Analysis of Genetic Diversity in Astragalus rhizanthus Benth. ssp. rhizanthus var. rhizanthus (Fabaceae) Using Molecular Markers from India

Abstract

Astragalus rhizanthus with three infraspecific taxa (i.e., A. rhizanthus ssp. rhizanthus var. rhizanthus, A. rhizanthus ssp. rhizanthus var. pindreensis, and A. rhizanthus ssp. candolleanus) is widely scattered in the Himalaya from Jammu and Kashmir to Uttarakhand provinces in India. Among them, A. rhizanthus ssp. rhizanthus var. rhizanthus exhibits enormous morphological diversity throughout its range of distribution. An assessment of genetic diversity studies was undertaken to understand the level and pattern of diversity, using Inter simple sequence repeats (ISSR), Random amplified polymorphic DNA (RAPD) and Directed amplification of minisatellite DNA (DAMD) profiles. Fifteen ISSR, 18 RAPD and 6 DAMD primers were used to unravel the diversity among 20 genotypes collected from the known localities in the Indian Himalaya. A total of 242 bands from ISSR, 352 from RAPD and 142 from DAMD were obtained with an average of 92.23% polymorphism in the species. Pair-wise genetic similarity for the cumulative data was determined using Jaccard's similarity coefficient which varied from 0.19 to 0.84. A combined UPGMA dendrogram was generated which revealed that different genotypes exhibited their affinity according to their geographical distribution. Tree topology suggests the existence of two distinct groups of the genotypes. Gene diversity (H) and Shannon's information index (I) were estimated and these values were found higher in the genotypes collected from Jammu and Kashmir than Himachal Pradesh.