TRAP markers generated with resistant gene analog sequences and their application to genetic diversity analysis of radish germplasm.

摘要

TRAP is a novel molecular marker technique which has been effectively used in genetic diversity analysis of germplasm and genetic mapping. However, it has not yet been applied to radish. In this study, novel TRAP markers based on expressed sequence tag (EST) and resistance gene analog (RGAs) were developed and applied to the genetic diversity analysis of radish genotypes. With data-mining method, a total of 50 RGAs including 35 unigenes and 15 singletons were identified from the public sequence databases and employed to design the fixed primers of TRAP markers. Fifty-nine RGA-derived fixed primers were combined with five arbitrary primers, and these TRAP primer combinations were tested in two genotypes ('NAU-YH' and 'NAU-DY'). Furthermore, 65 TRAP primer combinations were selected for genetic diversity analysis and 385 polymorphic fragments were produced among 30 radish genotypes. Dendrograms constructed by UPGMA method showed that these genotypes could be clustered into four groups. Interestingly, these groups were in highly accordance with the results of resistance evaluation to Turnip Mosaic Virus (TuMV). A cultivar identification diagram (CID) was made manually to discriminate the 30 radish genotypes using four polymorphic TRAP primer combinations. The results indicated that TRAP is an efficient genetic marker system, which could provide an effective tool for genetic mapping and for marker-assisted selection in radish breeding programs.Digital Object Identifier http://dx.doi.org/10.1016/j.scienta.2013.07.004