Comparação de métodos de condução de populações segregantes do feijoeiro

Abstract

COMPARISONS AMONG METHODS TO CONDUCT SEGREGATING BEAN POPULATIONSABSTRACT -The efficiency of five methods of conduction of segregating populations was compared in common beans. For this experiment, the segregating population from cross between the cultivars Carioca and Flor de Mayo was used. The methods pedigree, bulk, single seed descent (SSD), F 3 derived bulk and F 2 derived bulk were conducted as established for each method. They were evaluated in two locations, Lavras, in the south of Minas Gerais, and in Patos de Minas, located in the Alto São Francisco region. Utilizing a 18 x 18 triple lattice design, 320 families were evaluated, with 64 being derived from each method, with the parents and two other checks. Estimatives were obtained from genetic and phenotypic parameters for grain yield data (g/plots). The main criteria utilized to compare the breeding methods were the average performance of the families, the expected response with different selection intensities, and the number of families in each method with superior performance to a particular standard. There were no significant differences between the methods to obtain the superior families, that is, if correctly conducted, all the methods enable similar success with the selection. Considering the estimatives of the genetic and phenotypic parameters, together with the ease and flexibility of conduction, the bulk and SSD method proved to be the most advantageous.

Allele frequency and selection efficiency in cross populations of Andean x Mesoamerican common beans (Phaseolus vulgaris L. Fabales, Fabaceae)

“…Nevertheless, several reports on the heritability estimate of the number of days to the beginning of P. vulgaris flowering were found in the literature that confirm that the h 2 of this trait is normally high (Arriel et al, 1990;Nunes et al, 1999;Abreu et al, 2005;Silva et al, 2007). For grain yield, h 2 estimates for P. vulgaris progenies of similar magnitudes to those found by us are commonly found in the literature (Raposo et al 2000;Cunha et al, 2005;Londero et al, 2006). However, no tendency was observed in the heritability values caused by the alteration in the allele frequencies of the populations (Table 2).…”

Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

“…Raposo et al (2000) also observed more variation in grain yield among lines with high levels of endogamy obtained under the SSD method. This may occur because selection in the greenhouse is not carried out in the SSD method, so the higher genetic variability obtained in the F 2 generation is preserved in segregating generations if lines are not lost because of germination problems.…”

“…A method for selection of segregating populations will be more efficient if the magnitude of genetic gain for the same selection differential is higher (Raposo et al, 2000). Therefore, in addition to the lines' mean performances, the probability of higher gain should be considered when choosing the method of selection.…”

Perspectives for the Use of Quantitative Genetics in Breeding of Autogamous Plants

“…Among them, the bulk method within progenies F 2 or F 3 [6] and the single seed descendent (SSD) [7][8][9] have also been widely used. Comparisons among these methods have been performed over time and, although in some cases differences have been detected among them [10][11][12], what is observed is that if they are well applied, all of them are efficient.…”