Molecular Characterization of Cinnamon (Cinnamomum Verum Presl) Accessions and Evaluation of Genetic Relatedness of Cinnamon Species in Sri Lanka Based on TrnL Intron Region, Intergenic Spacers Between trnT-trnL, trnL-trnF, trnH -psbA and nuclear ITS

Abstract

Cinnamomum verum is one of the most important spice species in Sri Lanka and it contributes to 70% of the world bark production. There are 9 Cinnamomum species found in Sri Lanka. Although it is a very important spice crop in Sri Lanka, the taxonomy of the species has a controversy. These species are identified by the floral, foliar morphology and pollen morphology, ecophysiological features, chemical and essential oil constituents and etc. A molecular technique to identify these species would greatly facilitate identification of species correctly. Genetic variation among species of Cinnamomum: C. verum, C. citriodorum, C. capparu-coronde, C. dubium, C. litseafolium, C. rivulorum, C. sinharajaense and C. camphora found in Sri Lanka was studied by analyzing nucleotide sequence of different cpDNA regions and an ITS region of the rDNA. The cpDNA regions studied were intergenic spacers between trnL-trnF, trnT-trnL, trnH-psbA and trnL intron. We were able to identify a number of variable sites for cpDNA sequences of trnL intron, trnL-trnF IGS, trnT-trnL IGS, trnH-psbA IGS and intergenic transcribed spacer (ITS) regions of rDNA. Although there is not much variations among the cpDNA regions we studied, it will contribute to the clarification of the genetic diversity of Sri Lankan Cinnamomum species which have never been studied at the DNA level. Although there is not much cpDNA variation and it did not provide much information for the taxonomy of Cinnamomum species in Sri Lanka. But the ITS region of the rDNA was shown to be useful to identify species.