Assessment of Genetic Diversity and Evaluation of Relatedness Through Morphological and Molecular Markers Among Medicinally Important Trees: Terminalia arjuna, T. bellerica, T. catappa and T. chebula

Terminalia trees are being over exploited because of their medicinal and economical importance leading to loss of valuable genetic resources. The study included morphological variation and characterization of genetic diversity at interspecific level. Genus Terminalia is a complex group having many problems associated with taxonomic identification. Morphologically T. arjuna can be distinguished from other species having winged fruits whereas the fruits of T. catappa are elliptical and tomentose. Fruits of T. chebula are provided with ribs while fruits of T. bellerica are without ribs. Thus different species of Terminalia can be distinguished by characteristic of fruits and sometimes by characteristic of leaves. For the first time comprehensive study was done for estimation and analysis of genetic variation through random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers. A total of 12 polymorphic primers (6 RAPD and 6 ISSR) produced 80 polymorphic bands with an average of 7.5 bands per primer. The average polymorphism was 87.97% and five primers were reported to produce 100% polymorphism. Dendrogram based on RAPD and ISSR data grouped four Terminalia species in two distinct clusters. Cluster-I comprised 2 species viz. T. arjuna, T. chebula, while cluster-II comprised two species T. bellerica and T. catappa. Clustering of species was altercating with previous morphological studies.