The objectives of this work were to complement the studies on the genetic control of soybean resistance to rust and to suggest a breeding methodology that allows the recombination and selection of soybean genotypes carrying major and minor genes for rust resistance. Six experiments were carried out in Londrina, PR during three growing seasons from 2005/06 to 2007/08 involving five parents and their derived F2, F3 and F4 segregating populations. A completely randomized design was used with single plant hill-plots. The proposed methodologies ware designed to overcome the difficulties breeders face while selecting for minor gene resistance in the presence of major genes. This is dealt with by breeding large F2, F3 and F4 segregant populations to improve the changes of the favorable gene combinations to appear and increasing genotype homozygosis under pathogen pressure to enhance the frequency of the favorable genotypes in the populations F5 populations. This will also increase the chances of superior F6 to appear from plant selection in the populations.
Phakopsora pachyrhizi; Glycine Max; breeding methods; disease resistance; soybean breeding
