Morphological and Biochemical Characterization of a Representative Collection of Cinnamomum verum J. Presl Germplasm in Sri Lanka

Abstract

Determination of morphological and biochemical diversity of cultivated cinnamon (Cinnamomum verum) is instrumental in breeding new varieties. A representative cinnamon collection of 18 genotypes in the Faculty of Agriculture, University of Ruhuna was used to determine leaf morphology, leaf essential oil yield and composition, and the shoot regeneration capacity. Leaf morphology was measured using Descriptors for Cinnamon. Leaf length, width, and petiole length ranged from 7.9-13.4 cm, 3.9-7.1 cm, and 1.2-2.0 cm respectively. The flush colour was determined into four main categories pink, red, brown, and green. GCMS analysis for leaf oil in two times during 2018 and 2021 revealed that Eugenol (EU) was the major compound (52.2% to 79.5%) in 15 accessions. Accessions KA11 and GB17 with zero EU reported 86.8% and 91.9% of benzyl benzoate (BB), and in contrast to that of 0%-0.65% from other accessions in 2019. KA11 and GB17 produced 0.82% and 10.37% of EU with 72.44% and 55.5% of BB in 2021. HB12 produced 16.6% and 38.15% EU and 22.3% and 52.63% BB in 2019 and 2021 respectively. The leaf oil yield of the collection ranged from 0.84% (KA11) to 5.26% (MKG13). Both A and B flower types of protogynous dichogamy were recorded. The shoot regeneration capacity of accessions ranged from 4% (2MDS4) to 75% (GK17). The dendrogram based on the principal component analysis of 42 morphological and biochemical characters produced five clusters at a rescaled distance of 0.075 making GB17 a distinct cluster. Therefore, accessions with distinct chemical profiles will be useful for specific industrial needs in the future.