Analysis of phylogenetic relationships in Abelmoschus species (Malvaceae) using ribosomal and chloroplast intergenic spacers

Abstract

India is an important centre of diversity for genus Abelmoschus belonging to family Malvaceae and about eight Abelmoschus species occur here. In the present study the phylogenetic relationships among A. caillei, A. crinitus, A. esculentus, A. ficulneus, A. moschatus, A. tuberculatus, A. tetraphyllus and A. pungens were analysed using modern phylogenetic tools such as nuclear ribosomal spacers (ITS-1, ITS-2) and chloroplast intergenic spacers (trnC-trnD, trnE-trnF, trnH-psbA)to estimate species divergence based on sequence similarity. The study exposed the lack of power of ribosomal spacers ITS- 1and ITS-2 in resolving the species relationships in complex polyploid genera like Abelmoschus while the analysis of cpDNA intronic spacers revealed that A. ficulneus and A. moschatus are the closest wild relatives of A. esculentus. The study was helpful in redefining the Abelmoschus gene pool and since these species are exclusively found in the Indian sub continent, the centre of origin of okra should be re-addressed properly.