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Coefficient of parentage and breeding of brazilian soybean germplasm

N.A. Vello; D.M. Hiromoto; A.J.B.V. Azevedo Filho

Instituto de Genética e Centro de Informática na Agricultura, ESALQ, USP, Caixa Postal 83, 13400 Piracicaba, SP, Brasil. Send correspondence to N.A.V.

ABSTRACT

A total of 2346 coefficients of parentage (f) were estimated among 69 soybean (Glycine max (L.) Merrill) cultivars. The f values ranged from 0 to 1: eight pairs of cultivars had f = 1; 106 pairs of cultivars had f = 0; and the remaining 2232 pairs of cultivars had f values higher than zero and lower than one. The mean and the standard deviation among 68 estimates of coefficient of parentage were calculated for each cultivar. Cultivar Ivorá had the lowest (f = 0.0443) and cultivar Hardee the highest (f = 0.2272) mean coefficient of parentage. Based on the overall mean of the 2346 coefficients of parentage (f = 0.1641), the Brazilian soybean breeding program may be considered to involve a population of relatively low effective size (N = 11 to 15) with two or three cycles of recurrent selection. Comparisons were made among the United States, Argentine, and Brazilian soybean germplasms. The applications of the coefficient of parentage in parental selection for quantitative characters and for enhancement of the genetic base of soybean germplasm were discussed.

Keywords: parentage; breeding; brazilian; soybean; germplasm.

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