Micropropagation of Japanese Honeysuckle (Lonicera japonica) and Amur Honeysuckle (L. maackii) by Shoot Tip Culture

Reliable micropropagation protocols were developed for Japanese honeysuckle (Lonicera japonica Thunb.) and Amur honeysuckle [L. maackii (Rupr.) Maxim], two horticulturally important invasive woody plants. Shoot tips were collected from mature plants and established in vitro on Murashige and Skoog (MS) medium and cultured in various media. Plant growth regulators and basal media had significant effects on proliferation rates. Proliferation of Japanese honeysuckle was highest on Driver and Kuniyuki walnut (DKW) medium with 5 μM (1.1 ppm) 6-benzyladenine (BA), yielding an average of 14 axillary microshoots in 12 weeks, whereas Amur honeysuckle produced 38 axillary microshoots in 12 weeks on MS medium containing 2.5 μM (0.6 ppm) BA with or without 1.25 μM (0.3 ppm) indole-3-butyric acid (IBA). Microcuttings of Japanese honeysuckle were rooted ex vitro with or without treatment with 980 μM (200 ppm) IBA, whereas microcuttings of Amur honeysuckle required treatment with 980 μM (200 ppm) IBA to root. These protocols can be used to continuously produce plant materials for various biotechnological modifications, such as in vitro mutations and genetic engineering for noninvasiveness.