In vitro mass propagation protocol for BARI lilium-1 adapted in Bangladesh

A micropropagation protocol for BARI Lilium-1 (Lilium longiflorum) was developed using stem nodes as explants to enable large-scale cultivation in Bangladesh. Explants were surface sterilized with 0.2% Ridomil gold (20 min), followed by detergent solution (10 min) and finally with commercial bleach (60% chlorox). Sterilized explants were cultured on Murashige and Skoog (MS) medium containing varying concentrations and combinations of BAP, NAA, IAA and IBA for shoot bud initiation with multiple shooting. Subsequently, for root induction, different concentrations of IBA and NAA were examined individually. The highest percentage of explant-producing shoot buds (93%), the greatest number of bulblets (31.66) and the longest bulblets (11.49 cm) were achieved with MS medium containing 1 mg/L each of IAA and IBA. Optimal rooting, with 6.65 roots per bulblet within the shortest time (10.55 days), was achieved in MS medium supplemented with 0.5 mg/L NAA. Most of the bulblets were easily acclimatized and showed 100% survival during primary hardening in a soil and coco peat (1:2) mixture, demonstrating the robustness of this protocol. This study highlights a reproducible and efficient tissue culture method for mass propagation of BARI Lilium-1 within a shorter period of time, which will greatly benefit the cut flower industry in Bangladesh. The study optimized growth regulator combinations and hardening conditions, enhancing shoot bud proliferation, bulblet formation, and plantlet survival, ensuring efficient in vitro to ex vitro transition for BARI Lillium-1.