Improved protocol for micropropagation of genetically uniform plants of commercially important cardamom (Elettaria cardamomum Maton)

Abstract

Cardamom (Elettaria cardamomum Maton) is a highly valuable commercial spice crop, originating from the Western Ghats of southern India. It has importance both as a spice and for its medicinal properties. An efficient and reliable micropropagation protocol using shoot tips as explants is presented which can be utilized for development of elite planting material. Growth patterns of cardamom shoots were analyzed on 45 media treatments and best shoot proliferation was recorded on Murashige and Skoog (MS) medium supplemented with 4.4 μM 6-benzylaminopurine (BAP) and 2.32 μM kinetin (Kn) with 5.83 shoots regenerated per explant. The longest shoots (6 cm) were observed on 0.44 μM BAP and 2.32 μM Kn containing medium. Regenerated shoots rooted well on full strength MS basal medium, generating 3.50 roots per explant with an average root length of 4.33 cm within 4 wk. Successful hardening with a field survival percentage of 80% was achieved after acclimatization of well-developed plantlets. Genetic stability of the micropropagated plants was confirmed using 13 ISSR markers. This study reports an improved micropropagation protocol for cardamom with an enhanced rate of shoot multiplication leading to the production of healthy shoots which can be easily rooted and successfully transferred to the field.