Trait Diversity and Essential Oil Yield in Cinnamon: A Half-sib Genetic Study from Central Western Ghats, India

Cinnamomum zeylanicum, known as 'true cinnamon,' is an economically significant species valued for its spice and essential oil, particularly its high eugenol content. This study assessed the growth traits, leaf oil yield, eugenol content and reproductive parameters among 15 half-sib families of C. zeylanicum from the Central Western Ghats, India, with the objective to identify superior genotypes for genetic improvement. The progeny trial conducted at Bakkal Botanical Garden near Sirsi, Uttara Kannada district of Karnataka. Plant height, girth, branching, leaf count, inflorescence and immature fruit production of two-year-old progenies were recorded. Significant variability was observed in growth traits. Family G11 exhibited superior vegetative growth with maximum plant height (213.33 cm) and leaf production (677.66 leaves/plant), while K16 showed the maximum basal girth (51.46 mm). Leaf oil content ranged between 1.30 and 2.20 per cent (dry weight basis), where J6 achieved the highest oil yield. Eugenol content varied from 55.78 to 89.43 per cent among half-sib families where family S5 recorded the highest concentration. The negative correlation was recorded between total oil yield and eugenol concentration, indicating the importance of strategic balancing in selection breeding. Moreover, reproductive traits also showed variation and family J2 produced the highest number of inflorescence and immature fruits per plant. Study concludes that families such as G11, J6, K16, S5 and J2 can be considered as elite germplasm for future breeding and improvement programs. These findings provide an essential insight for enhancing both yield and quality of cinnamon, contributing to sustainable industry development.