ABSTRACT
This study deals with morphological characterization, determination of photosynthetic pigments, and testing of antibacterial activities of 10 Piper genotypes from Andaman and Nicobar Islands. Results revealed significant differences among the genotypes under study. Plants of P. colubrinum-2 had longer, heavier leaves and higher petiole thickness, while that of P. sarmentosum-3 had broadest leaves and widest petioles. Dry matter content of the genotypes varied from 18 to 40%. Total chlorophyll content in the leaves varied from 0.60 to 6.72 mg/g. Wide variations were also observed in antibacterial activity of ethanolic extracts of genotypes at two doses (80 and 100 µL) against seven bacterial pathogens. P. colubrinum-1 and P. colubrinum-2 were effective in inhibiting the growth of Staphylococcus aureus and results were comparable with positive control. In case of Pseudomonas fluorescens, extracts of all genotypes were effective as their zone of inhibition was found to be statistically on par with the control chloramphenicol. Although moderate level of inhibition was observed for rest of the pathogens, yet it remained much lower than the inhibition observed for positive control. Authors affirm that while working on a new species, chance screening of an ineffective genotype may completely eliminate the candidature of that species for further experiments. Hence, while screening any new species for its antimicrobial potential, using the available intraspecific diversity of that species can help in ascertaining the actual potential of the species and identification of superior types as observed in this research.
