Full Length Research Paper

Phylogenetic relationships of eleven Kobresia accessions from the Tibetan plateau

Peizhi Yang¹, Hongmei Zheng¹, Steven Larson², Yanjun Miao¹ and Tianming Hu¹*

¹Department of Grassland Science, College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, Shaanxi, 712100, P.R. China.

²Forage and Range Research Laboratory, Utah State University, USDA-ARS, Logan, Utah, 84322-6300, USA.

*Corresponding author. E-mail: hutianming@126.com. Tel: +86 13709124728.

Abbreviations: RAPD, Random amplified polymorpfhic DNA; AFLP, amplified fragment length polymorphism; GIS, geographic information system; CTAB, cetyl trimethy-lammonium bromide; PCR, polymerase chain reaction; PIC, polymorphism information content; ITS, internal transcribed spacers; PPB, percentage of polymorphic bands.

Accepted 14 May, 2010

   Abstract

In the past, identification of the genus Kobresia was mostly dependent on morphological characteristics. This study used random amplified polymorphic DNA (RAPD), sequences of nrDNA ITS, cpDNA trnT-L-F spacer and cpDNA ndhF to assess the phylogenetic relationships among the accessions of Kobresia plants collected from the Tibetan plateau. In the dendrograms, Kobresia macrentha (L) species formed a separate clade suggesting a remote relationship with other accessions. These trees showed that species found in similar habitats or having similar adaptations tended to cluster together. Thus, the genetic variation and adaptation seen in these Kobresia accessions may be due to their remote geographic and high altitudinal position in the Tibetan plateau. This study highlights the importance of molecular analysis in understanding the genetic diversity and structure of Kobresia accessions, and contributes to the knowledge of conservation of genetic resources.

Key words: Kobresia, phylogenetic relationships, random amplified polymorphic DNA, Tibetan plateau.