Phylogenetic insights into the endemic species of the genus Senecio L. (Asteraceae) in India
ID: 613 / 410
Proposed Symposium Title: Phylogenetic insights into the endemic species of the genus Senecio L. (Asteraceae) in India
Akanksha S. Jeswani1, Siddharthan Surveswaran2, Manoj M. Lekhak1
Affiliations: 1 Shivaji University, Kolhapur, India 2 University of Hyderabad, Hyderabad, India
Senecio L. (Senecioneae: Asteraceae) is one of the most speciose genera globally, comprising approximately 1250 species primarily concentrated in southern Africa and South America. The genus is characterized by its remarkable adaptability to varied habitats which is probably the reason for its widespread distribution and high species numbers. The sheer magnitude of species and huge variation has hindered comprehensive phylogenetic reconstruction. For a long period of time phylogenetic studies have revealed the paraphyletic or polyphyletic nature of the genus prompting the need for better sampling as well more sequence markers. However, despite extensive molecular studies on Senecio worldwide, the Indian species have remained largely unexplored. In India, the genus is represented by about 53 taxa (47 species and 6 varieties), exhibiting high species diversity in the Himalayas and the Western Ghats. Of the 21 endemic species identified in India, 80% are confined to the Western Ghats. We sampled six species and two putative new species from the northern Western Ghats to study their phylogenetic status. Based on different nuclear ITS and plastid markers (trnT-L, trnL, trnK, psbA-trnH), the analysis reveals that these taxa belong to the Faujasia-Bethencourtia clade, as identified in Pelser et al. (2007). The Indian species are monophyletic with sister species from sub-Saharan Africa with the exception of S. scandens which is distributed in southeast Asia. The results indicate a radiation of the genus in peninsular India after dispersal from Africa.