Genetic variation in the endangered Indian sweet flag (Acorus calamus L.) estimated using ISSR and RAPD markers

• The results showed that genetic variation is low among accessions of A calamus.
• Genetic variation within a population revealed homogenous nature.
• The development of homozygosity due to the dominance of clonal propagation.
• Low variation may decrease the potential of populations to survive in environment.
• Genetic variation study will be useful in conserving morphologically same variants.

Sweet flag (Acorus calamus L.), is a critically endangered species of mountainous regions of India. In order to evaluate and preserve the endangered medicinally important plant Sweet flag. We investigated the variation by collecting the whole plant from different geographical regions. Genetic variability among 20 accessions of this species was assessed using random amplified polymorphic DNA (RAPD) (25 primers) and inter simple sequence repeat (ISSR) markers (17 primers).The results showed 33.7% of bands formed by RAPD markers and 63.7% for ISSR were polymorphic. The Shannon’s indices (I) and Nei’s genetic diversity (h) among all the accessions were estimated for RAPD and ISSR respectively at 0.58 (SD = 0.07), 0.57 (SD = 0.13) and 0.40 (SD = 0.06), 0.33 (SD = 0.11) respectively. The similarity coefficient ranged from 0.72 to 0.94. The results revealed that genetic variation is much low among accessions. Since genetic variation within collected accessions is homogenous, the pattern of low genetic diversity within the accessions specifies that they are monoclonal. Therefore, we proposed that studies of intraspecific variation could be utilized in the development of conservation strategies, by identifying appropriate units of A. calamus for conservation.