Rudi et al. (1998) published the following primers for amplification of the rbcLX region in Cyanobacteria:
The same authors provide an additional primer designated for sequencing of Nostoc spp.:
O’Brien, H., Miadlikowska, J., and Lutzoni, F. 2005. Assessing host specialization in symbiotic Cyanobacteria associated with four closely related species of the lichen fungus Peltigera. European Journal of Phycology 40:363-378.
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Rudi, K., Skulberg, O.M., and Jakobsen, K.S. 1998. Evolution of cyanobacteria by exchange of genetic material among phyletically related strains. Journal of Bacteriology, 180: 3453–3461.