Efficiency of Early Selection for Yield Performance in Wheat

Selection for yield in early generations is difficult, mainly due to a shortage of seed. In the breeding company Fr. Strube the breeder uses three-way crosses and first selects for yield between F₂′-derived lines in the F₄′. The generations are called F₁, F₂′, etc., because the first generation is already segregating. The efficiency of this selection was checked in the F₅′ and F₆′. For this purpose F₃′-derived progenies, corresponding to poor and good yielding bulks in F₄′, were selected. In later generations the average yield of the group of strains with good yield in the F₄′ was 4 % (F₅′) and 3 % (F₆′) higher, respectively, than the mean of the strains with low yield in the F₄′. Strains with very low yielding potential can easily be discarded in the F₄′. The risk of discarding lines with a very high yield is minimal. Selection for yield in the F₄′ was as effective as in the F₅′. The importance of testing F₂′-derived bulks in the F₄′ is not only based on the assessment of yield but also on the possibility of reliable intensive selection through recording visual characters (height, resistance against diseases) in a second environment in parallel to the single plant progenies.