Foundation Populations for Adapted by Exotic Crosses
1987
Bridges, W. C. | Gardner, C. O.
Introgression of exotic germplasm into adapted breeding populations is needed to reduce problems of genetic vulnerability and selection plateaus. Our objective was to determine whether the F₂ or the first backcross to the adapted population (BC₁) was the better foundation population in which to begin selection. Selection response was calculated in the foundation populations based on two different additive genetic models. The calculated selection responses were then used to compare the F₂ and BC₁. Results of the comparisons indicate (i) the F₂ is better for both long-term and short-term selection goals when the adapted and exotic populations perform the same, (ii) the BC₁ is better for short-term goals when the adapted population is superior, (iii) the BC₁ is better for long-term goals when the adapted population is superior due to a greater number of loci with favorable alleles present, and (iv) the F₂ is better for long-term goals when the adapted population is superior due to the presence of favorable alleles at loci with large effects.
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