Identification of translocations in pea by in situ hybridization with chromosome-specific DNA probes

Abstract

Biotin-labelled DNA probes for tandemly repeated sequences have been used in in situ hybridization experiments as chromosome-specific markers in pea. Six of the seven chromosome pairs can be marked at single sites in this way. Translocations from a standard karyotype are revealed as chromosomes that have two hybridization sites, rather than one. By probing a tester set of reciprocal translocation (or interchange) lines, some of the markers can be assigned to chromosomes. The method is rapid and simple and, in the absence of well-resolved chromosome bands, provides a means for clarifying some of the problems in pea cytology.Key words: in situ hybridization, translocations, chromosome markers.