Evaluation of an Indian germplasm collection of the medicinal plant Bacopa monnieri (L.) Pennell by use of multivariate approaches

Twenty seven accessions of Bacopa monnieri collected from semi-temperate, subtropical and tropical environments at geographically distinct locations in India were examined for genetic variability carried in them at Lucknow, India in a semi-temperate environment. The accessions were grown in earthen pans, arranged in completely random block design, replicated four times, and observed for 13 qualitative and 24 quantitative characters, including bacoside-A content of herbage. On the basis of principal component and canonical variable analyses, the accessions could be grouped into seven clusters, of 2 to 6 accession sizes. The metroglyph analysis using five qualitative traits, cluster analysis and dendrogram drawn using D-2 data separated the clusters IV and V and cluster VII from all the others. The bacoside-A content of the herbage was found to be usually low in clusters of accessions possessing vigorous vegetative growth such as in cluster VII. It was also observed that some of the clusters included accessions having wide geographical origins. It was inferred that both the gross agroclimatic environment of a region and microenvironment in the vicinity of water bodies where a Bacopa monnieri genotype occurred must have interacted for the natural selection of the concerned genotype.