Development and linkage mapping of unigene-derived microsatellite markers in Brassica rapa L.

摘要

Brassica rapa plants are highly important as vegetables, sources of oilseeds and fodder crop. Here, we developed 450 unigene derived microsatellite (UGMS) markers in B. rapa using unigenes downloaded from the National Center for Biotechnology Information database. Of the 450 UGMS primer pairs, 428 (95.1%) produced repeatable and reliable amplifications of expected size in at least one parental line of B. rapa , and 70 UGMS markers gave 72 polymorphic loci between the two contrasting parental lines. Cross-species transferability analysis of these 70 polymorphic UGMS markers in five other cultivated Brassica species showed varying transferability rates ranging from 82.9% in B. nigra to 97.1% in B. juncea and B. napus , and overall 53 UGMS markers amplified targets in all five species. The B. rapa linkage map was constructed using the 72 UGMS polymorphic loci and 154 previously developed SSRs. The newly developed UGMS markers and linkage map in this study would help in future studies to better understand the organization and evolution of Brassica genomes with respect to unigenes, in addition to mapping, tagging and cloning of economically important trait QTL/gene(s) and marker-assisted breeding in Brassica crops.