Studies of Genetic Diversity in the Seed Raised Population of Withania Somnifera (L.) Dunal using RAPD Markers

Abstract

Withania somnifera (L.) Dunal is one of the important medicinal plants having immense therapeutic value. It is mainly known for its bioactive compounds withanolides present in the roots. The aim of the present study is to study the genetic diversity among the wild seed raised population of W. somnifera from Thapar Institute of Engineering and Technology (Patiala) using RAPD molecular markers and morphological markers. Morphological data showed good variations among the plants studied. The RAPD markers revealed much more information. A total of 15 RAPD primers were selected on the basis of those produced clear and good amplification. In total, 89 markers were scored. In which 77 markers were observed as polymorphic (86.52%) and 12 markers were monomorphic (13.48%). The size of amplified fragments was ranged between 250 to 6000 bp. The similarity indices were calculated using Jaccard’s similarity coefficient which ranged from 0.383 to 0.695. The cluster analysis by UPGMA (unweighted pair group method with average) formed two clusters. In one cluster, only two accessions were grouped (WS 9 and WS 12) whereas, in another cluster two subgroups were generated consisted of 10 accessions. The highest percentage of polymorphism (100%) was seen with RAPD 3, RAPD 10, RAPD 11, RAPD 16, RAPD 1 and RAPD 32 and, lowest percentage of polymorphism (60%) was noticed with RAPD 7. The highest PIC value was generated by RAPD 7 which was 0.400 and the least value was observed with RAPD 1 i.e., 0.159. High genetic diversity was revealed by RAPD primers among all the accessions of W. somnifera.