Systematic position of Rivina humilis var. humilis, R. humilis var. bracteata and R. bengalensis based on nrDNA ITS and cpDNA rbcL & trnH-psbA sequence data

Abstract

The ITS and cpDNA sequences were obtained for three taxa of the family Phytolaccaceae, viz. Rivina bengalensis S.C.Srivast. & T.K.Paul, R. humilis L. var. humilis, and R. humilis var. bracteata D.Maity, Sonia Mitra, Manasi Mandal & Maiti. The MLtree strongly supports the Rivina humilis clade, which includes R. bengalensis and R. humilis var. bracteata. The synonymization of R. bengalensis is supported by both molecular and morphological data. The accessions of Rivina humilis var. bracteata group together in the R. humilis clade, but the results also show inter-population variation, which primarily supports the varietal status of the taxon. The broadly oblanceolate bracts which is abruptly narrowed from middle or above middle into a long subulate to narrowly triangular, acuminate apical lobe make the variety distinct from typical R. humilis. The combined rbcL and trnH-psbA dataset reveal congruent result for the sequenced Rivina spp. Present study is the first report on molecular systematics of R. humilis from India.