The value in hybrid combinations of inbred lines of corn selected from single crosses by the pedigree method of breeding
1940
Johnson, I.J. | Hayes, H.K.
1. In a study of single crosses between inbred pedigree method from single crosses, a comparison was made between their inbred-variety cross and single cross performance. 2. The evidence obtained from 12 single crosses between relatively low combining inbreds indicates that single crosses between low combiners may be expected to yield somewhat lower, on the average, than single crosses from relatively high combining inbreds when the single crosses are made between inbreds of diverse genetic origin. Single crosses between low combining inbreds with high combiners yielded as well, however, as single crosses between high combiners. The proportion of high yielding single crosses from low X high combiners was as good in this study as from high X high combiners. 3. Additional data from crosses between related inbred lines indicate that diversity in genetic origin is an important factor in obtaining the maximum expression of hybrid vigor. 4. From a comparison of 147 single crosses between inbreds of unrelated origin with recommended double crosses, 63, or 43%, yielded significantly higher than the double crosses used as a standard. These results indicate the desirability of selecting inbreds for use in double crosses from crosses between inbred lines that have superior characters, thus giving an opportunity to combine in a single inbred the desirable characters of its two parents.
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