6. Use of translocations in corn breeding. Once any significant gene for an economic trait is located, it should be possible to transfer that gene to any commercial inbred line with only a minimum of alteration of the inbred line itself. In simplest form, the inbred line would first be crossed with the proper translocation (one near the locus of the gene). The F1 would then be backcrossed recurrently to the inbred line selecting always the semisterile plants. Then on selfing, the homozygous translocation inbred can be isolated. The next step consists of crossing the translocation inbred with the desired gene, and backcrossing to the translocation inbred. Then, on selfing and eliminating the translocation, the result should be essentially the inbred line homozygous for the desired gene. The length of time required is considerable, but can be reduced by various shortcuts. No great number of plants need be grown, nor is much labor required. And an economic gene could be transferred to any number of inbred lines simultaneously. This method is suggested only for such traits as are difficult to follow, such as for example resistance to disease, insects, drouth or cold. It is essentially an indirect method, which controls the valuable but difficult character by substitution of pollen semisterility which can be easily and precisely followed.

E. G. Anderson