|Jarret, Robert - Bob|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/1999
Publication Date: 7/1/2000
Citation: Scheiber, S.M., Jarret, R.L. Robacker, C.D., Newman, M. Genetic relationships with rhondodendron l. section pentanthera G. Don based on sequences of the internal transcribed spacer (its) region. Euphytica, 2000. Scientific hort. (2000), 85: 123-135 Interpretive Summary: Relationships between 16 species of azaleas were examined using a technique that compares differences in the plants' DNA. Thirteen of the species that were examined are native to the Southeastern US. The remainder of the species were native to either the Western US, China, or Turkey. The composition of the DNA analyzed in the 13 species native to the Southeastern US was very similar and suggests that all 13 of these species might not actually be distinct species.
Technical Abstract: Genetic relationships among specimens of the 15 currently recognized species in Rhododendron L. section Pentanthera G. Don were derived from sequence comparisons of the internal transcribed spacer (ITS) region. Sequences of the entire ITS region including ITS1, ITS2, and the 5.8S subunit were generated by direct sequencing of polymerase chain reaction (PCR) amplified fragments. Rhododendron vaseyi A. Gray, Rhododendron section Rhodora (L.) G. Don was used as an outgroup. Aligned sequences of the 16 taxa resulted in 688 characters. The region contained 38 variable sites and 8 phylogenetically informative characters. A bootstrap analysis was performed and a dendrogram was constructed with MEGA. Divergence values among the taxa were extremely low ranging from 0.00 to 3.51 % and did not totally support previous taxonomic treatments of the section.