Mapping and stability of QTLs for seed weight in common beans under different environments

The objectives were: 1 - to identify, under different environments, RAPD markers linked to loci that control the 100 seed weight of common beans; 2 - to evaluate the existence of interactions involving QTLs with planting dates and locations; 3 - to compare detection procedures of markers linked to QTLs utilizing the methods of mapping and multiple regression. One hundred and ninety-six recombinant inbred lines derived from the cross of cultivars Carioca x Flor de Mayo were evaluated under two traditional sowing dates for common beans in 1996, 1997 and 1998, in Lavras and Patos de Minas, Brazil. For the phenotypic evaluation of the families, seven field experiments were conducted. The experimental design used was a 14 x 14 partially balanced Square Simple Lattice. Results indicated that interaction of QTLs by location were significant, and some stable QTLs were identified. Multiple regression analysis identified a greater number of QTL-linked markers than the process of composite interval mapping. There was no coincidence between results obtained with the two methods studied. Molecular markers which were considered of greater potential use on marker- assisted selection for seed weight were OPN-02 (1445 pb) e OPM-06 (1096 pb).