Characterization of the phenotypic diversity of tsiperifery (Piper spp.), the wild pepper from Madagascar under-studied in spite of its international fame

Abstract

Tsiperifery is a wild pepper found in the rainforests of Madagascar. It has many uses that are well-known to the Malagasy and its demand on the international market is growing. It is a liana of the genus Piper (Piperaceae). Its taxonomic position is particularly uncertain. At present, it is unclear whether the natural populations should be grouped into one or more species and whether the species correspond to the taxa described. This study was carried out in order to resolve this vagueness about taxonomy. To characterize phenotypic variability, morphometric analyses were performed on 179 individuals using 29 descriptors of the leaf, inflorescence and fructification. The morphological classification was performed using factor analysis of mixed data (FAMD) and hierarchical clustering on principal components (HCPC). The results showed that tsiperifery comprises four distinct morphotypes that probably do not all correspond to the described species. The main distinguishing characteristics of these morphotypes are related to the leaves shape and thickness of the limb, and to the fruit size, shape of the stipe and berries. These results should be completed with a study of genetic variability to provide the scientific basis for a taxonomic revision of the Piper genus in Madagascar. This will provide a solid tool to guide foundations for the protection and management of this important heritage.