Adventitious Root Induction in Cinnamomum heyneanum and C. riparium: The Endemic Tree Species of Western Ghats

Abstract

Cinnamomum heyneanum Nees and C. riparium Gamble (family Lauraceae) are the two wild riparian species of Cinnamomum endemic to Western Ghats of Peninsular India. Overexploitation along with the lack of efforts replenish the resources have urged the ex situ and in situ conservation of these species. The objective of the present study was to explore the possibility of vegetative propagation through branch cuttings and juvenile epicormic shoots in planting stock production of these species. The effect of cutting type, time of collection, auxin type and auxin concentration on adventitious rhizogenesis of branch cuttings and epicormic shoots were studied. Results indicated that all these factors significantly affected the rooting efficacy of cuttings. The branch cuttings of C. heyneanum recorded a maximum rooting of 69.0 ± 2.0% and that of C. riparium was 70.7 ± 7.4%. The highest percentage of rooting was obtained in semi-hardwood cuttings treated with IBA 7000 mg l−1collected during September–December. Meanwhile, the juvenile epicormic shoots under best treatment combination could produce rooting up to 94% in C. heyneanum and 93% in C. riparian. The highest sprouting and rooting were observed in the epicormic shoots produced in the cuttings collected during January to April treated with 5000 mg l−1 IBA. The present study reveals that both the Cinnamomum species are amenable to macro-propagation and a better sprouting and rooting response can be obtained by using juvenile epicormic shoots compared to branch cuttings.