Genome Analysis in Brassica Using RFLPs

Abstract

RFLP markers were used to analyse the genomes of B. oleracea and B. rapa [B. campestris]. Detailed linkage maps of RFLP loci were constructed and the markers used to dissect genetic control of complex morphological traits. Evidence for the presence of duplicated regions that do not span entire pairs of linkage groups and considerable chromosome rearrangement was obtained for B. oleracea. In the B. rapa map, conservation in the linkage arrangement of duplicated loci between pairs of linkage groups was more pronounced than for B. oleracea. Between the 2 species, 3 pairs of linkage groups had a single large tract of loci in common, but each of the remaining linkage groups included conserved regions present on 2 or 3 linkage groups in the other species. Analysis of genes controlling morphological variation revealed the number, linkage group position and magnitude of gene effects for trait loci related to flowering in both species. The organization of RFLP and trait loci within and between genomes has provided substantial information on the evolution of these species.