Molecular and cytological evidence of deletions in alien chromosomes for two monosomic addition lines of Brassica campestris-oleracea.
A series of RFLP and isoenzyme markers were followed in the progenies of 2 alien addition lines. One of the lines, carrying the C genome chromosome 4 as the alien chromosome, was surveyed for 6 markers. Of the plants carrying alien chromosomes, 54% displayed all the expected markers, whereas the rest had 1 to 5 markers missing. The second line for C genome chromosome 5 displayed a similar behaviour when surveyed for 3 markers. All 3 markers were transmitted together in 46% of the plants carrying alien chromosomes, whereas the rest carried only 1 or 2 of the markers. The loss of markers was associated with reduced chromosome size caused by deletions. The observed chromosome deficiencies permitted deletion analysis for a rough physical mapping and ordering of the markers on the 2 C genome chromosomes.