Surya Shekhar Das, Swati Das (Sur) and Parthadeb Ghosh
RAPD markers were successfully used to identify and differentiate all the five species of Acanthaceae found in the mangrove forest of Indian Sundarban, to assess the extent of interspecific genetic diversity among them, to reveal their molecular phylogeny and to throw some light on the systematic position of Avicennia. The dendrogram reveals that the five species under study exhibits an overall similarity of 60.7%. Avicennia alba and A. officinalis (cluster C1) have very close relationship between them and share a common node in the dendrogram at a 73.3% level of similarity. Avicennia marina and Acanthus ilicifolius (cluster C2) also have close relationship between them as evident by a common node in the dendrogram at 71.8% level of similarity. Acanthus volubilis showed 68.1% similarity with cluster C1 and 60.7% similarity with cluster C2. Our study also supported the view of placing Avicennia under Acanthaceae. Regarding the relative position of Avicennia within Acanthaceae, it was shown to be very close to Acanthoideae. In comparison to other species, A. marina showed most genetic variability, suggesting utilization of this species over others for breeding programme and as source material in in situ conservation programmes. Extent of genetic diversity was the lowest in Acanthus volubilis and therefore demands priority of this species in conservation programme to prevent extinction
