Comparison of Early Generation Yield Testing and a Single Seed Descent Procedure in Wheat Breeding
- D. R. Knott and
- J. Kumar2
Two breeding procedures were compared in two spring wheat (Triticum aestivum L. em. Thell.) crosses. Both procedures were started from the same selected F2 plants in each cross. In one procedure, a single seed was taken from each F2 plant to produce the F3 generation, the process was repeated for the F4. The F5 lines were then produced from the seed of individual F4 plants (single seed descent method, SSD). In the second procedure, the F3 lines were yield-tested and a pedigree method followed in the F3 and F4 (YT method). Each F4 line was bulked to provide seed for a yield test in the F5. The F6 SSD lines and F5 YT lines were then compared in yield tests.
The mean yield of the YT lines was significantly higher in both crosses, mainly because there were fewer, very low yielding YT lines. The correlations between the F3 and F5 yields of the YT lines were significant in both crosses, but were not particularly large (0.29 and 0.14). The yield of the F5 YT lines, derived from the highest yielding 20% of the F3 lines, was compared with the highest-yielding 20% of the Fo SSD lines. In each cross, the SSD lines were at least as good as the YT lines. Although selection based on F3 yields would have had some effect, it is doubtful that it was worth the labor involved. The SSD procedure appears to have considerable meritPlease view the pdf by using the Full Text (PDF) link under 'View' to the left.
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