AFLP analysis indicates no introgression of maize DNA in wheat x maize crosses

Amplified fragment length polymorphisms (AFLPs) were used to follow the possible introgression of maize DNA into haploids of wheat as a side-effect of exploiting wheat x maize hybridization for haploid production. AFLPs were generated with 64 MseI/EcoRI and 64 MseI/PstI primer combinations, and the AFLP profiles of haploids were tested against those of maize and of the regular wheat varieties involved in the crosses. On average, 45.1 and 110.7 fragments were produced per assay with the MseI/EcoRI and MseI/PstI combinations, respectively. Different numbers of fragments were produced for wheat and maize: an average of 81 in the haploid, 80 in the wheat parent, and only 67.1 in maize. No evidence was found for introgression of maize into the wheat genome. Three unique AFLP fragments were detected in haploids, which were not present in the parental wheat genotypes. These 'novel' AFLP bands in the haploids could be caused by nucleo-cytoplasmic interaction in the hybrid zygote. Such instability in the wheat genome is defined as temporal, as it was not detected in further generations when colchicine-doubled progeny of the haploids was tested for the presence of polymorphic fragments.