Inheritance of multiple transgenes in wheat

Understanding and predicting transgene linkage relationships is required to utilize efficiently transformation technologies in breeding programs. This study was conducted to determine the co-transformation frequency of three gene sequences by means of a three-plasmid co-transformation system and to determine the mode of inheritance for two genes of interest. Twenty-five in dependently transformed wheat (Triticum aestivum L.) plants were produced b y microprojectile bombardment of 1080 immature embryos with a three-plasmid system. Polymerase chain reaction (PCR) analyses of T-1 progeny from each of the 25 T-0 plants indicated co-transformation of all three plasmids at a frequency of 36%. Two of nine transgenic families containing all three pla smids were characterized for the segregation of the two genes of interest i n T-1, T-2, and T-2 testcross generations by PCR. These data suggest that t he two genes of interest are linked in both families studied. On the basis of the inheritance of the two genes of interest, one transgenic family woul d be desirable for use in a breeding program because it contained tightly l inked genes, whereas the other family studied would not be desirable for us e in a breeding program because the two genes segregated aberrantly.