Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/7/2005
Publication Date: 10/7/2005
Citation: Wang, M.L., Mosjidis, J.A., Morris, J.B., Dean, R.E., Jenkins, T.M., Pederson, G.A. 2005. Molecular genetic characterization of crotalaria germplasm: Potential new crop for nematode control and nitrogen fixation. In: Proceedings of the Plant and Animal Genome XIV, January 14-18, 2006, San Diego, CA. p. 136.
Technical Abstract: The genus Crotalaria comprises a large number of species many of which have economic value. Some of the Crotalaria species could be used as new crop for nematode control and nitrogen fixation. An assessment of genetic diversity of the Crotalaria germplasm is lacking. Polymorphic expressed sequence tag – simple sequence repeat (EST-SSR) markers derived from Medicago and soybean were used to assess the genetic diversity of Crotalaria germplasm collection consisting of 26 accessions representing four species. A total of 130 bands were detected with a mean number of 4.64 alleles per marker. The accessions were classified into four main groups, each of which consisted primarily of the four species. Morphological observation also confirmed the genetic classification of the accessions. However, there were a couple of exceptions for the classification: one accession each from C. juncea and C. spectabilis, respectively were classified into the group mainly representing C. retusa. Morphological comparison confirmed that these two accessions were misnamed during curation or conservation and should belong to C. retusa. The phylogenetic analysis suggests that C. juncea is much closer to C. retusa and C. spectabilis than to C. pallida, and C. retusa is much closer to C. spectabilis than other species. Highly distinguishing markers are required to further classify accessions within C. juncea. Some amplicons from Crotalaria were sequenced and their sequences showed a high homology (with 89% sequence identity) to Medicago truncatula from which the EST-SSR primers were designed however, the simple sequence repeat (SSR) was completely deleted in Crotalaria. This is the first report of application of DNA markers on Crotalaria species.