Fruit morphology helps identifying evolutionary groups in Alpinieae (Zingiberaceae): inferences from phylogenetic analysis of gingers in Sri Lanka

To assess the systematic and the phylogenetic placement of the members of the two important genera Alpinia Roxb. and Amomum Roxb. in Sri Lanka, molecular data of twelve in-group species together with three out-group taxa of the family Zingiberaceae were extensively analysed for phylogenetic significance. The current analysis of the evolutionary relationships of the Sri Lankan members of the genera of interest, utilising DNA sequence data of the chloroplast genome regions trn L-F and trn S-fM, has resolved four groups of Alpinia and two major clades of Amomum with substantial parsimony analysis and Bayesian inferences consistency values. With new accessions from the entire native range of the family, this result points to the need of an inevitable re-circumscription of the genus Alpinia, and shows congruence to the recent reshuffling of the genus Amomum and the family Zingiberaceae, except for the placement of each genus as monophyletic groups in the context of our study. This study suggests swapping the group defining species of an Alpinia clade observed in previous studies and the use of fruit morphology to distinguish among recognised groups for Sri Lankan species as they exhibit positive correspondence.