In vitro organogenesis techniques in black bamboo (Phyllostachys nigra)

Abstract

In vitro organogenesis protocol for Phyllostachys nigra (Black bamboo) was developed, a commercially valuable and ornamental bamboo species. Due to limitations associated with traditional propagation methods such as unpredictable flowering behaviour, low seed viability and high contamination, micropropagation through tissue culture has emerged as a promising solution for large-scale propagation of this species. This study, conducted at the Plant Biotechnology Centre, DBSKKV, Dapoli during 2024-2025, focused on standardizing multiple aspects of in vitro culture, including explant selection, sterilization techniques, media composition, shoot multiplication, rooting and hardening. Among the various sterilization treatments treatments of axillary nodal explants, the effective treatment with Carbendazim (0.2%), Streptomycin (0.2%), Sodium hypochlorite (5%), Hydrogen peroxide (0.2%), Mercuric chloride (0.15%) and (70%) ethanol recorded the highest aseptic culture establishment (45.00%) with a (50.00%) survival rate. Axillary nodal explants, showing a sprouting rate of (84.00%) and a survival rate of (76.66%). Explants measuring 3.0 cm in length and 2.5 mm in diameter demonstrated the highest shoot induction (9.67 shoots/explant). Murashige and Skoog (MS) medium supplemented with 4.0 mg/l BAP was most effective for shoot initiation (86.50%), while 4.5 mg/l BAP promoted maximum shoot multiplication (9.00 shoots/explant). For root induction, MS medium supplemented with 1.0 mg/l IBA and 1.0 mg/l NAA recorded the best rooting response (87.50%), resulting in an average of (9.66 /propagule) within 12 days. During hardening, a potting mixture of soil, vermicompost, and cocopeat in a 1:1:1 ratio ensured the highest plantlet survival rate (83.73%). The standardized protocol established through this study provides a sustainable method for the mass multiplication of Phyllostachys nigra, contributing to its conservation and commercial cultivation.