Propagation Through Air Layering in Zanthoxylum armatum DC: An Endangered Medicinal Plant in the Himalayan Region

Abstract

In the recent years medicinal plants are receiving attention due to the presence of therapeutically important active contents; however over exploitation is the major concern for conservation of several medicinal species. An attempt has been made to develop a propagation method through air layering in Zanthoxylum armatum DC, a medicinally important plant used in various traditional and modern medicines. Various concentrations of auxins as indole-3-butyric acid (IBA) and α-naphthalene acetic acid (NAA) at 0.01, 0.05, 0.1, 0.5 and 1.0 mM each were applied to the stem branches (still attached to the plant) during the rainy season and following root formation, the stems were detached from mother plants and transplanted in the soil (under mist chamber conditions). Plants treated with 0.1 mM NAA resulted in maximum plant survival (90 %), root number (142 ± 6.74) and root length (16.8 ± 1.04 cm) in 28 weeks. The higher concentrations of the IBA and NAA (0.5 mM) significantly decreased the percentage rooting and no root formation was observed in 1.0 mM concentration. The results of the present study can be used for mass multiplication of the species as an inexpensive and convenient way of propagation.