Abstract:
The genus Piper is represented in Sri Lanka by ten species of which three are endemics.
Piper nigrum L. (black pepper) and P. betle L. (betel) are the main crops that make the genus
commercially important and some species are used in traditional medicine. This study aimed
to reveal the interspecific relationships of selected Piper species based on the variation in
qualitative phytochemical screening and phenetic approach.
Piper nigrum L., P. betle L., P. longum L., P. chuvya (Miq.) C. DC., P. siriboa L., P.
sylvestre Lam. and P. zeylanicum Miq. were collected from natural habitats and from the
cultivations. The air dried leaves were powdered using a grinder and subjected to successive
extraction using petroleum ether, chloroform, ethyl acetate and methanol. All the extracts
were subjected to qualitative phytochemical tests. Anatomical studies were carried out by
observing epidermal peels and transverse sections of the fresh leaves and photomicrographs
were prepared.
The phytochemical screening confirmed the presence of tannins, flavonoids, terpenoids,
glycosides, alkaloids and phenolic compounds in all the species examined. Various types of
trichomes, glands and secretory cells were present in the leaves which indicates the richness
of secondary metabolites. Fourteen morphological and anatomical characters of leaves were
subjected to cluster analysis using PAST software to infer interspecific relationships.
According to the phenogram (Single linkage, Euclidean distance), P. longum, P. zeylanicum
and P. sylvestre were clustered to one group showing more similarities while P. nigrum, P.
chuvya, P. siriboa and P. betle were separated from the rest. Presence of non-glandular
trichomes, symmetry of the leaf base and leaf length were the most discriminating characters.
