Full text in pdf format

Analise de trilha e divergencia genética de cultivares e clones de batata-doce (Path analysis and genetic divergence among cultivars and clones of sweet potato)

Joao Eustáquio Cabral de Miranda^I; Cosme Damião Cruz^II; Albano Salustiano Pereiras^I

^ICNPHortaliças/EMBRAPA, Caixa Postal 07.0218, 70359 Brasilia, DF, Brasil. Enviar correspondência para J.E.C.M.
^IIDepartamento de Biologia Geral, Universidade Federal de Viçosa, 36570 Viçosa, MG, Brasil

ABSTRACT

Sweet potato (Ipomoea batatas (L.) Lam) breeding program at the Brazilian National Vegetable Research Center (CNPH) is geared towards developing orange, dry-fleshed cultivars, while maintaining genetic variability within germplasm pools. At present, most of the Brazilian sweet potato cultivars have white or cream-colored flesh. The objective of this research was 1) to evaluate direct and indirect effects (path analysis) of physio-chemical characteristics on the mean weight of sweet potato roots, 2) to evaluate genetic divergence among 18 orange-fleshed cultivars and clones, and 3) to estimate canonical correlations between two groups of variables. The first group of variables included weight, length and width of roots, and the second group of variables was comprised of the physio-chemical characteristics in percentage of total solids, soluble solids (brix), protein, starch, total sugars, fiber and ash. Canonical correlations indicated that total solids and soluble solids were highly associated with root weight. Highly positive effects resulting from path analysis confirmed the significant relationship between total (and soluble) solids and the mean weight of the roots. Genetic divergence among orange- fleshed sweet potato genotypes was considerable. The genotypes BDI 021, BDI 062, BDI 094 e BDI 116 could be used for polycross breedirg method with white and cream-fleshed sweet potatoes. This method assures an ample genetic base for the long term objectives of the sweet potato program at CNPH.

Keywords: genetic; divergence; cultivars; clones; sweet potato.

REFERENCES

Anand, I.J. and Rawat, D.S. (1984). Genetic diversity, combining ability and heterosis in brown mustard. Indian J. Genet. 44: 226-234.

Association of Official Analytical Chemists. Washington, USA. (1980). Official methods of analysis of the Association of Official Analytical Chemists. 13rd edn. Washington, D.C., 1018 pp.

Cereda, M.P., Wosiack, G. e Conceição, F.A.D. (1984). Avaliação físico-química e reológica de vinte e seis cultivares de batata-doce (Ipomoea batatas (L.) Lam). Hort. Bras. 2: 6-12.

Dunteman, G.H. (1984). Introduction to multivariate analysis. Beverly Hills, Sage publications, 237 pp.

Huang, S.P., Miranda, J.E.C. and Maluf, W.R. (1986). Resistance to root-knot nematodes in a Brazilian Sweet potato collection. Fitopatol. Bras. 2: 761-767.

Li, C.C. (1975). Path Analysis - a Primer. Boxwood, Pacific Grove, 346 pp.

Maluf, W.R., Ferreira, P.E. and Miranda, J.E.C. (1983). Genetic divergence in tomatoes and its relationship with heterosis for yield in F₁ hybrids. Rev. Brasil. Genet. 3:453-468.

Miranda, J.E.C. de, França, F.H., Carrijo, O.A. e Souza, A.F. (1987). Batata-doce (Ipomoea batatas L.) Lam). Brasília, EMBRAPA-CNPH, 13 pp. (Circular Técnica, 3).

Miranda, J.E.C., França, F.H., Canijo, O., Souza, A.F. e Aguillar, J.A.E. (1984). Cultivo de batata doce (Ipomoea batatas (L.)Lam.) EMBRAPA-CNPH, Brasília, 8 pp. (Instruções Técnicas, 7).

Pereira, A.S. (1987). Caracterização físico-química de cultivares de batata-doce (Ipomoea batatas (L.) Lam.). In: Congresso Brasileiro de Ciência e Tecnologia de Alimentos, São Paulo, SP, pp.78.

Rao, R.C. (1952). Advanced Statistical Methods in Biometrical Research. John Wiley, New York, pp. 390.

Ribeiro Filho, J. (1967). Cultura da batata-doce, Viçosa, Imprensa Universitária, 99 pp.

Shamsuddim, A.K.M. (1985). Genetic diversity in relation to heterosis and combining ability in spring wheat. Theor. Appl. Genet. 70:306-308.