Development and characterization of kithul flour (Caryota urens) based alternative tissue culture media for agar

Abstract

Plant tissue culture uses an artificial culture medium containing macronutrients, micronutrients, organic supplements, growth regulators, and solidifying agents to grow the explants. Agar is the common gelling agent used for solidification of the growth media, which contributes 70% of the cost of culture media preparation. This study explores a cost-effective alternative to agar-based plant tissue culture media. Kithul flour, characterized by its favorable gelling properties and nutrient content, was investigated. The study evaluated kithul flour's composition, moisture content (11.14%), pH (6.15), ash content (6.32%), amylose (18.84%), crude fat (6.21%), swelling power (9.02%), and solubility (4.89%). Alternative growth media were prepared by blending kithul flour with MS media powder, macronutrients, micronutrients, sucrose, and myo-inositol. Varying agar-to-kithul flour ratios were tested. (Agar: Kithul flour = 5:0, 4:1, 3:2, 2:3, 1:4, 0:5). Observations revealed that kithul flour excelled in gelling capacity, particularly at a 3:2 ratio. Preliminary findings suggest that a 3:2 kithul flour-to-agar ratio offers a cost-effective alternative to 100% agar-based culture media. In the context of micropropagation of Brassica spp., the kithul flour-gelled medium consistently provided a stable gel surface throughout the culture period. This resulted in enhanced plantlet growth, with increased shoot numbers, shoot length, and leaf count. The six treatments included an agar-to-kithul flour ratio (T0 = 5:0, T1 = 4:1, T2 = 3:2, T3 = 2:3, T4 = 1:4, and T5 = 0:5). Statistical analysis was done using Minitab software and found significant differences (P < 0.30) in shoot regeneration based on the gelling agents used in combination with agar. The study introduces a promising alternative to costly agar-based culture media, with kithul flour demonstrating excellent gelling properties and supporting optimal plantlet growth in Brassica spp. micropropagation.