Phylogeny and Population genomics of Sri Lankan Peppers

The genus Piper of family Piperaceae is pantropically distributed and areas of diversification are found in the Neotropics and Southeast Asia, however larger number of species are reported in the Neotropics. Genus Piper includes economically important species like Piper nigrum (black pepper), P. betle (betel leaves) and P. longum (Thippili). Of the three species black pepper plays an important role since it is one of the export commodity of Sri Lanka. There are ten species of Piper documented in the flora of Ceylon (volumeVI, 1987), namely P. nigrum, P. betle, P. longum P. sylvestre, P. zeylanicum, P. trineuron, P. siriboa, P.chuvya, P. hymenophyllum and P. walkerii.. Three species are endemic to Sri Lanka, namely P. zeylanicum, P. trineuron and P. walkerii. In this project we try to perform a big survey in the forest reserves as well as in wildlife sanctuaries to collect and identify all the wild species in order to revise the existing flora of Ceylon. The crown age of Piper is around 71 myr, and there is no information on the origin and diversification of the endemic Piper species of Sri Lanka. Molecular phylogenies available to date do not include the species of Sri Lanka. In order to estimate the origin of the endemic species of Sri Lanka, we will do an overall molecular phylogeny of the genus by sequencing our species and including these sequences to the available sequences of species from the Neotropics as well as other species from Genbank for the respective nuclear and plastid markers. The molecular phylogeny obtained will be complemented with a Next Generation RADseq data based phylogenomic tree. Genetic diversity of Piper nigrum (black pepper) will be evaluated by selecting local races from the wet and intermediate zones using the RADseq data. Genetically highly divergent races will be evaluated for their yield and piperin content. Percentage of bisexual flowers as well as their distribution across the flowering spike, which has an impact on the yield of pepper, will be estimated by 3D computed tomography.