Previous molecular investigations into Rubus species diversity have yielded significant knowledge about species relatedness. However, little work has been focused at the cultivar level. Random amplified polymorphic DNA(RAPD)-PCR studies have successfully differentiated closely related cultivars. The ability to definitively distinguish blackberry and red raspberry cultivars based on other molecular methods could prove useful in many aspects of breeding and proprietary protection. In this study, the nuclear ribosomal DNA internal transcribed spacer regions (ITS) of six Rubus cultivars were sequenced. DNA sequencing revealed little genetic variation among blackberry cultivars, but revealed distinctions between blackberry and red raspberry cultivars. Analysis by maximum-parsimony and maximum-likelihood confirmed the small variation among blackberry cultivars, although cultivars Apache, Brazos, and APF-12 did organize a weak sub-cluster within the blackberry genotypes. However, ITS region sequences do not appear to differentiate among closely related blackberry genotypes for purposes of cultivar discrimination or plant patent protection.
Stafne, Eric T.; Clark, John R.; and Szalanski, Allen L.
"Nuclear Ribosomal ITS Region Sequences for Differentiation of Rubus Genotypes,"
Journal of the Arkansas Academy of Science: Vol. 57
, Article 24.
Available at: http://scholarworks.uark.edu/jaas/vol57/iss1/24