Assessing genetic relationships among coconut (Cocos nucifera L.) accessions using inter simple sequence repeat markers

Thirty-three coconut accessions from a world-wide coconut collection at the International GeneBank in India were analyzed using inter simple sequence repeat (ISSR) markers with 19 primers flanking the simple sequence (microsatellite) repeat regions. Total of 199 ISSR markers were scored, of which 154 were polymorphic. These markers were used to estimate the genetic similarity among accessions using Jaccard's similarity coefficient. Similarity matrix was used to construct a dendrogram and principal coordinate plot to show genetic relationships among accessions. Similarity values ranged between 0.526 and 0.855 and the least similarity was found between Nicobar tall (NICT01) and chowghat orange dwarf (COD). In the dendrogram and principal coordinate plots, coconut accessions from Southeast Asia, South Asia and South Pacific formed separate groups and this grouping was generally in accordance with their origin and pattern of dispersal of coconuts from its centre of origin.