Wetlands Ecology and Management 10: 355–362, 2002. 355  2002 Kluwer Academic Publishers. Printed in the Netherlands. Molecular phylogeny of mangroves VIII: Analysis of mitochondrial DNA variation for species identification and relationships in Indian mangrove Rhizophoraceae * M. Lakshmi, M. Parani, P. Senthilkumar and Ajay Parida M. S. Swaminathan Research Foundation, III Cross Street, Institutional Area, Taramani, Chennai 600 113, * India; Author for correspondence (e-mail: ajay@mssrf .res.in; e-mail: pmb@mssrf .res.in; phone: 191 -44 - 2541229 /2541698; fax: 1 91 -44 -2541319) Received 21 August 2000; accepted in revised form 1 December 2001 Key words: Mangroves, Mitochondrial genes, Phylogeny, RFLP, Rhizophoraceae Abstract Ten species belonging to four genera of the mangrove tribe Rhizophoreae found in the Indian subcontinent were analysed for species identification and genetic relationship using nine mitochondrial gene probes. RFLP pattern observed with 27 probe enzyme combinations the genera Rhizophora, Bruguiera, Ceriops and Kandelia differentiated these species into three classes of mitotypes with further resolution within them. Clustering of these mitotypes indicated that Rhizophora was more closely related to Ceriops-Kandelia than to the Bruguiera. Though the component species of each genus clustered together, a high degree of heterogeneity was observed among four species of the genus Rhizophora and three species of genus Bruguiera. The variation between two species of Ceriops was minimal. Species-specific profiles were observed for all the species in some probe-enzyme combination. Though the monotypic genus Kandelia shared a number of loci with genus Ceriops, it remained distinct. The putative parents of the naturally occuring interspecific hybrid in Pichavaram were reconfirmed to be R. apiculata and R. mucronata. The results are discussed with regard to the taxonomic and phylogenetic relationships between different species and genera of the tribe Rhizophoreae. Introduction on field difficult. Although these species are widely accepted as ecologically and economically important Rhizophoraceae is a small pan-tropical family with 16 components of mangrove vegetation and the tribe is genera and 120 species. Within the family three tribes recognized as a natural and discrete taxon (Van Vliet have been recognized. Tribes Macarisieae and Gynot- 1976); there has been lack of genetic information in rocheae, include inland genera and tribe them and the classification till recently was based only Rhizophoreae, solely comprises of mangrove speies. on morphological variations. Earlier genetic studies in Tribe Rhizophoreae, generally referred to as man- Rhizophoreae species had been restricted to only the grove Rhizophoraceae includes four genera viz., reports of somatic chromosome numbers (2n 5 36) in Rhizophora, Ceriops, Bruguiera and Kandelia. This all the species (Kumar and Subramanian 1988) and tribe exhibits characteristics of true mangroves in- isozyme analysis in a few species of Ceriops and cluding uniform viviparous condition, formation of Kandelia (Goodall and Stoddart 1989; Ballmert et al. pure stands and complete fidelity to the mangrove 1988; Sun et al. 1998). There has been no information habitat. Despite major differences in the floral charac- on non-morphological genetic attributes across all the ters, the ranges of characters overlap among different members of this family and also among the man- species within this tribe (Tomlinson 1986). All the groves per se until recently (Lakshmi et al. 1997, characters used for identification of different species 2000; Parani et al. 1997a, 1997b, 1998; Schwarzbach are quantitative and often make species identification and Ricklefs 2000).