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MOLECULAR SYSTEMATICS OF THE GENUS UVULARIA AND RELATED TAXA BASED UPON rbcL GENE SEQUENCE DATA

ZABTA KHAN SHINWARI

Abstract: To elucidate the phylogeny of the endemic North American genus Uvularia and related taxa, the chloroplast gene rbcL was sequenced in all the 5 species of the genus. The rbcL sequence data of 12 other genera viz., Tricyrtis. Disporum. Prosartes. Streptopus. Clintonia, Polygonatum, Medeola, Gloriosa. Colchicum. Veratrum. Dioscorea and Scilla representing different orders of Liliflorae were also analyzed to assess phylogenetic relationships among genera.
The two sections of Uvularia (Uvularia and Oakesiela) differed from each other by 14-27 substitutions (100d = 1.03 - 2.01 substitutions per site) and species within section Uvularia (U. perfoliata and U. grandiflora) by 14 substitutions (100d= 1.11). Intra-sectional variation in Oakesiella was 8-18 substitutions i.e., 8 (100d=0.59, between U. floridana and U. sessilifolia) and 18 (100d = 1.33, between U. sessilifolia and U. puberula). Sequence data provided support for a monophyletic Uvularia comprising two subclades. One of these subclades is strongly supported and correspond to section Uvularia. A monophyletic group corresponding to section Oakesiella is also present in the shortest tree but is more weakly supported.
An analysis of Uvularia rbcL sequences together with other genera revealed that Disporum is the closest relative of the genus. The transfer of Tricyrtis. Streptopus and Clintonia to the Uvulariaceae from the Asparagates is discussed.

National Herbarium, National Agricultural Research Centre, P. D.NIH, Islamabad, Pakistan.