Effects of BAP, NAA and AgNPs on in vitro regeneration of Bajra Napier hybrid grass through direct organogenesis

Bajra Napier, an interspecific hybrid of bajra (Pennisetum glaucum L.) and napier (Pennisetum purpureum Schum.), belongs to the Poaceae family and is commonly known as King grass. This fodder crop provides excellent green forage throughout the year in tropical climates. The study on “Effects of BAP, NAA and AgNPs on in vitro regeneration of Bajra Napier hybrid grass through direct organogenesis” was conducted at the Tissue Culture Laboratory of the NSP/BSP Seed Unit, University of Agricultural Sciences, Dharwad, during 2023-24. Among the two growth regulators tested (BAP and AgNPs) at various concentrations, BAP at 2.0 mg/l yielded the highest frequency of shoots per explant (5.16). Among the cultivars studied, CoBN-5 demonstrated superior performance with a greater number of shoots per explant (4.38), longer shoot length (20.56 cm) and a shorter initiation time (3.67 days). Significant differences were observed among treatments regarding explant survival percentage, mean shoot length and number of shoots per explant, with the control group showing lower results. In interactions, CoBN-5 combined with BAP at 2.0 mg/l produced a significantly higher number of shoots per explant (5.88), increased shoot length (27.67 cm), a survival rate of 52.4% and quicker initiation time (2.42 days). For rooting microshoots, the MS medium supplemented with 1.0 mg/l NAA achieved the higher rooting percentage, number of roots and longer primary root. Among interactions, CoBN-5 with 1.0 mg/l NAA showed the higher rooting percentage (39.02%), the greater number of roots (7.63) and longer primary root (4.87 cm).