Para identificar QTLs para produtividade de grãos e peso de 100 sementes em feijoeiro (Phaseolus vulgaris L.), foram usados microssatélites influenciados pela seleção natural, identificados na população derivada do cruzamento 'Carioca MG' x 'ESAL 686', conduzida pelo método da população até a geração F24. Foram avaliadas 107 linhagens da geração F8 e 107 da F24 em três épocas distintas: inverno de 2001 (F8:9 e F24:25) em Ijaci; águas de 2001 (F8:10 e F24:26) e secas de 2002 (F8:11 e F24:27) ambos em Lavras. Utilizou-se o delineamento látice simples 18 x 18 em Ijaci, e triplo nas duas outras épocas. Entre os 105 pares de primers utilizados, 30 foram polimórficos nos genitores e no bulk de DNA das linhagens F24 e utilizados, juntamente com as avaliações experimentais, na análise de regressão linear múltipla - Stepwise. Foram identificados sete QTLs para a produtividade de grãos em F8 e seis QTLs em F24, sendo o marcador derivado do 'ESAL686' (BM156) o que exibiu maior efeito para aumentar a produtividade. Para peso de 100 sementes foram identificados cinco marcadores em F8 e dois em F24, todos provenientes do genitor 'ESAL686' e o que contribuiu com o maior peso foi o X61293. A maioria dos QTLs se expressou em um só ambiente.

Aiming to identify QTLs for grain yield and for 100 seed weight of common bean (Phaseolus vulgaris L.), microsatellite markers (SSR) affected by natural selection were selected in a population derived from the cross 'Carioca MG' x 'ESAL 686', advanced by the bulk breeding until F24. One hundred and seven F8 lines, and 107 F24, were evaluated in three environments: Winter of 2001 (F8:9 and F24:25) at Ijaci county; spring/summer of 2001 (F8:10 and F24:26) and summer/fall of 2002 (F8:11 and F24:27), both at Lavras county. Simple lattice 18 x 18 experimental design was used at Ijaci, and triple lattice in the others environments. Thirty polymorphic pair of primers were selected among 105, through the parents and a bulk of the F24 lines. The molecular and the experimental data were used in the multiple linear regression analysis (stepwise). Seven QTLs for grain yield were identified in F8 and six in F24, and the BM156 marker (derived from 'ESAL 686') showed the major effect. For 100 seed weight five QTLs were identified in F8 and two in F24, all of them derived from 'ESAL 686', and the major effect was exhibited by X61293 marker. Most of the QTLs expressed in only one environment.

A segregant bulk population derived from a single cross between the Carioca MG cultivar and the ESAL 686 line was used to investigate whether the action of natural selection in the direction required by the breeders and the delaying line extraction would increase the chance of obtaining families with greater grain yield. The populations were advanced from F2 to F24 and obtained families F2, F8 and F24 from the plants. These families and their parents were assessed for grain yield (kg/ha) in Lavras-MG in three sowing seasons (July 2001, November 2001 and March 2002) in an 18 x 18 lattice design with two replications in the first sowing and three in the other two. The largest mean yield, regardless of sowing season, was among the families derived from the F24 plants. The frequency of superior families increased when line extraction was delayed to more advanced generations.