Phylogenetic patterns and genetic diversity of Indian Tinospora species based on chloroplast sequence data and cytochrome P450 polymorphisms

Based on morphology, the species status and taxonomic affinities of three species of Tinospora (T. cordifolia, T. sinensis, and T. crispa) with ranges in India, have been questioned. To evaluate species delimitation and population structure among 40 accessions of the three species, a relatively new marker, cytochrome P450, was used. Five out of nine primers generated polymorphisms with 39 out of 47 bands polymorphic. The P450 binary data, when analyzed using distance methods, strongly supported the monophyly of each Indian species and were congruent with previous RAPD work. To further investigate the status of these species, we combined P450 and RAPD data. The resulting unrooted phylogram highly supports the monophyly of each species but with little population structure within each species. To understand the phylogenetic placement of the three Indian Tinospora species within Menispermaceae, chloroplast atpB and rbcL sequence data for a large sampling of the family were analyzed using likelihood and parsimony methods. The resulting phylogenies highly support the Indian Tinospora species as part of a clade (expanded Tinosporeae), consisting of diverse Menispermaceae from around the world. The three Indian species are monophyletic and are most closely related to Tinospora species from Australia (T. esiangkara and T. smilacina).