in carrot (Daucus carota L) populations evaluated at different times after sowing

Jairo Vidal Vieira^I; Vicente Wagner Dias Casali^II; João Camilo Milagres^III; Antonio Américo Cardoso^II; Adair José Regazzi^IV

^ICNP-Hortaliças/EMBRAPA, Caixa Postal 07.0218, 70359 Brasília, DF, Brasil. Send correspondence to J.V.V.
^IIDepartamento de Fitotecnia, ^IIIDepartamento de Zootecnia, and ^IVDepartamento de Matemática, Universidade Federal de Viçosa, 36570 Viçosa, MG, Brasil

ABSTRACT

The genetic structure of four populations of carrots was studied for resistance to leaf blight.
this character. The following parameters were estimated from half-sib progenies of each population: broad sense heritability (45.6 to 81.9%), expected response to selection as a percentage of the mean (7.0 to 28.1%), additive genetic variance coefficient (7.0 to 18.0%), and the ratio between the genetic and environmental coefficient of variation. In addition, there was a tendency of this character to showa greater phenotypic than genotypic variance with increased plant age. Seventy days after sowing is suggested as the best time to evaluate progenies for resistance to leaf blight in carrots.

Keywords: Heritability; Leaf blight; Carrot; Daucus. carota.

REFERENCES

Brar, J.S. and Sukhija, B.B. (1981). Studies on genetic parameters, in carrot (Daucus carota L). J. Res. Punjab. Agric. Univ. 18: 287-291.

Casali, V.W.D., Pinto, C.M.F. and de Padua, J.G. (1984). Origem e botânica da cenoura. Informe Agropec. 10: 8-9.

Cockerham, C.C. (1963). Estimation of genetic variance. In: Statistical genetics and plant breeding (Hanson, W.D. and Robinson, H.F. eds.). Washington, National Academic Science - National Research Council, pp. 53-93.

Della Vecchia, P.T. and Reifschneider, F.J.B. (1983). Estimativa de herdabilidade de resistência à Alternaria dauci em cenoura. In: Congresso Brasileiro de Olericultura, 23, Rio de Janeiro, Resumos... Rio de Janeiro, Sociedade de Olericultura do Brasil, pp. 141.

Eberhart, S.A. (s.d.). Techniques and methods for more efficient population improvement in sorghum. Ames. USDA/Iowa State Universit^y. 14p. Anexo.

Falconer, D.S. (1964). Introduction to Quantitative Genetics. 3. ed. London, Oliver & Boyed, 365 p. Ikuta, H. (1971). Mel/viramento de cenoura (Daucus Carota L. var. saliva), 19p. (mimeo).

Panse, V.G. (1957). Genetics of quantitative characteres in relation to plant breeding. Indian J. Genet. 17: 318-328.

Reifschneider, FJ.B. (1980). Queima das folhas de cenoura, um complexo patológico. Fitopatol. Bras. 5: 445-446.

Vencovsky, R. (1978). Herança Quantitativa. In: Melhoramento e Produção de Milho. (Paterniani, E. and Viegas, C.P. eds.). Edição da Fundação Cargil, Vol. I.

Vieira, J.V., Buso, J.A. and Della Vecchia, P.T. (1979). Resistência a Alternaria dauci (Kuhen) Groves & Skolko em uma população de cenoura Kuroda. In: Congresso Brasileiro de Olericultura, 19., Florianópolis, SC. Resumos... Florianópolis, EMPASC, v.1 p.51-54.