Development of a core collection for Sri Lankan cinnamon germplasm based on morphological characterization using an eco-geographic survey

Cinnamomum verum is the most important spice produced by Sri Lanka. This study was carried out to fill the gap of knowledge on diversity of Sri Lankan cinnamon through morphological characterization. Therefore, an eco-geographic survey in major growing areas followed by the development of a core collection and vegetative propagation of the total collection for ex-situ conservation were carried out. Two hundred and sixty nine cinnamon accessions were collected. The average shoot regeneration frequency of 269 accessions was 47.76% after one month of vegetative propagation. The collection was established at Faculty of Agriculture, University of Ruhuna for further studies. The collection was characterized for 15 quantitative and qualitative characters of leaf, stem and inflorescence among which, a wide variation was detected for leaf characters mainly. Leaf length positively correlated with Leaf width (+0.643) and Petiole length (+0.483). Principal component analysis (PCA) revealed that there were 3 dimensions of PCA explaining 88.85% of total variance. In Hierarchical cluster analysis based on above characters, 269 accessions were grouped into five clusters at rescaled distance of 0.1. A representation of 10% accessions was randomly selected from each cluster to develop a core collection with 33 accessions. The core collection of 33 accessions was clustered into five groups according to the same method at rescaled distance of 0.075. The core collection is a representation of the total collection as clusters of the two dendograms could be overlapped. Morphological characterization and core collection development during this study will be useful for germplasm management, conservation and varietal improvement through breeding programmes.