Propagation of Jasminum parkeri: A Critically Endangered Wild Ornamental Woody Shrub from Western Himalaya

Abstract

Jasminum parkeri Dunn is a narrowly endemic, critically endangered woody ornamental shrub confined to sub-temperate zone of Western Himalayas, and rediscovered from its type locality after a lapse of about 100 years. In the present study, a propagation technique of J. parkeri, using stem cuttings, was established for the first time through application of auxins, namely, indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA), at varying concentrations ranging from 1000 to 4000 ppm. The highest rooting percentage (98.33% (85.68% ± 4.32)), number of primary roots (36), root length (29.68 cm) and survival percentage (96.67% (83.85% ± 6.16)) were recorded for cuttings treated with 3000 ppm NAA. The phenological comparison between pot plants propagated through seeds and stem cuttings in a naturally ventilated polyhouse revealed a reduction in vegetative and flowering phases in cutting raised plants. Additionally, a noteworthy adaptive behavior of two weeks of early flowering and four weeks of extended flowering (February to October) was observed in plants raised under polyhouse conditions. This method will help in protecting the species from population decline, thereby significantly increasing its potential to be harnessed as an ornamental plant in India. Furthermore, plants grown ex situ will be reintroduced in natural populations.