Population Polymorphism Study Among Tulsi (Ocimum sp.) Ecotypes In Assam, India Using Morphological And Biochemical Parameters

The genus Ocimum, (family Lamiaceae ) , displays great variability. Prevalence of cross pollination, polyploidy and interspecific hybridization has complicated its taxonomy, making its systematic study difficult. This study investigated the morphological and biochemical variability among 18 ecotypes collected from different parts of the Assam state, India. Considerable diversity was found using all the approaches. The quantitative morphological parameters showed wide variability, not always co-relating with their geographical distances. The Euclidean distance ranged between 6.06 (between the closest accessions) and 59.00 (between the most distant accessions). Phylogenetic analysis divided the accessions into two major clusters sharing approx. 76% identity, and a minor cluster (with three accessions) sharing only approx. 65% identity with the other two. A great deal of diversity was found in the qualitative characters too; that divided the ecotypes into two to five groups.  The biochemical characters also revealed wide polymorphism; the distance varied from 1.690 to 58.574. Similar to the morphological characters, the biochemical parameters too did not always correlate with geographical distances. The phylogenetic mapping divided the accessions into two major clusters, sharing approx. 80% similarity. Further work will be needed to correlate the distance based on the morphological and the biochemical characters.