PENGARUH ZAT PENGATUR TUMBUH TERHADAP INDUKSI KALUS TANAMAN GAMBIR (Uncaria gambir ROXB.) ASAL PAKPAK BHARAT

The Effect of Plant Growth Regulator on Callus Induction of Gambier (Uncaria gambir Roxb.) from Pakpak Bharat

Abstrak

Callus induction is a crucial stage in plant tissue culture, especially for species such as Uncaria gambir, which holds high potential in the pharmaceutical and agricultural industries. This study aims to evaluate the effectiveness of two combinations of plant growth regulators (PGRs)—2,4-D with kinetin versus NAA with BAP—in inducing high-quality callus based on morphological parameters: time of callus emergence, callus texture, and callus color. The study was conducted using a non-factorial Complete Randomized Design (CRD), consisting of two experimental series. The first series comprised 12 combinations of 2,4-D (0, 1, 2, and 3 ppm) with kinetin (0.5, 1, and 1.5 ppm), while the second series consisted of 20 combinations of NAA (0, 0.25, 0.75, and 1 ppm) with BAP (0, 0.75, 1.5, and 2.25 ppm). The results showed that the combination of 2,4-D at 2 ppm without kinetin produced the earliest callus emergence (7.2 days), with 80% friable texture and a dominant greenish-white color (80%), which are key indicators of meristematic and viable callus. In contrast, NAA–BAP combinations generally resulted in slower callus formation (emergence >15 days), compact texture, and yellowish-white or greenish-white coloration. Statistical analysis revealed significant differences (p<0.05) among treatments, demonstrating that the 2,4-D–kinetin combination is more effective in inducing callus, and recommended as the optimal protocol for callus culture and cell suspension culture in gambier plants.