Molecular phylogeny of mangroves VIII: Analysis of mitochondrial DNA variation for species identification and relationships in Indian mangrove Rhizophoraceae

Ten species belonging to four genera of the mangrove tribe Rhizophoreaefound in the Indian subcontinent were analysed for species identification andgenetic relationship using nine mitochondrial gene probes. RFLP patternobservedwith 27 probe enzyme combinations the genera Rhizophora,Bruguiera, Ceriops andKandelia differentiated these species into three classesofmitotypes with further resolution within them. Clustering of these mitotypesindicated that Rhizophora was more closely related toCeriops-Kandelia than to theBruguiera. Though the component species of each genusclustered together, a high degree of heterogeneity was observed among fourspecies of the genus Rhizophora and three species of genusBruguiera. The variation between two species ofCeriops was minimal. Species-specific profiles wereobserved for all the species in some probe-enzyme combination. Though themonotypic genus Kandelia shared a number of loci withgenusCeriops, it remained distinct. The putative parents of thenaturally occuring interspecific hybrid in Pichavaram were reconfirmed to beR. apiculata and R. mucronata. Theresults are discussed with regard to the taxonomic and phylogeneticrelationships between different species and genera of the tribe Rhizophoreae.