Genetic diversity and population structure of Dactylorhiza hatagirea (Orchidaceae) in cold desert Ladakh region of India.

Abstract

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure within and among nine natural populations of Dactylorhiza hatagirea, a critically endangered or rare terrestrial medicinal orchid in cold desert of Ladakh region. Out of the 177 bands generated from twenty random primers, 174 were polymorphic. The genetic diversity of D. hatagirea that was revealed by observed number of alleles (Na), expected number of alleles (Ne), Nei’s diversity index (H), Shannon’s diversity index (I), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPL). Pair-wise population genetic distances ranged from 0.05 to 0.23. Analysis of molecular variance (AMOVA) revealed that 57% RAPD of variability was partitioned among population. The Principal coordinate’s analysis (PCoA) and UPGMA supported the grouping of all 96 accessions of nine populations into four cluster groups. However, a moderate genetic differentiation among population was detected based on different measures (Nei’s genetic diversity analysis: Gst = 0.2538; AMOVA analysis: Fst = 0.254)