Abstract
In maize (Zea mays L.), meiotic segregation products of reciprocal translocations are well defined. The predictible meiotic behaviors and products generated by these interchanges allow them to be used as tools to gain basic information in cytogenetics, genetics, and plant breeding. In combining a classic reciprocal translocation with a single B–A chromosome from a tertiary trisomic B–A translocation stock, unique individuals with unusual chromosome karyotypes are generated. In cases where a B–A chromosome was present, the frequency of 3:1 disjunction within the ring of four was increased. In the case of T6–9(5454) + B–6Ld, cytological identification, via root-tip mitosis, was able to identify the specific tertiary trisomic products generated. These karyotypes are predictable and highly repeatable. Such karyotypes may have specific uses in chromosome mapping, chromosome dosage studies, or genetic or molecular investigations.Key words: reciprocal translocations, tertiary trisomes, interchange trisomes, B–A translocations, maize.