Use of liquid culture medium and ex vitro rooting for micropropagation of Acacia nilotica (L.) Del. ssp. cupressiformis

A micro-propagation method using liquid culture medium has been developed for Acacia nilotica ssp. cupressiformis . Nodal segments obtained from mature tree (15–20 years old) was used as explants for bud breaking and multiple shoot induction. MS liquid medium with 2.0 mg l −1 of 6-benzylaminopurine (BAP) was the best for shoot bud induction. Further shoots multiplication was achieved by subculturing of in vitro produced shoot clumps (2–3 shoots) in liquid medium supplemented with various concentrations of BAP. Maximum number of shoots (12.57 ± 0.37) and shoot length (10.11 ± 0.42) were recorded in MS liquid medium supplemented with 1.0 mg l −1 of BAP. About 90 % shoots rooted ex-vitro on soilrite within 3–4 weeks when base (3–5 mm) of shoots was treated with 300 mg l −1 of indole-3-butyric acid for 5 min. The plantlets were hardened successfully in the green house and transferred to the polybags. To the best of our knowledge, this is the first report of a micro-propagation protocol for A. nilotica ssp. cupressiformis.