2020, VOLUME 7 ISSUE 1Pages: 149-157
Morphometrics of selected Dendrobium spp. (Orchidaceae) in Sri Lanka
P. M. H. Sandamali, S. P. Senanayake* and S. Rajapakse
*Department of Plant and Molecular Biology, University of Kelaniya, Kelaniya, Sri Lanka
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Morphometric analyses of five species of Dendrobium (Orchidaceae) found in Sri Lanka; D. aphyllum, D. crumenatum, D. heterocarpum, D. nutans and D. panduratum were carried out to infer their phenetic relationships. Thirty-one morphological characters were considered; six vegetative and twenty-five floral, of which five were qualitative and twenty-six were quantitative characters. The data were subjected to Cluster Analysis (CA) and Principal Component Analysis (PCA). Cluster analysis has produced two prominent clusters, D. aphyllum, D. nutans and D. panduratum as cluster 1 and D. crumenatum and D. heterocarpum as cluster 2. Both D. nutans and D. panduratum are producing small sized floral parts, compared to D. aphyllum hence exhibits close similarities in floral morphology which resulted in forming a cluster of most closely related species with least dissimilarity values. With respect to many characteristics, two species incluster 2, D. crumenatum and D. heterocarpum, are found to be similar except for the leaf thickness. Furthermore, PCA also in agreement with the relationships derived from the cluster analysis. The present taxonomic study has revealed that in inferring phenetic relationships of Dendrobium spp. both vegetative and floral characters are influential.